Author SHA1 Message Date
haylan a3f1099bfc docs(research): OmniRoute memory tools hijack classifier tool-call, x-omniroute-no-memory fix 2026-09-15 23:31:58 +02:00
haylan ed90256f43 docs(research): trace 48-min outage to third OmniRoute timeout and open ROCm#6630 GPU hang 2026-09-15 23:31:58 +02:00
haylan fa852c8fb4 docs(research): qwen-classifier needs no context-window match; 8B/30B won't fit VRAM 2026-09-15 23:31:58 +02:00
haylan 2250e804db Implement code changes to enhance functionality and improve performance 2026-09-11 13:15:30 +02:00
haylanandClaude-Bot e31647812a fix(omniroute): raise REQUEST_TIMEOUT_MS and enable --cache-reuse to stop non-ping SSE stream aborts
STREAM_IDLE_TIMEOUT_MS was raised to 180s on 2026-09-09 to give contended
llama-server prefill room to produce a first token, but qwen-code sessions
kept hitting "Stream produced no non-ping SSE event within 95000ms" the very
next morning. Per OmniRoute's own docs, that's the wrong timer: the first
non-ping SSE event's deadline inherits REQUEST_TIMEOUT_MS (default 10 min,
computed as remaining budget after retries/cooldowns), not
STREAM_IDLE_TIMEOUT_MS (which only bounds gaps between chunks once streaming
has already started).

Two changes:
- Add REQUEST_TIMEOUT_MS=1800000 (30 min) on the omniroute service, exposed
  as OMNIROUTE_REQUEST_TIMEOUT_MS like the existing stream-idle var. Safety
  margin, not the root-cause fix.
- Add --cache-reuse 256 to llama-server: it had no KV-cache reuse configured,
  so every request reprefilled its full prompt from scratch even when most
  of a conversation's prefix was unchanged. This is the actual fix for why
  compact-prompt prefill was slow enough to hit the timeout in the first
  place.

Documents the distinction and root cause in docs/research/.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WqWBahogLCkrXNfzCSvcVc
2026-09-10 10:12:02 +02:00
haylanandClaude-Bot 930e407053 docs(llm): document qwen-classifier reality, add --reasoning off safety net
- docker-compose.yml: add --reasoning off to qwen-classifier per
  fast-model-choice.md's own recommendation (ggml-org/llama.cpp#20809
  safety net) — missed in the original rollout, caught while writing
  this up.
- docs/coding-cli-setup/qwen-code.md: rewritten to match what's actually
  deployed (qwen-classifier, partial GPU offload, 65536 ctx, Q4_K_XL) —
  previously described an unimplemented llama-server-fast/8192-ctx plan.
  Documents the non-interactive MCP tool allow-list gap found live-testing.
- docs/coding-cli-setup/opencode.md: fix stale 65536 example that didn't
  match its own documented LLAMA_CTX_SIZE/LLAMA_PARALLEL formula (131072).
- docs/research/fast-model-choice.md: implementation note recording where
  the actual rollout diverged from this doc's original recommendations
  (service name, quant, context size, CPU-first-then-GPU path).
- docs/research/omniroute-account-semaphore-timeout.md: new — the
  hardcoded 30s per-connection semaphore timeout found during the
  pr-agent investigation, root-caused against OmniRoute's own source,
  and the maxConcurrent:null + providerSpecificData.timeoutMs fix.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 19:10:32 +02:00
haylanandClaude-Bot 76043e2c6f tune(llm): partial GPU offload for qwen-classifier, real headroom
Full offload (999 layers) left only ~768MB free VRAM regardless of
batch-size/flash-attn tuning — that gap tracks roughly fixed regardless
of those knobs, most likely ROCm's own per-process HIP context overhead
(same ROCm#5706 quirk already noted for two HIP contexts sharing this
card, see llama-server's GPU_MAX_HW_QUEUES comment above). Dropping to
28/36 layers on GPU (6 layers + their KV on CPU) trades a slice of
speed for real freed VRAM — still >80% of layers on GPU, nowhere near
CPU-only's unusable latency. Verifying live before locking this number in.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 18:10:39 +02:00
haylanandClaude-Bot 1102273384 fix(llm): enable flash-attn on qwen-classifier, real VRAM cause found
Batch/ubatch reduction barely moved measured VRAM (~768MB free, same as
before) — wrong lever. llama-server runs with --flash-attn on; this
service didn't. Without it, the unfused attention compute buffer at
65536 ctx is far larger than flash-attn's fused workspace, which is
what the naive weights+KV estimate missed. Matches llama-server's flag.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 17:04:05 +02:00
haylanandClaude-Bot ba9ace6f71 fix(llm): shrink qwen-classifier's compute buffer for real VRAM headroom
Measured live: full-offload weights+KV (~4.9GiB estimate) actually used
~5.85GiB, leaving only ~700MB free on the R9700 — too tight, real OOM
risk for either GPU process. The gap was compute-buffer/graph overhead
the naive estimate didn't account for. Drop --batch-size/--ubatch-size
well below llama-server's defaults (2048/512) to shrink it — a
single-request classifier has no batching throughput to lose.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 17:02:44 +02:00
haylanandClaude-Bot 8e2650807c fix(llm): move qwen-classifier to GPU, right-size context
CPU-only was too slow in practice: real classification calls blew past
OmniRoute's 60s timeout and retry-looped (504/499). Moved to GPU.

Also traced qwen-code's actual classifier transcript cap in its source
(MAX_TRANSCRIPT_MESSAGES=40, MAX_HISTORICAL_ACTION_CHARS=4000/message) —
worst case is ~40-50K tokens, not the 131072 originally set in
settings.json (copied from the main model's entry, not a real qwen-code
requirement). Dropped ctx-size to 65536 (~1.5x margin) so Q4_K_XL
weights + q4_0/q4_0 KV fit fully on GPU (~4.9GiB) inside the ~6.1GiB
free on the R9700, instead of needing partial CPU/GPU offload.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 16:59:02 +02:00
haylanandClaude-Bot 4353e5c0e8 merge: follow-up fix for qwen-classifier model file
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 16:38:11 +02:00
haylanandClaude-Bot 20cc0bcc70 fix(llm): point qwen-classifier at the Q8 GGUF already on disk
The Q4_K_M-class file this originally specced didn't exist yet on
gameserver (classifier crash-looped: "No such file or directory").
A Q8_K_XL GGUF for the same model was already sitting in the models
volume from something earlier — point at that instead of downloading a
new file, and drop the KV cache quant to q4_0/q4_0 to keep total RAM
comfortable now that the weights are the larger Q8 variant.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 16:37:54 +02:00
haylan c1e30ec9bb Merge pull request 'Fix/omniroute pr agent timeout' (#54) from fix/omniroute-pr-agent-timeout into main
Reviewed-on: #54
2026-09-09 14:29:13 +00:00
haylan b3a64fe4b5 chroe(chore): added markdown for harnesses 2026-09-09 16:28:42 +02:00
haylanandClaude-Bot 828bd4c046 feat(llm): dedicate a CPU-only backend for the qwen-code tool-call classifier
fastModel in ~/.qwen/settings.json (permissions.autoMode.classifier) was
aliased onto llama-server's own 27B connection, so every tool-call safety
check queued behind whatever heavy generation was already running on that
model's 2 GPU slots.

Add qwen-classifier: a separate llama.cpp instance, CPU-only, running
Qwen3-4B-Instruct-2507 (the smallest Qwen3 with native >=131072 context,
qwen-code's requirement, without lossy RoPE scaling). Structurally isolated
from llama-server's queue instead of sharing it. Sized for gameserver's
~17GiB free system RAM: q8_0/q8_0 KV at full 131072 ctx (~9.8GiB) + Q4_K_M-
class weights (~2.3GiB) fits comfortably, with better KV quality than the
q4_0 that would've been needed to fit this on the GPU's ~6GiB free VRAM.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-09 16:26:51 +02:00
15 changed files with 1939 additions and 82 deletions
+22 -10
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@@ -29,18 +29,25 @@ LLAMA_GPU_LAYERS=999
# this size) — total ~25.6GB, ~6GB headroom, the same footprint the old
# 131072 fp16 setting used. See docs/research/qwen3.8-27b-quant.md.
LLAMA_CTX_SIZE=262144
# Concurrent request slots. Was implicitly 4 (llama.cpp's compiled-in
# default) with no flag set — under concurrent subagent fan-out, 4 requests
# split the same GPU compute, so a large-context prefill can queue behind
# others long enough to blow past OmniRoute's stream-idle timeout, which then
# cancels the request (see issue-tracker notes on the timeout/cancel loop).
# Dropped to 2 so each slot gets more compute and finishes prefill sooner;
# raise back toward 4 if throughput (not latency) becomes the bottleneck
# instead. Each slot gets LLAMA_CTX_SIZE / LLAMA_PARALLEL tokens of context —
# real sessions have hit ~66K tokens, so don't drop LLAMA_CTX_SIZE without
# checking that per-slot number stays comfortably above observed usage.
# Concurrent request slots — the real hardware ceiling for this GPU, not a
# tunable to raise for throughput (was implicitly 4, llama.cpp's compiled-in
# default; dropped to 2 because more contended prefill was blowing requests
# past OmniRoute's idle timeout — see OMNIROUTE_STREAM_IDLE_TIMEOUT_MS below).
# The 3rd+ request now queues on llama.cpp itself instead — its own queue has
# no timeout (tools/server/server-queue.cpp), it just waits for a slot — so
# the timeout that matters moved to OmniRoute's per-connection
# providerSpecificData.timeoutMs (dashboard/API only, not in this file; see
# handoff notes in the issue tracker). Each slot gets LLAMA_CTX_SIZE /
# LLAMA_PARALLEL tokens of context — real sessions have hit ~66K tokens, so
# don't drop LLAMA_CTX_SIZE without checking that per-slot number stays
# comfortably above observed usage.
LLAMA_PARALLEL=2
# Dedicated GPU-resident backend for qwen-code's tool-call harmfulness
# classifier (fastModel in ~/.qwen/settings.json) — see docker-compose.yml's
# qwen-classifier service comment for the why and the VRAM/context math.
LLAMA_CLASSIFIER_MODEL_FILE=Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf
# --- Lazytainer ---
# Seconds of inactivity before llama-server is stopped. 900 = 15 min.
LAZYTAINER_INACTIVE_TIMEOUT=900
@@ -64,6 +71,11 @@ OMNIROUTE_DASHBOARD_PORT=20128
# cancels it (which cancels the matching llama-server task too). 180s gives
# contended prefill (see LLAMA_PARALLEL above) room to produce a first token.
OMNIROUTE_STREAM_IDLE_TIMEOUT_MS=180000
# Wait budget for the *first* SSE token specifically (distinct from the
# inter-chunk timeout above) — see
# docs/research/omniroute-non-ping-sse-stream-timeout.md. 30 min covers a
# contended, large-context prefill even after retries eat into the budget.
OMNIROUTE_REQUEST_TIMEOUT_MS=1800000
# Random values, filled in automatically by ./scripts/update.sh — leave
# blank. Bootstrap dashboard admin password (log in at the dashboard port,
# change it there afterwards — this is only the first-boot value):
+1 -2
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@@ -1,2 +1 @@
# AGENTS.md
Agent instructions for this repo live in [CLAUDE.md](./CLAUDE.md) — read it before working here.
@CLAUDE.md
+1 -57
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@@ -1,57 +1 @@
# QWEN.md
Agent instructions for working in this repo (issue tracker, domain docs, mandatory deploy flow) live in [CLAUDE.md](./CLAUDE.md) — read it first.
## Project Overview
Local AI inference stack for a single AMD Radeon AI PRO R9700 (32GB VRAM, gfx1201/ROCm) homelab box. Not a code project — it's a **Docker Compose deployment** plus operational docs and scripts. The stack:
- **llama.cpp (ROCm)** serves Qwen3.8-27B (`Qwen3.8-27B-UD-Q4_K_XL.gguf`, fully GPU-resident, 262K context with q8_0 KV cache). Internal-only: no published host port, no auth of its own.
- **OmniRoute** (AI gateway, replaced LiteLLM in issue #31) fronts everything: per-workload API keys, usage tracking, SearXNG-backed web search. Split ports: API `${OMNIROUTE_API_PORT:-20129}`, dashboard `${OMNIROUTE_DASHBOARD_PORT:-20128}` (dashboard is host/LAN-only, never published externally).
- **ComfyUI** (yurisasc's ROCm image, gfx1201-tuned) for local image generation (Qwen-Image FP8). Shares the GPU with llama-server — **never runs concurrently** with it; use `./scripts/switch-model.sh`.
- **Lazytainer** auto-suspends llama-server after idle (15 min default). Note: its packet-threshold detector can't reliably distinguish OmniRoute's health pings from real traffic (issue #40) — the scripted swap in `switch-model.sh` exists because of this.
- **RAG stores**: Qdrant (vector, 6333) + Neo4j (graph, 7474/7687).
- All services live on the `ai-stack` docker network. External clients reach the gateway via `proxy-ai.home` / `proxy-ai.haylan.ch` (Nginx Proxy Manager); see `docs/network-access.md`.
Coding CLIs (Claude Code, Kimi, OpenCode, Qwen Code) point at the gateway, never at llama-server directly — see `docs/coding-cli-setup/index.md`.
**Known risk**: Qwen3.8-27B tool-calling against llama.cpp's Anthropic shim has open upstream parser bugs — see `docs/research/qwen3.8-27b-tool-calling.md`. Don't trust it for unattended agentic work until smoke-tested (issues #5, #17).
## Key Files
| File | Purpose |
|---|---|
| `docker-compose.yml` | The whole stack. Comments in it are load-bearing (ROCm GID workarounds, GPU_MAX_HW_QUEUES, timeout rationale) — read before editing. |
| `.env.example` | Defaults for every tunable. Secrets/host-resolved values are blank and auto-filled by `update.sh`. |
| `scripts/update.sh` | **The one command to run after any repo change** on the server. Creates `.env`, fills blank secrets (openssl), resolves `SEARXNG_LAN_IP`/GIDs, syncs tunables from `.env.example` (conflicts are interactive or hard errors non-interactively), downloads missing model files, pulls/builds, recreates only what changed. Idempotent. |
| `scripts/switch-model.sh {qwen\|comfyui}` | Manual GPU-residency swap between llama-server and comfyui. |
| `docs/proxy-key-onboarding.md` | Minting per-workload API keys (manual, dashboard-only — no scripted flow yet, issue #37). |
| `docs/coding-cli-setup/` | Per-CLI endpoint/wire-format/config recipes. |
| `docs/research/` | Research trail behind every major decision (model choice, quant, ROCm quirks, gateway selection). Read the relevant doc before re-litigating a decision. |
| `docs/agents/issue-tracker.md` | Gitea/`tea` CLI conventions for this repo's issue tracking. |
| `docs/agents/domain.md` | How to consume `CONTEXT.md` + `docs/adr/` (both may not exist yet — proceed silently if absent). |
## Working in This Repo
### Deploying changes — mandatory flow
The running stack lives on a **separate box** (the R9700 server), not wherever this repo is edited. After any change to `docker-compose.yml`, `.env.example`, or a `scripts/` file:
1. Commit and push.
2. Run `./scripts/update.sh` **on the server** to apply it.
3. If this session has no shell access to the server, say so explicitly and tell the user to run it — never describe a change as done without step 2.
### Issue tracker
Issues live as Gitea issues on `git.arthurerlich.de` (repo `haylan/LLM-Server`). Use the **`tea` CLI** (already authenticated) — conventions in `docs/agents/issue-tracker.md`. Large efforts are tracked via wayfinder map issues (`wayfinder:map` label) with child tickets and native dependency blocking.
### Conventions
- **`ponytail:` comments** mark deliberate simplifications with their known ceiling and upgrade path (e.g. lazytainer timeout tuning lives in compose labels, not a separate config file; no rollback logic in `update.sh``git revert` + re-run is recovery). Keep them when editing nearby code; they encode "why this looks like a shortcut".
- **Secrets stay blank in `.env.example`** and are filled by `update.sh` via `set_if_blank` — never hardcode or commit real secrets. `OMNIROUTE_STORAGE_ENCRYPTION_KEY` and the like must never change after first run (encrypted data becomes unreadable).
- **GPU group access is numeric GIDs** (`HOST_VIDEO_GID`/`HOST_RENDER_GID`), resolved by `update.sh` — don't switch `group_add` to named groups (Docker resolves names against the container's `/etc/group`, not the host's; see `docs/research/rocm-gpu-pin-and-render-group.md`).
- **One-off downloaders** (`downloader*` services) use `test -f` guards so re-runs skip existing files; they run as root because the named volume is root-owned.
- Comments in this repo are unusually dense and explanatory — that's the house style. When changing behavior, update the comment explaining *why*, not just the *what*.
- Tunables with real defaults live in `.env.example`; `update.sh` syncs them into the server's `.env` every run. A divergent server value is a conflict, not a silent overwrite.
@CLAUDE.md
@CLAUDE.md
+111
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@@ -30,7 +30,16 @@ services:
--flash-attn on
--cache-type-k q8_0
--cache-type-v q8_0
--cache-reuse 256
--jinja
# --cache-reuse 256: reuse cached KV for any matching prompt chunk of at
# least 256 tokens (KV-shift, no reprocessing) instead of reprefilling
# from scratch every request. Directly targets the actual root cause
# behind the OmniRoute non-ping SSE timeout, not just the symptom — see
# docs/research/omniroute-non-ping-sse-stream-timeout.md. Pairs with
# OmniRoute's promptCacheAffinityEnabled (dashboard default), which keeps
# a conversation's requests pinned to the same slot so there's a matching
# prefix to reuse.
# No published host port: llama-server is reached only via the omniroute
# gateway on the ai-stack docker network now — see issue #15. Its
# unauthenticated API no longer needs to be LAN-reachable directly.
@@ -46,6 +55,82 @@ services:
- "lazytainer.group.llamaserver.inactiveTimeout=${LAZYTAINER_INACTIVE_TIMEOUT:-900}"
- "lazytainer.group.llamaserver.minPacketThreshold=2"
# Dedicated backend for qwen-code's tool-call harmfulness classifier
# (fastModel in ~/.qwen/settings.json). Was aliased onto llama-server's own
# 27B connection — every classification call then queued behind whatever
# heavy generation was already running on that model's 2 GPU slots (issue
# tracker: OmniRoute semaphore/pr-agent investigation).
#
# Tried CPU-only first (own process avoids the GPU queue entirely) — too
# slow in practice: real classification calls blew past OmniRoute's 60s
# timeout and retry-looped (504→499→504...). Moved to GPU instead.
#
# Context sizing: qwen-code's classifier transcript is hard-capped in its
# own source (MAX_TRANSCRIPT_MESSAGES=40, MAX_HISTORICAL_ACTION_CHARS=4000
# per message, packages/core/src/permissions/classifier-transcript.ts) —
# worst case is ~40-50K tokens, nowhere near the 131072 originally set in
# settings.json (that number was copied from the main model's entry, not
# a real qwen-code requirement). 65536 ctx gives ~1.5x margin over that
# worst case. Qwen3-4B-Instruct-2507 is still the model choice — smallest
# Qwen3 with long native context (262144) without RoPE-scaling, in case
# that margin ever needs to grow.
#
# VRAM: weights+KV math (~4.9GiB) predicted comfortable headroom in the
# ~6.1GiB free on the R9700, but measured live it actually used ~5.85GiB —
# left only ~700MB free, too tight. Dropping --batch-size/--ubatch-size
# barely moved it (~768MB free) — wrong lever. Actual cause: llama-server
# runs with --flash-attn on but this service was missing it — without
# flash attention the unfused attention compute buffer at 65536 ctx is
# much larger (roughly O(n^2) intermediate buffers vs flash-attn's fused,
# near-linear workspace), dwarfing the naive weights+KV estimate. Added
# --flash-attn on to match llama-server; re-verify with rocm-smi after
# deploy before trusting any of these numbers again. GPU_MAX_HW_QUEUES=1
# carried over from llama-server's comment above — same ROCm/ROCm#5706
# clock-pinning bug applies now that two HIP contexts (this +
# llama-server) share the card.
#
# --reasoning off is a no-cost safety net, not a confirmed-needed fix:
# ggml-org/llama.cpp#20809 (closed) documents some server builds
# misdetecting Qwen3-Instruct-2507 models as thinking models, routing
# tool-call output into reasoning_content instead of tool_calls — exactly
# the failure mode that ruled out the 27B model for this role in the
# first place. Whether the current image build still has it was never
# independently confirmed (see docs/research/fast-model-choice.md §4/§6).
qwen-classifier:
image: ghcr.io/ggml-org/llama.cpp:server-rocm
container_name: qwen-classifier
devices:
- /dev/kfd
- /dev/dri
group_add:
- "${HOST_VIDEO_GID:?run scripts/update.sh first to resolve this}"
- "${HOST_RENDER_GID:?run scripts/update.sh first to resolve this}"
security_opt:
- seccomp=unconfined
ipc: host
environment:
- GPU_MAX_HW_QUEUES=1
volumes:
- models:/models
command: >
-m /models/${LLAMA_CLASSIFIER_MODEL_FILE:-Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf}
--host 0.0.0.0
--port 8080
--n-gpu-layers 28
--ctx-size 65536
--parallel 1
--batch-size 512
--ubatch-size 128
--flash-attn on
--reasoning off
--cache-type-k q4_0
--cache-type-v q4_0
--jinja
expose:
- "8080"
restart: unless-stopped
networks: [ai-stack]
# ponytail: one-off downloader, not a standing service — run via
# `docker compose --profile tools run --rm downloader`. Folded into
# scripts/update.sh, which runs this every time; the `test -f` guard is
@@ -67,6 +152,22 @@ services:
curl -L --fail --create-dirs -o /models/${LLAMA_MODEL_FILE:-Qwen3.8-27B-UD-Q4_K_XL.gguf}
https://huggingface.co/unsloth/Qwen3.8-27B-GGUF/resolve/main/${LLAMA_MODEL_FILE:-Qwen3.8-27B-UD-Q4_K_XL.gguf}
# Same pattern as downloader above, separate service so this one small
# file doesn't get re-checked/re-pulled by the big model's job.
downloader-classifier:
image: curlimages/curl:latest
profiles: ["tools"]
user: root
volumes:
- models:/models
entrypoint: ["sh", "-c"]
command:
- >
test -f /models/${LLAMA_CLASSIFIER_MODEL_FILE:-Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf} &&
echo "already downloaded, skipping" ||
curl -L --fail --create-dirs -o /models/${LLAMA_CLASSIFIER_MODEL_FILE:-Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf}
https://huggingface.co/unsloth/Qwen3-4B-Instruct-2507-GGUF/resolve/main/${LLAMA_CLASSIFIER_MODEL_FILE:-Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf}
# Fetches the three Qwen-Image FP8 files ComfyUI needs (diffusion model,
# text encoder, VAE) — same test -f guard pattern as downloader above.
# See docs/research/image-generation-model-choice.md and issue #42.
@@ -191,6 +292,16 @@ services:
# LLAMA_PARALLEL above for the other half of this fix). Raised here so
# it's tracked in git instead of a dashboard-only setting.
- STREAM_IDLE_TIMEOUT_MS=${OMNIROUTE_STREAM_IDLE_TIMEOUT_MS:-180000}
# Different timer than STREAM_IDLE_TIMEOUT_MS above — that one only
# bounds gaps *between* SSE chunks once streaming has started.
# REQUEST_TIMEOUT_MS bounds the wait for the *first* non-ping SSE
# event, and it's what was still firing ("Stream produced no non-ping
# SSE event within 95000ms") the morning after the timeout above was
# raised — see docs/research/omniroute-non-ping-sse-stream-timeout.md.
# Default 600000 (10 min) per OmniRoute's own docs, but the effective
# deadline is remaining budget after retries/cooldowns eat into it, not
# a flat timer, so raised well past the default for headroom.
- REQUEST_TIMEOUT_MS=${OMNIROUTE_REQUEST_TIMEOUT_MS:-1800000}
# Same reasoning as litellm's extra_hosts entry below — ai-stack's bridge
# network can't resolve search.home on its own.
extra_hosts:
+1 -1
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@@ -31,4 +31,4 @@ Both serve the same underlying model — `Qwen3.8-27B-UD-Q4_K_XL.gguf`, register
| [OpenCode](opencode.md) | OpenAI Chat Completions | `http://<ai-box>:${OMNIROUTE_PORT:-4000}/v1` | `opencode.json` provider block |
| [Qwen Code](qwen-code.md) | OpenAI Chat Completions (2 models: chat + `fastModel`) | `http://<ai-box>:${OMNIROUTE_PORT:-4000}/v1` | `~/.qwen/settings.json` `modelProviders.openai` |
Further reading: `docs/research/qwen3.8-27b-tool-calling.md`, `docs/proxy-key-onboarding.md`.
Further reading: `docs/research/qwen3.8-27b-tool-calling.md`, `docs/proxy-key-onboarding.md`, `docs/research/omniroute-account-semaphore-timeout.md` (a connection that can only handle a few concurrent requests — like `llama-server` or `qwen-classifier` — hits a hardcoded 30s reject once more requests queue up than its `maxConcurrent`, unless configured around it).
+1 -1
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@@ -25,7 +25,7 @@ curl -fsSL https://opencode.ai/install | bash
"models": {
"qwen3.8-27b-local": {
"name": "Qwen3.8-27B",
"limit": { "context": 65536, "output": 8192 }
"limit": { "context": 131072, "output": 8192 }
}
}
}
+25 -11
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@@ -2,7 +2,18 @@
[← back to overview](index.md)
Qwen Code speaks plain **OpenAI Chat Completions**, and — unlike the other CLIs — needs *two* models: the main chat model, and a `fastModel` for Auto Mode's action classifier (a separate, always-resident, always-fast instance so classification doesn't queue behind chat prefill; see `docker-compose.yml`'s `llama-server-fast` service and `docs/research/fast-model-choice.md`). Both are registered as separate providers in OmniRoute but reachable through the same gateway URL. Config lives in `~/.qwen/settings.json`:
Qwen Code speaks plain **OpenAI Chat Completions**, and — unlike the other CLIs — needs *two* models: the main chat model, and a `fastModel` for Auto Mode's action classifier. Both are registered as separate providers in OmniRoute but reachable through the same gateway URL.
## Why a second model exists
Auto Mode's action classifier (`permissions.autoMode`) is qwen-code's per-tool-call safety gate — it decides whether to auto-approve or block a shell command / tool call before it runs. It was originally aliased onto the main 27B model's own OmniRoute connection. That broke two ways in practice (see `docs/research/fast-model-choice.md` for the model research, and the issue-tracker history for the full incident):
- **Queued behind heavy work.** Every classification call competed for the main model's 2 GPU slots with whatever real generation was already running, so a classifier check could sit blocked for minutes.
- **CPU-only was tried first and was too slow.** Isolating the classifier onto its own CPU-only llama.cpp instance avoided the GPU queue entirely, but real classification calls (which can carry a non-trivial conversation transcript, not just the bare tool call) blew past OmniRoute's request timeout and retry-looped.
The fix: a dedicated, GPU-resident `qwen-classifier` service (`docker-compose.yml`) running a small model (`Qwen3-4B-Instruct-2507`) on its own **partial** GPU offload — enough layers on the R9700 to be fast, sized to leave real VRAM headroom next to the 27B model rather than trusting a naive weights+KV estimate (see that service's comment block in `docker-compose.yml` for the actual measured numbers and the two wrong turns — batch-size tuning, then flash-attn — before partial offload turned out to be the real lever).
## `~/.qwen/settings.json`
```json
{
@@ -16,12 +27,12 @@ Qwen Code speaks plain **OpenAI Chat Completions**, and — unlike the other CLI
"generationConfig": { "contextWindowSize": 131072 }
},
{
"id": "<fast-model-provider-id-in-omniroute>",
"name": "qwen3.8-27b-classifier",
"id": "<classifier-provider-id-in-omniroute>",
"name": "qwen3-4b-classifier",
"envKey": "OMNIROUTE_API_KEY",
"baseUrl": "http://<ai-box>:${OMNIROUTE_PORT:-4000}/v1",
"generationConfig": {
"contextWindowSize": 8192,
"contextWindowSize": 65536,
"extra_body": { "chat_template_kwargs": { "enable_thinking": false } }
}
}
@@ -32,15 +43,14 @@ Qwen Code speaks plain **OpenAI Chat Completions**, and — unlike the other CLI
"name": "<main-model-provider-id-in-omniroute>",
"baseUrl": "http://<ai-box>:${OMNIROUTE_PORT:-4000}/v1"
},
"fastModel": "<fast-model-provider-id-in-omniroute>"
"fastModel": "<classifier-provider-id-in-omniroute>"
}
```
- `envKey` names the environment variable Qwen Code reads the virtual key from — set `OMNIROUTE_API_KEY=<qwen-code-cli virtual key>` before launching. Both providers can share one virtual key (as above); split it into two if you want separate usage tracking for chat vs. classifier calls.
- **`contextWindowSize` is per-slot, not `LLAMA_CTX_SIZE` itself** — llama.cpp divides `--ctx-size` across `LLAMA_PARALLEL` concurrent slots, and each request only gets one slot's share (same correction applies to OpenCode's `limit.context`). Compute it per model from `.env`:
- Main model: `LLAMA_CTX_SIZE / LLAMA_PARALLEL` = `262144 / 2` = **131072**.
- Fast model: `LLAMA_FAST_CTX_SIZE / LLAMA_FAST_PARALLEL` = `8192 / 1` = **8192**. Undersizing this one specifically breaks Auto Mode ("Classifier stage 1 unavailable") once `hints.allow`/`softDeny`/`hardDeny` entries and recent-action history push a classifier call past it — see the `LLAMA_FAST_CTX_SIZE` comment in `.env.example` before raising it instead of `LLAMA_FAST_PARALLEL`.
- `enable_thinking: false` on the fast model matters: the fast model file (`Qwen3-4B-Instruct-2507`) is already non-thinking, but this also suppresses `<think>` output on any fast-model swap that isn't, keeping classifier responses parseable.
- **`contextWindowSize` for the main model is per-slot, not `LLAMA_CTX_SIZE` itself** — llama.cpp divides `--ctx-size` across `LLAMA_PARALLEL` concurrent slots, and each request only gets one slot's share (same correction applies to OpenCode's `limit.context`). Compute it from `.env`: `LLAMA_CTX_SIZE / LLAMA_PARALLEL` = `262144 / 2` = **131072**.
- **The classifier's `contextWindowSize` (65536) is not per-slot math** — `qwen-classifier` runs `--parallel 1`, so its whole `--ctx-size` belongs to the one slot. 65536 isn't a guess either: qwen-code's own source hard-caps the classifier transcript (`MAX_TRANSCRIPT_MESSAGES=40`, `MAX_HISTORICAL_ACTION_CHARS=4000`/message in `packages/core/src/permissions/classifier-transcript.ts`) — worst case is ~40-50K tokens, so 65536 gives real margin without wasting VRAM the way the original 131072 (copied from the main model's entry, not an actual qwen-code requirement) would have.
- `enable_thinking: false` on the classifier matters for parseability, though `Qwen3-4B-Instruct-2507` is already architecturally non-thinking (see `fast-model-choice.md` §3) — this is belt-and-suspenders for any future fast-model swap that isn't.
- Qwen Code also recognizes `advisorModel`, `visionModel`, `compactionModel`, `imageModel` for other model roles — none are wired up in this stack; only `fastModel` is required.
## Web search via OmniRoute
@@ -96,9 +106,11 @@ Register it in `~/.qwen/settings.json`:
It reuses the same `OMNIROUTE_API_KEY` env var as the model providers above — the virtual key needs search permission in OmniRoute, not just chat-completions.
**Non-interactive mode (`qwen -p ...`) needs this tool explicitly allow-listed.** MCP tools require interactive confirmation by default; `--approval-mode auto` alone doesn't bypass that for a non-interactive run — pass `--allowed-tools mcp__omniroute-search__search` (or `-y` for full YOLO) alongside `-p`, or the search call never reaches the classifier at all and silently no-ops. Confirmed live: without the allow-list, only the tool calls the CLI's non-interactive gate lets through end up as classifier requests.
## Auto Mode tuning
Auto Mode's action classifier calls the fast model above — its own request can queue behind other stack traffic before the fast llama-server instance is warm, so the default classifier timeout is worth raising. And since this stack is a single trusted local proxy, it's reasonable to pre-approve requests to it rather than confirm every call:
Auto Mode's action classifier calls the fast model above. Even on the dedicated GPU-resident instance, give it real timeout headroom rather than trusting OmniRoute's default — and since this stack is a single trusted local proxy, it's reasonable to pre-approve requests to it rather than confirm every call:
```json
{
@@ -111,6 +123,8 @@ Auto Mode's action classifier calls the fast model above — its own request can
}
```
`hints.allow` entries are free-text descriptions the classifier matches against, not exact strings — capped at 150 entries/200 chars each (see the `LLAMA_FAST_CTX_SIZE` note above for why that ceiling matters).
`hints.allow` entries are free-text descriptions the classifier matches against, not exact strings — capped at 150 entries/200 chars each.
Also set a generous per-connection timeout on the classifier's own OmniRoute provider connection (`providerSpecificData.timeoutMs`, dashboard or `PATCH /api/providers/{id}` — not a `.env` value, see `docs/network-access.md` for reaching the dashboard API). 120000ms is comfortable for the current GPU-resident setup (real measured latency: well under a second for a short check, low seconds for the largest realistic transcript) — this isn't the 20-minute figure the main 27B connection needs, since the classifier isn't competing for a contended GPU slot the way the main model can.
Everything else in `~/.qwen/settings.json` (`hooks`, `security.auth`'s underlying tooling, editor prefs) is per-machine, not part of pointing at this stack — don't copy it wholesale between machines.
@@ -0,0 +1,737 @@
# Research: hardware roadmap to 500k-token context × 2 parallel agents (1M stretch)
**Date:** 2026-09-11
**Question:** What VRAM does 500k-token context × 2 parallel llama-server slots (and a 1M-token
stretch goal) actually cost for the Qwen3 family, and what hardware roadmap gets there from the
current single-R9700 setup — given the user's stated plan to add an older (PCIe 4.0) Threadripper
for lane count, reuse existing RAM/PSU (~200W headroom / one spare 8-pin), mix in already-owned
NVIDIA cards (GTX 1080 8GB, RTX 2080 8GB, GT 710 1GB) for the classifier role, and price used GPUs
at roughly $20-30/GB VRAM?
**Answer, short version:** The two goals ("500k × 2 parallel" and "1M stretch") turn out to need
**the same total VRAM budget** — because of how llama-server's `--ctx-size` and `--parallel` interact
(§2), 500k × 2 slots and a single 1M-token slot both require setting `--ctx-size 1000000`. At
`q4_0`-quantized KV cache that's **~33 GB** (weights + KV) for Qwen3.8-27B, at `q8_0` it's **~48 GB**,
at fp16 it's **~79 GB** — before compute-buffer overhead. That does not fit on the current single
32GB R9700 at any KV precision, and comfortably fits on two 32GB-class cards only at `q8_0`/`q4_0`.
The user's $20-30/GB pricing intuition holds for last-gen used consumer cards (RTX 3060 12GB) but
**not** for RTX 3090 24GB (~$44/GB currently) or a second R9700 (~$41/GB, new — no used market yet
for a card released mid-2026). The stated Threadripper plan needs to specifically target the
**non-PRO Threadripper 3000 series on sTRX4** (64 lanes, PCIe 4.0) — older Threadripper on the
original TR4 socket (1000/2000 series) is PCIe 3.0 only, which doesn't match the user's own PCIe 4.0
requirement. The power budget (~200W / one spare 8-pin) is exhausted by a *single* mid-tier used GPU
addition — a PSU upgrade is not optional past the very first stage. See §7 for the roadmap.
---
## 1. Current state (from this repo)
From `docker-compose.yml` and `.env.example` at the repo root:
- **Main model:** `Qwen3.8-27B-UD-Q4_K_XL.gguf` (17.6 GB weights), `--ctx-size 262144`,
`--parallel 2`, `--flash-attn on`, `--cache-type-k q8_0 --cache-type-v q8_0`, `--n-gpu-layers 999`,
on one AMD Radeon AI PRO R9700 (32GB, ROCm/HIP, `gfx1201`).
- **Classifier ("fast") model:** `Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf`, `--ctx-size 65536`,
`--parallel 1`, `--n-gpu-layers 28` (partial offload), `--cache-type-k/v q4_0`, its own container on
the *same* R9700, sharing VRAM with the main model — see
[`docker-compose.yml`](../../docker-compose.yml) lines ~58-99 and
[`fast-model-choice.md`](fast-model-choice.md).
- `.env.example` already documents the exact fact this research turns on: *"Each slot gets
`LLAMA_CTX_SIZE / LLAMA_PARALLEL` tokens of context"* — i.e. today's 262144 ctx-size ÷ 2 parallel
slots means each real request only gets **~131K tokens**, not the full 262144, confirmed in-repo
before any external source was checked.
- Prior research already worked out the KV-cache formula for this exact model
([`qwen3.8-27b-quant.md`](qwen3.8-27b-quant.md)) — this doc reuses and extends that math for the
500k/1M targets rather than re-deriving it.
`docs/server-planing.md` describes a **different, earlier plan**: a 4× AMD Radeon AI PRO R9700 rig
on a Gigabyte MZ32-AR0 (single-socket SP3/EPYC, 128 PCIe 4.0 lanes), fully AMD/ROCm. The user's plan
in this ticket is not that — it pivots toward an older **Threadripper** (SP3's sibling desktop-HEDT
socket family, not SP3 itself) and explicitly wants to mix in already-owned **NVIDIA** cards. These
two plans are **not the same build** and, per §6, ROCm and CUDA cards cannot share one llama.cpp
process — they can only coexist as separate containers on separate cards. Treat `server-planing.md`
as superseded context, not the active plan, unless the user says otherwise.
---
## 2. llama-server parallelism: does each slot get its own full `--ctx-size`, or is it divided?
**Divided.** This is the single fact that changes the whole budget by 2×, confirmed from three
independent primary sources:
1. **This repo's own `.env.example`** (quoted above) already documents it for the current deployment.
2. **llama.cpp's own server README**, fetched directly
([`tools/server/README.md`](https://github.com/ggml-org/llama.cpp/blob/master/tools/server/README.md)):
`--ctx-size (-c)`: *"size of the prompt context (default: 0, 0 = loaded from model)"*;
`--parallel (-np)`: *"number of server slots (default: -1, -1 = auto)"* — the docs list these as
independent flags, but don't spell out the division themselves.
3. **A real user's server log**, quoted verbatim in
[ggml-org/llama.cpp#11681](https://github.com/ggml-org/llama.cpp/issues/11681), is the actual proof:
running with `--ctx-size 327680 --parallel 6` produces `n_ctx = 327680`,
`n_ctx_per_seq = 54613` — i.e. `327680 / 6 ≈ 54613`. The reporter explicitly asked for a
`--ctx-size-per-seq`-style flag to *avoid* this division; no such flag exists as of the fetch date.
Practical consequence: **to get 500,000 usable tokens on each of 2 parallel slots, `--ctx-size` must
be set to 1,000,000, not 500,000.** The KV cache is sized off the *total* `--ctx-size`
(`--kv-unified`, on by default when slots are auto per the README's `-kvu` entry, uses one shared
pool sized to the full `n_ctx`) — so the VRAM cost of "500k × 2 parallel" and "one 1M-token slot"
is **identical**: both require `--ctx-size 1000000`. This is a genuinely useful finding for the
roadmap — reaching the 500k×2 target and the 1M stretch goal cost the same VRAM; the only difference
is `--parallel 1` vs `--parallel 2` at deploy time, a config change with zero extra hardware cost.
`--cache-type-k` / `--cache-type-v` accept `f32, f16, bf16, q8_0, q4_0, q4_1, iq4_nl, q5_0, q5_1`
(default `f16`), per the same README fetch. The repo already uses `q8_0` on the main model and `q4_0`
on the classifier, so both quantization tiers used in the math below are already-proven-working
configurations in this stack, not hypothetical flags.
---
## 3. KV-cache math per model
### Qwen3.8-27B (hybrid Gated-DeltaNet / attention)
Reusing the architecture params already pulled from
[`Qwen/Qwen3.8-27B/config.json`](https://huggingface.co/Qwen/Qwen3.8-27B/raw/main/config.json) in
[`qwen3.8-27b-quant.md`](qwen3.8-27b-quant.md), re-verified directly for this doc: `num_hidden_layers=64`,
`full_attention_interval=4`**16 of 64 layers are standard KV-caching attention**, the other 48 are
Gated DeltaNet linear-attention layers with a small, context-length-*independent* recurrent state
(tens of MB total, negligible next to the attention KV cache — ignored below).
`num_key_value_heads=4` (GQA), `head_dim=256`. Native context `max_position_embeddings=262144`
(YaRN-extensible to 1M per the model card — **both the 500k and 1M targets exceed native context and
require RoPE/YaRN scaling**, which is a real quality caveat, not just a memory one — Qwen has not
published independent long-context quality benchmarks past native length that this research found).
Per-token KV cache, fp16, both K and V, across the 16 full-attention layers:
```
16 layers × 2 (K+V) × 4 kv_heads × 256 head_dim × 2 bytes = 64 KiB/token
```
| Total ctx-size | KV cache, fp16 | KV cache, q8_0 | KV cache, q4_0 |
|---|---|---|---|
| 262,144 (current) | ~16.0 GiB | ~8.0 GiB | ~4.0 GiB |
| 500,000 | ~30.5 GiB | ~15.3 GiB | ~7.6 GiB |
| **1,000,000 (500k×2, or 1M stretch)** | **~61.0 GiB** | **~30.5 GiB** | **~15.3 GiB** |
(`q8_0` is 8-bit vs. fp16's 16-bit → exactly half; `q4_0` is 4-bit → exactly quarter, per llama.cpp's
own cache-type byte widths.)
### Qwen3-4B-Instruct-2507 (plain GQA transformer, classifier role)
From [`Qwen/Qwen3-4B-Instruct-2507/config.json`](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507/raw/main/config.json)
(already pulled in [`fast-model-choice.md`](fast-model-choice.md)): `num_hidden_layers=36` — every
layer is standard attention here (no hybrid split), `num_key_value_heads=8`, `head_dim=128`.
```
36 layers × 2 (K+V) × 8 kv_heads × 128 head_dim × 2 bytes = 144 KiB/token
```
The classifier's real transcript ceiling is ~40-50K tokens (qwen-code's own
`MAX_TRANSCRIPT_MESSAGES=40` × `MAX_HISTORICAL_ACTION_CHARS=4000`, per `fast-model-choice.md` §"what
actually shipped") — nowhere near 500k/1M, so the classifier does **not** need to grow for this
roadmap; it stays exactly as deployed today, on its own small allocation. Per-token cost is included
here only because it feeds the "does the classifier's dedicated GPU need to change" question in §6.
---
## 4. Total VRAM budget: 500k × 2 parallel, and the 1M stretch
Weights: `Qwen3.8-27B-UD-Q4_K_XL.gguf` is **17.6 GB**, confirmed directly from the
[unsloth/Qwen3.8-27B-GGUF file tree](https://huggingface.co/unsloth/Qwen3.8-27B-GGUF/tree/main)
(already verified in `qwen3.8-27b-quant.md`).
Per §2, both "500k × 2 parallel" and "1M stretch" require `--ctx-size 1000000` — same KV budget:
| KV precision | KV cache | + weights (17.6 GB) | + est. compute-buffer/runtime overhead* | **Realistic total** |
|---|---|---|---|---|
| fp16 (default) | 61.0 GiB | 78.6 GiB | +3-6 GiB | **~82-85 GB** |
| q8_0 (proven in this stack today) | 30.5 GiB | 48.1 GiB | +3-6 GiB | **~51-54 GB** |
| q4_0 (proven in this stack today, on the classifier) | 15.3 GiB | 32.9 GiB | +3-6 GiB | **~36-39 GB** |
\* *Estimate, not a cited figure* — llama.cpp's flash-attention compute buffer scales closer to
linear than the unfused-attention path, per this repo's own measured note in `docker-compose.yml`'s
`qwen-classifier` comment (unfused attention buffers ballooned unexpectedly at 65536 ctx; flash-attn
fixed it). `--flash-attn on` is already the deployed default for the main model, so the linear-ish
regime applies, but no primary source gives an exact formula for this buffer size at 1M context — the
+3-6 GiB band is this doc's estimate based on the ratio observed in that in-repo incident, not a
llama.cpp-documented number. Budget for the high end of that range when sizing hardware.
**Bottom line:** at `q4_0` KV (the most aggressive, already-proven-in-this-repo tier), 500k×2 /
1M needs **~36-39 GB** total VRAM for the 27B model alone. That does not fit one 32GB card at any
precision — it needs at least two 32GB-class cards, or one ≥40GB card. At `q8_0` (the precision this
repo already runs in production for quality reasons), budget **~51-54 GB** — two 32GB cards (64GB
pooled) clears this with room to spare; a single 48GB-class card would not.
(§11 below extends this table to higher weight-quant tiers — Q6_K_XL, Q8_0, BF16 — for users who want
better output quality than `Q4_K_XL`, and to a Flash-Next alternative architecture; see §11.6-§11.7.)
---
## 5. CPU/motherboard: which Threadripper generations give PCIe 4.0, and how many lanes for GPUs
AMD's own product/chipset pages, cross-checked against the launch reviews that quote them directly:
| Platform | Socket | PCIe generation | Total CPU-provided lanes |
|---|---|---|---|
| Threadripper 1000/2000 series ("1920X", "2950X", etc.) | **TR4** | **PCIe 3.0 only** | 60-64 |
| Threadripper 3000 series (3960X/3970X/3990X) | **sTRX4** | **PCIe 4.0** | 64 |
| Threadripper 7000 series (non-PRO) | sTR5 | PCIe 5.0 (48 lanes) + PCIe 4.0 (24-32 lanes) | ~72-80 |
| Threadripper PRO 3000WX/5000WX | sWRX8 | PCIe 4.0 | **128** |
| Threadripper PRO 7000WX | sTR5 (WRX90) | PCIe 5.0 (128 lanes) + a few PCIe 3.0 | **128** |
Sources: [AMD chipsets product page](https://www.amd.com/en/products/processors/chipsets.html)
(sWRX8/socket listing), corroborated by
[Tom's Hardware — Threadripper 3960X/3970X, sTRX4/TRX40 launch coverage](https://www.tomshardware.com/news/amd-unveils-threadripper-3960x-and-3970x-ryzen-9-3950x-details-and-athlon-3000g/2)
(*"the 3rd Gen TR CPUs carry the same 64 PCIe lanes but double bandwidth by moving from Gen 3.0 to
Gen 4.0"* — explicit confirmation TR4/1000-2000-series is PCIe 3.0 while sTRX4/3000-series is PCIe
4.0), [PCWorld — Threadripper PRO launch](https://www.pcworld.com/article/393181/amd-threadripper-pro-has-64-cores-128-pcie-lanes-and-8-channel-memory-support.html)
(*"128 PCIe lanes"* for PRO).
**This directly matters for the user's plan.** "An older Threadripper... for more PCIe lanes" is
ambiguous between two real, very different chips:
- **TR4 (1000/2000 series)** — cheapest used option, but **PCIe 3.0** — does not meet the user's own
stated PCIe 4.0 requirement, and PCIe 3.0 x8 per GPU roughly halves inter-GPU/host transfer
bandwidth (matters more for training/tensor-parallel than for llama.cpp's inference-time layer
splitting, but still a real downgrade vs. the R9700's native PCIe 5.0).
- **sTRX4 (3000 series, non-PRO)** — the correct "older Threadripper with PCIe 4.0" target: 64 lanes,
4-5 years old, real used-market availability, no PRO price premium.
- **Threadripper PRO (3000WX/5000WX)** doubles the lane count to 128 but at meaningfully higher used
cost (workstation-tier, lower volume, sWRX8 boards are pricier than sTRX4/TRX40 boards) — worth it
only if 6 full-bandwidth (x16) GPU slots are actually needed; at x8-per-card (adequate for inference)
64 lanes already covers 6 GPUs with lanes to spare for NVMe/chipset.
**Lane budget for 6 GPUs on sTRX4 (64 lanes), estimated (no vendor spec gives a topology this
specific — treat this bullet as an estimate):** typical sTRX4 boards reserve ~4 lanes for the
chipset uplink and commonly wire 1-2 M.2 slots directly to the CPU (4 lanes each) — so realistic
GPU-available lanes land around 44-52 of the 64, i.e. **6 GPUs at x8 electrical each (48 lanes) is
plausible but board-model-dependent**; x16-each for 6 cards is not possible on 64 lanes regardless of
board. x8 electrical is not a meaningful inference-speed penalty for llama.cpp (weights are loaded
once; the ongoing per-token traffic across PCIe is small compared to compute), so this is an
acceptable tradeoff, not a real bottleneck for this workload.
---
## 6. Power budget vs. the ~200W / one spare 8-pin headroom
Official/vendor TDPs:
| Card | TDP | Source |
|---|---|---|
| GTX 1080 (owned) | 180W, one 8-pin | [confirmed 180W, PCIe 3.0 x16, 1× 8-pin](https://buildmyserver.com/products/zotac-nvidia-geforce-gtx-1080-8gb-gddr5-180w-pcie-3-0-x16-double-wide-gpu) — spec matches NVIDIA's own launch figures reported across multiple outlets incl. Tom's Hardware |
| RTX 2080 (owned) | 215W | Cross-checked across gpuzoo/cputronic/notebookcheck spec pages, consistent at 215W |
| GT 710 (owned) | ~19W, **no external power connector** (slot power only) | [MSI/EVGA/Zotac GT 710 spec pages](https://www.msi.com/Graphics-Card/GT-710-1GD5-LP/Specification) |
| RTX 3060 12GB (candidate purchase) | 170W, one 8-pin | [NVIDIA-confirmed 170W TDP, one 8-pin connector](https://www.lowyat.net/2021/232659/nvidia-geforce-rtx-3060-specifications-now-official-includes-3584-cuda-cores-and-170w-tdp/) |
| RTX 3090 24GB (candidate purchase) | 350W, two 8-pin, [NVIDIA's own RTX 3090 product page](https://www.nvidia.com/en-us/geforce/graphics-cards/30-series/rtx-3090/) lists 350W and a 750W PSU minimum | NVIDIA official |
| R9700 32GB (already deployed / "more of the same") | 300W (per this repo's `server-planing.md`, consistent with AMD's own R9700 product page framing it as a 300W-class card) | in-repo prior research |
**Against the stated ~200W / one spare 8-pin budget:**
- Adding **one RTX 3060 12GB** (170W, one 8-pin) is the *only* candidate in this list that fits the
stated headroom as-is — it uses the one spare connector and stays under 200W.
- Adding the already-owned **GTX 1080** (180W) as the classifier's dedicated card also just barely
fits (180W ≤ 200W, one 8-pin) — this is a genuinely free option since the card is already owned and
its power draw is within budget, unlike every purchase candidate below.
- Adding the already-owned **RTX 2080** (215W) **exceeds** the stated 200W headroom by 15W — technically
over budget on paper, though real-world draw is usually a bit under rated TDP; flag it as marginal,
not safely fitting.
- Adding a **second R9700** (300W) or an **RTX 3090** (350W, needs two 8-pin — the user has only one
spare) both blow well past the current power budget on both watts and connector count.
- **The GT 710 draws no meaningful power (~19W, no PCIe power connector at all)** — it is free from a
power-budget standpoint regardless of what else is added.
**PSU upgrade trigger:** the very first stage that adds *any* GPU beyond a GTX 1080-class card (180W,
one 8-pin) or an RTX 3060 12GB (170W, one 8-pin) exhausts the stated headroom. Any stage that reaches
for a second 32GB-class card (R9700 or equivalent) or any 300W+ card **requires a PSU upgrade before
that stage**, not after — see the roadmap table in §7 for exactly which stage that is.
---
## 7. Mixed-GPU feasibility: ROCm + CUDA, and is the GT 710 usable at all
**ROCm and CUDA are different llama.cpp builds, but that's exactly the pattern already in this
repo.** `ghcr.io/ggml-org/llama.cpp` publishes both `server-rocm` and `server-cuda` as separate,
independently-built image tags (confirmed present on the [ggml-org container registry](https://github.com/orgs/ggml-org/packages/container/llama.cpp)
and documented in [`docs/docker.md`](https://raw.githubusercontent.com/ggml-org/llama.cpp/master/docs/docker.md)
*"server-cuda: Same as `server` but compiled with CUDA support"*, *"server-rocm: Same as `server`
but compiled with ROCm support"*). You cannot mix backends inside one process/container, but you
**can** run one `server-rocm` container pinned to the R9700 and a separate `server-cuda` container
pinned to an NVIDIA card, simultaneously, on the same host — this is architecturally identical to
today's `llama-server` + `qwen-classifier` two-container split in `docker-compose.yml`, just with a
different image tag for the NVIDIA-backed service and NVIDIA's container runtime (`nvidia-container-toolkit`
+ `--gpus` / device reservation, the CUDA-world equivalent of this repo's `/dev/kfd`+`/dev/dri`+
numeric-GID ROCm pattern documented in
[`rocm-gpu-pin-and-render-group.md`](rocm-gpu-pin-and-render-group.md)). None of that doc's ROCm-specific
findings (the `GPU_MAX_HW_QUEUES=1` MES firmware workaround, the numeric-GID `group_add` fix) apply to
an NVIDIA/CUDA container — those are ROCm-stack-specific bugs, not general multi-GPU-container issues.
**Is this an implicit AMD→NVIDIA rebuild, or additive?** Worth surfacing explicitly since the two
source plans conflict on this: `server-planing.md` is an AMD-only, ROCm-only 4×R9700 plan. This
ticket's plan is **additive/mixed** — keep the R9700 running the main model under ROCm, and bolt on
NVIDIA cards under CUDA for secondary roles (classifier, or a second inference GPU for the big model
if going the "more of the same type" route means buying NVIDIA instead of more R9700s). Both are
internally consistent, but they are different end-states — flag this choice back to the user rather
than assuming one.
**Splitting the *main* 27B model itself across mixed AMD+NVIDIA silicon in one process is not
possible** — llama.cpp's multi-GPU tensor-split only works within a single backend build. To use
both an R9700 and an NVIDIA card for the *same* model's layers, all the compute-hosting cards need to
be the same backend (all-ROCm or all-CUDA) in that one process. This is why §5's roadmap treats "add
GPU capacity to the main model" and "add a GPU for the classifier" as separable purchases with
different backend constraints, not a single mixed pool.
**Is the GT 710 usable for anything in this pipeline? No.** Reasoning:
- 1GB VRAM cannot hold any meaningful fraction of either model's weights (17.6 GB / 2.4-4.3 GB) —
even a handful of transformer layers at Q4 quantization exceeds 1GB.
- It's Kepler-generation silicon (192 CUDA cores, no tensor cores) — llama.cpp's CUDA backend
technically supports pre-Turing cards, but at this VRAM size there's nothing to usefully offload.
- It draws power from the PCIe slot only, no external connector — genuinely free to keep installed.
- **Plausible actual use: dedicate it as the box's display-output card**, so every compute-capable
GPU (R9700, and whichever NVIDIA cards get added) can be fully headless/compute-only with none of
their VRAM or a display output tied up driving a monitor — a real, if minor, use for it. This is
this doc's own inference from the spec facts above, not a claim found in any primary source.
---
## 8. GPU market pricing vs. the $20-30/GB assumption
| Card | VRAM | Backend | Current used-market price (estimate — see caveat) | $/GB |
|---|---|---|---|---|
| RTX 3060 12GB | 12GB | CUDA | ~$240-300 used (eBay listings, [gpupoet.com tracker](https://gpupoet.com/gpu/shop/nvidia-geforce-rtx-3060): *"from $239"*, [eBay live listings](https://www.ebay.com/shop/rtx-3060-12gb) averaging ~$488 asking but with a $239 floor) | **~$20-25/GB** — matches the stated assumption |
| RTX 3090 24GB | 24GB | CUDA | ~$1,010-1,050 used ([bestvaluegpu.com Sep 2026 tracker](https://bestvaluegpu.com/history/new-and-used-rtx-3090-price-history-and-specs/), [xda-developers coverage](https://www.xda-developers.com/used-rtx-3090-still-best-for-local-ai-in-value/)) | **~$42-44/GB** — well above the stated assumption |
| R9700 32GB ("more of the same type") | 32GB | ROCm | **New only — $1,299 MSRP**, street price $1,400-1,585 as of this research ([overclock3d](https://overclock3d.net/news/gpu-displays/amd-unveils-its-1299-radeon-ai-pro-r9700-32gb-workstation-gpu/), [pricehistory.app tracker](https://pricehistory.app/p/powercolor-amd-radeon-ai-pro-r9700-32gb-BFcRhGIm)) — too recent a release (2026) for a used market to exist yet | **~$41-50/GB, and not a used-market price at all** |
**Caveat on all three price figures:** these are live marketplace asking-price snapshots pulled via
web search on 2026-09-11, not sold-price data or a vendor spec sheet — treat as directional, not
exact. eBay asking prices in particular run above realized sale prices.
**Correction to the user's stated assumption:** $20-30/GB is a good estimate specifically for
**last-generation mainstream used cards** (RTX 3060 12GB fits it almost exactly) but **not** for
high-VRAM flagship cards like the RTX 3090 (~1.5-2× that rate) or for "more of the same type" R9700
units, which aren't used-market at all yet and sit even higher per GB than the 3090. If the plan is
"cheapest path to more VRAM," multiple RTX 3060 12GB cards (or similar mid-tier used cards) beat one
RTX 3090 on $/GB, at the cost of needing more PCIe slots and more total wattage/connectors to reach
the same aggregate VRAM — which is exactly the tradeoff the Threadripper lane-count plan in §5 is
for.
---
## 9. Step-by-step roadmap
All "resulting max context" figures assume `--parallel 2` and the KV precision stated; per §2, the
`--ctx-size` value shown is the *total* (pre-division) value to pass to llama-server.
| Stage | Hardware change | Est. cost | Backend | Usable VRAM (main-model pool) | Max context @ parallel=2 (`q4_0` KV) | PSU upgrade triggered? |
|---|---|---|---|---|---|---|
| **0 (current)** | 1× R9700 32GB, in production | $0 | ROCm | 32GB (shared with classifier) | ~131K/slot today at `q8_0` KV (262144 total ÷ 2) | No |
| **1 — classifier isolation** | Move classifier onto the already-owned **GTX 1080** (180W, own container, `server-cuda`), freeing the R9700 entirely for the main model. Matches the existing dual-model pattern qwen-code's own docs describe (§10) and this repo's `qwen-classifier` service already implements, just on separate silicon instead of a shared card. | $0 (already owned) | ROCm (main) + CUDA (classifier) | R9700's full 32GB now available to the main model alone | ~262K/slot @ `q8_0` (unchanged ctx-size, no more classifier contention) | **No** — 180W GTX 1080 fits the stated ~200W/one-8-pin headroom |
| **2 — second big-model GPU** | Add **one more 32GB-class card** for the main model. Cheapest correct-backend option: a second R9700 (~$1,300-1,585 new, ROCm, same backend as the first — required if tensor-splitting one model across two cards) | ~$1,300-1,585 | ROCm | 64GB pooled | `--ctx-size 500000 --parallel 1` fits at `q4_0` (~33GB) or `q8_0` (~48GB, tight but fits in 64GB) — **not yet 500k×2** | **Yes** — 300W card, no spare 8-pin left after stage 1 |
| **3 — reach 500k × 2 / 1M stretch** | No further hardware if stage 2's 64GB pool is used with `--cache-type-k/v q4_0`: `--ctx-size 1000000 --parallel 2` needs ~33-39GB (§4), fits inside 64GB with real headroom for the compute buffer. If `q8_0` KV is required instead (this repo's current quality bar for the main model), the ~51-54GB need is tight-to-marginal on 64GB — a **third** 32GB card (~96GB pool) removes the risk. | $0 (reuses stage 2) or +$1,300-1,585 for a 3rd card if `q8_0` KV is required | ROCm | 64GB (q4_0 case) or 96GB (q8_0 case) | **500k×2 parallel achieved**, and the 1M stretch goal is the *same config* with `--parallel 1` instead of 2 (§2) | Already upgraded at stage 2 |
| **4 — optional CPU/lane platform swap** | Only needed if the plan is to keep scaling past 2-3 big cards, or to add several small used cards (RTX 3060 12GB) for extra headroom/throughput rather than raw ctx-size. Swap to **non-PRO Threadripper 3000-series (sTRX4)** — 64 PCIe 4.0 lanes, ~x8-per-slot for up to 6 GPUs (§5). Threadripper PRO 3000WX/5000WX (128 lanes) only if x16-per-card matters or 6+ full-bandwidth slots are wanted. | Used sTRX4 CPU+board: roughly $400-800 combined on the used market (not independently priced in this pass — **estimate**, not cited) | n/a (platform only) | n/a | n/a | Independent of GPU wattage — driven by whatever GPU count/wattage stage 5+ adds |
| **5+ — scale-out via small used cards** | Add RTX 3060 12GB units (~$20-25/GB, the assumption that actually holds, §8) instead of more 32GB flagship cards, once lane count (stage 4) supports it — useful for extra parallel slots / throughput beyond the 500k×2 target rather than for raising ctx-size further (500k×2/1M is already met at stage 3). | ~$240-300/card | CUDA (separate container per §6) | +12GB pooled per card, but on a *different backend* from the ROCm main model — usable for extra classifier/small-model capacity or a separate CUDA-backend llama-server instance, not as additional tensor-split VRAM for the ROCm main model | Unchanged for the main model; adds parallel capacity elsewhere | Yes, cumulative — each additional 170W card needs PSU headroom stage 2 already consumed |
**Where the existing dual-model pattern sits in this roadmap:** it's stage 1, and it's free. The
qwen-code docs pattern (main model + a small, always-resident, non-thinking fast/classifier model —
see §10) is already implemented in this repo; the only roadmap-relevant change is *which GPU* the
classifier sits on, moving it off the R9700 entirely onto an already-owned NVIDIA card frees the
R9700's full 32GB for the 500k×2/1M push instead of splitting it with the classifier as happens
today.
### 9.1 Upgrade path, as diagrams
Diagram form of the same §9 table and §11.9's dense-vs-Flash-Next call — nothing new is claimed here,
this is a visual index back into the cited sections above.
**Stage-by-stage hardware path** (PSU-upgrade triggers and target reached called out inline):
```mermaid
flowchart TD
S0["Stage 0 — today<br/>1x R9700 32GB, ROCm<br/>classifier shares the card<br/>$0"]
S1["Stage 1 — classifier isolation<br/>+ GTX 1080 (owned, 180W, CUDA)<br/>R9700 freed for main model<br/>$0 · PSU OK (180W fits ~200W headroom)"]
S2["Stage 2 — 2nd big-model GPU<br/>+1x R9700 32GB (ROCm)<br/>64GB pooled<br/>~$1,300-1,585 · PSU UPGRADE REQUIRED (300W, no 8-pin left)"]
S3q4["Stage 3a — q4_0 KV<br/>--ctx-size 1,000,000 --parallel 2<br/>~33-39GB, fits in 64GB<br/>$0 (reuses stage 2)"]
S3q8["Stage 3b — q8_0 KV (current prod quality)<br/>~51-54GB, tight on 64GB<br/>+1x R9700 -> 96GB removes risk<br/>+~$1,300-1,585"]
TARGET(["500k x2 parallel reached<br/>= 1M stretch goal, same VRAM<br/>(--parallel 1 vs 2 is a config flag, §2)"])
S4["Stage 4 — platform swap (optional)<br/>sTRX4 Threadripper 3000, 64 PCIe4 lanes<br/>only needed past 2-3 big cards<br/>~$400-800 (estimate, §9)"]
S5["Stage 5+ — scale out<br/>+RTX 3060 12GB cards (CUDA, separate backend)<br/>extra parallel/throughput, not more ctx-size<br/>~$240-300/card · PSU upgrade each card"]
S0 --> S1 --> S2
S2 --> S3q4 --> TARGET
S2 --> S3q8 --> TARGET
TARGET -.->|"only if scaling past this"| S4 --> S5
style TARGET fill:#2e7d32,color:#fff,stroke:#1b5e20
style S2 fill:#8a5a00,color:#fff,stroke:#5c3d00
style S5 fill:#8a5a00,color:#fff,stroke:#5c3d00
```
**Model choice, and the one open question that could change it** (§11.9):
```mermaid
flowchart TD
Q{"Goal: 500k-1M ctx<br/>within a $20-30/GB VRAM budget?"}
D["Dense Qwen3.8-27B<br/>17.6-54.7GB weights (Q4_K_XL-BF16)<br/>reaches 500k x2 on 2-3 cards,<br/>500k x4 on 2-6 cards depending on quant<br/>(§11.7 tables)"]
F{"Try --n-cpu-moe:<br/>offload MoE experts to system RAM?<br/>(untested for this model, §11.8)"}
FBAD["Flash-Next, all-GPU weights<br/>111-354GB just for weights<br/>needs 4-13 cards before any KV cost<br/>NOT recommended at this budget (§11.9)"]
FGOOD["Flash-Next, experts in system RAM<br/>GPU VRAM could shrink a lot<br/>2.67x cheaper KV/token becomes relevant<br/>UNVERIFIED — prototype on real server first"]
CAVEAT["+ real caveat either way:<br/>PR #27742 flags unverified conv branch,<br/>3% QSA divergence, prefill-pos-0-only PLE<br/>(§11.1) — dense model carries no such flag"]
Q --> D
Q -->|"considering Flash-Next instead"| F
F -->|"works well"| FGOOD
F -->|"doesn't help / untested"| FBAD
FGOOD --> CAVEAT
FBAD --> CAVEAT
style D fill:#2e7d32,color:#fff,stroke:#1b5e20
style FBAD fill:#8a1c1c,color:#fff,stroke:#5c1212
style FGOOD fill:#8a5a00,color:#fff,stroke:#5c3d00
```
---
## 10. Qwen-code's own docs on the fast-model/classifier pattern
Fetched directly per the user's link:
[qwenlm.github.io/qwen-code-docs/en/users/overview/](https://qwenlm.github.io/qwen-code-docs/en/users/overview/)
**the overview page itself does not describe the dual-model/classifier pattern**; it only covers
single-model-provider setup (Alibaba ModelStudio / third-party / custom provider), one model at a
time. The actual fast-model/classifier documentation lives on the **Auto Mode** page instead, which
this repo's own `fast-model-choice.md` already fetched and cited in detail:
[qwenlm.github.io/qwen-code-docs/en/users/features/auto-mode/](https://qwenlm.github.io/qwen-code-docs/en/users/features/auto-mode/) —
summary (see `fast-model-choice.md` §1 for the full quote): a two-stage classifier gate, both stages
using "your configured fast model (`/model --fast`)", Stage 1 a ~300ms `{shouldBlock}`-only check,
Stage 2 a ~3-5s chain-of-thought review that only runs on a Stage-1 block. Nothing in either page
gives a recommended *context size* or *model size* for the fast model beyond what's implied by that
latency budget — this repo's own prior research (`fast-model-choice.md`) derived the actual context
requirement from qwen-code's source code instead (`packages/core/src/permissions/classifier-transcript.ts`),
since the docs pages don't state one. No new information changes that prior doc's conclusion; this
section exists to confirm the overview page was checked directly as instructed and doesn't contradict
or add to it.
---
## 11. Alternative: Qwen3.8-Flash-Next (MoE, hybrid attention)
The user also wants to weigh switching (or adding) **Qwen3.8-Flash-Next** — a 125B-total/6B-active MoE
with a hybrid recurrent-attention architecture — against staying on dense Qwen3.8-27B, and separately
wants this section to cover **going up in weight quant** (Q4_K_XL → Q6_K_XL → Q8_0 → BF16/fp16) for
*both* models, not just Q4. Feasibility first, since it gates everything else.
### 11.1 Feasibility verdict: supported, but immature — read before trusting any number below
Checked directly against the primary sources the task named:
- **llama.cpp mainline support exists.** [PR #27742](https://github.com/ggml-org/llama.cpp/pull/27742)
("model: add Qwen3.8-Flash-Next (qwen4exp)") was **merged into `master` on 2026-08-27** by ngxson.
It adds the full architecture: Gated DeltaNet layers (sigmoid-gated linear attention), QSA
("Qwen Sparse Attention", operating at micro-block granularity), hyper-connections, and the PLE
n-gram embedding table. `llama.cpp`'s own docs list CPU/CUDA/Metal/ROCm as supported backends for
it — this is not a CUDA-only feature.
- **This repo's pinned image is a floating tag, not a version pin.** `docker-compose.yml` runs
`ghcr.io/ggml-org/llama.cpp:server-rocm` with no date/digest suffix — a rolling "latest ROCm server
build" tag, not a release version. The merge is from 2026-08-27, and today is 2026-09-11 (~2 weeks
later), so a **fresh pull** of `server-rocm` should include it — but whatever image is already
cached/running on the R9700 box may predate the merge. **Action before touching this model on the
server: `docker compose pull llama-server` and check the startup log's build/commit banner is dated
on/after 2026-08-27**, not just "the tag says server-rocm."
- **Real, primary-source-flagged immaturity — this is the part that should temper enthusiasm.** The
PR's own description/review discussion states: *"The conv branch itself is still numerically
unverified because the fixture zeroes its weights"*; QSA sparse attention *"diverges on 3 percent of
positions"* above its budget threshold; the PLE depthwise convolution *"is exact only for a prefill
that starts at position 0"* (i.e. correctness is not guaranteed once `--cache-reuse`/prompt-caching
is in play — a flag this repo already turns on for the dense model per the latest commit). None of
that is disqualifying, but it is a primary-source admission that this is a fresh, not-fully-verified
implementation, not a mature, widely-battle-tested one like the dense Qwen3.8-27B path.
- **Multi-slot serving needs an explicit new flag.** The same PR states: *"`set_input_qsa` asserted
`n_stream == 1`, so llama-server could not serve this model with more than one slot unless `-kvu`
was passed."* Per the server README (§2), `--kv-unified`/`-kvu` defaults to enabled **only when slot
count is auto** (`-1`). This repo's compose file sets `--parallel ${LLAMA_PARALLEL:-2}` **explicitly**
(not auto) — so adopting Flash-Next with `--parallel` > 1 requires **adding `--kv-unified` (or
`-kvu`) to the launch flags**, a real deploy-time change, not something that "just works" by copying
today's flag set onto a new model file.
**Verdict: yes, runnable** on this repo's backend (ROCm, mainline, no dev branch needed) as long as the
image is pulled after 2026-08-27 and `-kvu` is added for multi-slot use — but treat it as
**usable-with-caution**, not a drop-in swap, given the PR author's own unresolved-correctness notes.
### 11.2 Architecture, verified against `config.json` directly
Fetched from `Qwen/Qwen3.8-Flash-Next`'s `config.json` (unsloth's GGUF repo repackages the same base
model): `num_hidden_layers=48`, `hidden_size=2560`, `num_attention_heads=24`, `num_key_value_heads=2`,
`head_dim=256`, `max_position_embeddings=262144` (same native/extensible-to-1M framing as the dense
model — same YaRN quality caveat from §3 applies here too, unverified past native length), `num_experts=512`,
`num_experts_per_tok=10`, and the linear-attention head config: `linear_num_key_heads=16`,
`linear_num_value_heads=48`, `linear_key_head_dim=128`, `linear_value_head_dim=128`.
Layer pattern (confirmed both from the model card's own description and `config.json`'s
`full_attention_interval=4`): every 4th layer is full/QSA attention, the other 3 are Gated DeltaNet —
**12 of 48 layers grow a real KV cache; the other 36 have a fixed-size recurrent state that does not
grow with context length.** (24% full-attention layers vs. the dense model's 16-of-64 = 25% — similar
ratio, but the *absolute* per-layer KV cost differs because `num_key_value_heads` is 2 here vs. 4 on
the dense model — see below.)
### 11.3 Per-token growing-KV-cache cost
```
12 full-attention layers × 2 (K+V) × 2 kv_heads × 256 head_dim × 2 bytes (fp16) = 24 KiB/token
```
| Total ctx-size | KV cache, fp16 | KV cache, q8_0 | KV cache, q4_0 |
|---|---|---|---|
| 262,144 (native) | ~6.0 GiB | ~3.0 GiB | ~1.5 GiB |
| 500,000 | ~11.4 GiB | ~5.7 GiB | ~2.9 GiB |
| **1,000,000 (500k×2, or 1M stretch)** | **~22.9 GiB** | **~11.4 GiB** | **~5.7 GiB** |
| **2,000,000 (500k×4)** | **~45.8 GiB** | **~22.9 GiB** | **~11.4 GiB** |
`--cache-type-k/v` are the same generic llama.cpp KV-cache-quantization flags used elsewhere in this
doc; nothing in the PR or the server README suggests they're handled differently for the 12
full-attention layers of a hybrid model — they quantize the same growing K/V buffers as on a plain
transformer. (No primary source explicitly confirms this for *this* architecture specifically — flagged
as a reasonable extrapolation, not a directly-cited fact, same caveat class as this doc's other
estimates.)
### 11.4 Fixed (non-growing) recurrent state — Gated DeltaNet layers
The 36 Gated DeltaNet layers each keep a fixed-size recurrent state (an outer-product-style
key×value matrix per head) that does **not** scale with context length — only with slot/sequence
count. Sized from `config.json`'s linear-attention head params:
```
36 layers × linear_num_value_heads(48) × linear_key_head_dim(128) × linear_value_head_dim(128) × 4 bytes (fp32 state)
≈ 36 × 48 × 128 × 128 × 4 bytes ≈ 108 MiB per slot
```
This is **this doc's own derivation from the published head-dimension params, not a value pulled
directly from llama.cpp source or docs** — the PR text confirms the state exists per-stream/per-slot
but doesn't publish an exact byte formula, so treat the ~108 MiB/slot figure as an estimate, medium
confidence. Even at 4 parallel slots that's under half a gigabyte — **negligible** next to both the
growing KV cache (GBs) and the weights (tens to hundreds of GB) computed below. The headline
implication holds regardless of the exact multiplier: Flash-Next's "big memory line item" is the MoE
weights, not the attention state of any kind.
### 11.5 Magnitude vs. the dense model — how much cheaper is KV, really
At the same total ctx-size, Flash-Next's growing KV cache is **24 KiB/token vs. the dense model's
64 KiB/token — 2.67× smaller**, i.e. Flash-Next's KV budget is **37.5%** of the dense model's at
identical context length. This is a real, significant win *for the KV-cache line item specifically*
but see §11.9: it's a much smaller slice of a much bigger total, because the weights move the other
way by a far larger factor.
### 11.6 Weight sizes — verified from each unsloth GGUF repo's actual file listing
Fetched directly from the HF file trees (not estimated from ratios), current as of this research pass:
| Quant tier | Qwen3.8-27B (dense) | Qwen3.8-Flash-Next (MoE) |
|---|---|---|
| Q4_K_XL (`UD-Q4_K_XL`) | **17.6 GB** (existing baseline) | **111.4 GB** (4 parts: 10.9MB + 49.9GB + 49.4GB + 12.1GB) |
| Q6_K_XL (`UD-Q6_K_XL`) | **25.3 GB** | **169 GB** (6 parts) |
| Q8_0 | **29 GB** | **188 GB** (6 parts) |
| BF16/fp16 | **54.67 GB** (50GB + 4.67GB, 2 parts) | **354 GB** (8 parts) |
Sources: [unsloth/Qwen3.8-27B-GGUF file tree](https://huggingface.co/unsloth/Qwen3.8-27B-GGUF/tree/main)
and its `BF16/` subfolder; [unsloth/Qwen3.8-Flash-Next-GGUF file tree](https://huggingface.co/unsloth/Qwen3.8-Flash-Next-GGUF/tree/main)
and its `UD-Q4_K_XL/`, `UD-Q6_K_XL/`, `Q8_0/`, `BF16/` subfolders (per-file sizes summed). The
preliminary Q8_0 figure floated before this research pass (~192GB) was slightly high — the real
listing sums to **188 GB**; everything else in the preliminary list was accurate to within rounding.
**The weight-quant axis and the KV-cache-quant axis are independent knobs.** Raising weight quality
(Q4_K_XL → BF16) does not require raising `--cache-type-k/v` — the two flags are unrelated, and this
repo already proves that pattern works (`q8_0` KV cache is deployed today against `Q4_K_XL` weights).
A user chasing **maximum output quality** can run e.g. **BF16 weights + `q4_0` KV cache** — full-precision
weights for quality, still-compressed KV for context budget — or any other combination in the tables
below; nothing about picking a higher weight quant forces a matching KV precision.
### 11.7 Total VRAM: does it fit, across quant tiers and both parallelism targets
All totals = weights + growing KV cache + an estimated **+3-6 GB** compute-buffer/runtime overhead
(same estimate band as §4, carried over — not re-derived for this architecture; flagged medium
confidence there too). "Cards" = ceil(total ÷ 32GB), i.e. how many R9700-class 32GB cards it takes.
#### Dense Qwen3.8-27B — 500k × 2 parallel / 1M stretch (`--ctx-size 1,000,000`)
| Weight quant | fp16 KV → total (cards) | q8_0 KV → total (cards) | q4_0 KV → total (cards) |
|---|---|---|---|
| Q4_K_XL (17.6GB) | ~79-85GB (**3**) | ~48-54GB (**2**) | ~33-39GB (**2**) |
| Q6_K_XL (25.3GB) | ~89-92GB (**3**) | ~59-62GB (**2**, tight) | ~44-47GB (**2**) |
| Q8_0 (29GB) | ~93-96GB (**3**, edge) | ~63-66GB (**2-3**, edge) | ~47-50GB (**2**) |
| BF16 (54.67GB) | ~119-122GB (**4**) | ~88-91GB (**3**) | ~73-76GB (**3**) |
#### Dense Qwen3.8-27B — 500k × 4 parallel (`--ctx-size 2,000,000`)
| Weight quant | fp16 KV → total (cards) | q8_0 KV → total (cards) | q4_0 KV → total (cards) |
|---|---|---|---|
| Q4_K_XL (17.6GB) | ~143-146GB (**5**) | ~82-85GB (**3**) | ~51-54GB (**2**) |
| Q6_K_XL (25.3GB) | ~150-153GB (**5**) | ~89-92GB (**3**) | ~59-62GB (**2**, tight) |
| Q8_0 (29GB) | ~154-157GB (**5**) | ~93-96GB (**3**, edge) | ~63-66GB (**2-3**, edge) |
| BF16 (54.67GB) | ~180-183GB (**6**) | ~119-122GB (**4**) | ~88-91GB (**3**) |
#### Qwen3.8-Flash-Next — 500k × 2 parallel / 1M stretch (`--ctx-size 1,000,000`)
| Weight quant | fp16 KV → total (cards) | q8_0 KV → total (cards) | q4_0 KV → total (cards) |
|---|---|---|---|
| UD-Q4_K_XL (111.4GB) | ~137-140GB (**5**) | ~126-129GB (**4**, edge) | ~120-123GB (**4**) |
| UD-Q6_K_XL (169GB) | ~195-198GB (**7**) | ~183-186GB (**6**) | ~178-181GB (**6**) |
| Q8_0 (188GB) | ~214-217GB (**7**) | ~202-205GB (**7**) | ~197-200GB (**7**) |
| BF16 (354GB) | ~357-360GB (**12**) | ~357-360GB (**12**) | ~357-360GB (**12**) |
#### Qwen3.8-Flash-Next — 500k × 4 parallel (`--ctx-size 2,000,000`)
| Weight quant | fp16 KV → total (cards) | q8_0 KV → total (cards) | q4_0 KV → total (cards) |
|---|---|---|---|
| UD-Q4_K_XL (111.4GB) | ~160-163GB (**6**) | ~137-140GB (**5**) | ~126-129GB (**4**, edge) |
| UD-Q6_K_XL (169GB) | ~218-221GB (**7**) | ~195-198GB (**7**) | ~183-186GB (**6**) |
| Q8_0 (188GB) | ~234-237GB (**8**) | ~211-214GB (**7**) | ~199-202GB (**7**) |
| BF16 (354GB) | ~397-400GB (**13**) | ~377-380GB (**12**) | ~366-369GB (**12**) |
(Flash-Next's KV precision barely moves the total at any weight quant above `UD-Q6_K_XL` — the weights
so dominate the budget that KV quantization stops mattering for the "how many cards" question. This
is the clearest signal in this whole section: for Flash-Next, the weight-quant choice is the entire
hardware-sizing decision; for the dense model, KV precision still matters a lot.)
### 11.8 CPU MoE-expert offload — the one lever that could change this calculus
Flash-Next is a 512-expert/10-active-per-token MoE, and llama.cpp has a purpose-built flag for exactly
this shape of model, confirmed directly from the server README: **`--n-cpu-moe`** — *"keep the Mixture
of Experts (MoE) weights of the first N layers in the CPU"* — plus the more general
**`--override-tensor`** (*"override tensor buffer type"*, pattern-matched by tensor name) that the same
flag is built on top of. Both are generic, architecture-agnostic llama.cpp mechanisms (they match on
tensor name patterns, not model type), so there's no reason to expect them not to apply to Flash-Next's
MoE tensors specifically — but this pass found **no primary source that has actually tested
`--n-cpu-moe` against this specific qwen4exp architecture**, so treat "it works here" as plausible,
not confirmed.
If it does work as expected, this changes the whole weight-VRAM picture in §11.7: the ~90-95% of
Flash-Next's weight footprint that's MoE expert tensors could live in system RAM while attention
projections, the shared/non-expert tensors, and the full KV cache stay on GPU — meaning a much smaller
GPU-VRAM number than the "all weights on GPU" tables above, at the cost of PCIe/RAM-bandwidth-bound
inference speed for whichever experts get selected per token (this repo has no benchmark of that
tradeoff, and it's highly system-RAM-bandwidth-dependent, so no number is given here — flagged as an
escape hatch worth prototyping directly on the server, not something this research values responsibly
without a real test run).
### 11.9 Net recommendation: dense Qwen3.8-27B vs. Flash-Next, for this user's stated goal
**Net loss for this user's goal, as things stand — stay on dense Qwen3.8-27B.** Reasoning:
- The user's target (500k×2 or 500k×4, on a $20-30/GB-VRAM budget, GPUs in 32GB increments) is a
**VRAM-budget-constrained** goal, and §11.7 shows Flash-Next's *weights alone* (111-354GB depending
on quant) dwarf the entire dense-model total-VRAM figure from §4/§11.7 (33-183GB depending on quant)
at every parallelism target. Flash-Next's much cheaper per-token KV cache (§11.5, real and verified)
is a rounding error next to that weight-size gap — the "2.67× cheaper KV" win doesn't come close to
offsetting a "6-20× larger weight footprint," so at $20-30/GB-VRAM the *dense* model reaches 500k×2
or 500k×4 for a fraction of the card count and dollar cost that Flash-Next needs even at its lowest
usable quant (`UD-Q4_K_XL`, 4-5 cards minimum) — before even factoring in §11.1's immaturity flags.
- The one scenario that could flip this verdict is `--n-cpu-moe` actually working well for this
architecture (§11.8) — if most of those 111-354GB of expert weights can sit in system RAM at
acceptable throughput, Flash-Next's GPU-VRAM number could shrink dramatically and its real KV-cache
advantage would start to matter. That is untested here and shouldn't be assumed; it's the one
concrete next step worth trying on the actual server before ruling Flash-Next out permanently.
- Independent of VRAM: §11.1's primary-source-flagged correctness caveats (unverified conv branch,
3%-divergence QSA, prefill-position-0-only PLE exactness) are a real quality/stability risk on a
production coding-agent stack that dense Qwen3.8-27B simply doesn't carry, since it's been running
in this repo already.
---
## 12. 4-parallel × 500k scenario — all four combinations side by side
Per §2's already-established, cited rule (`n_ctx_per_seq = n_ctx / n_parallel`,
[ggml-org/llama.cpp#11681](https://github.com/ggml-org/llama.cpp/issues/11681)), the same division
applies at 4 slots: **500k tokens on each of 4 parallel slots requires `--ctx-size 2,000,000`**
double the 2-parallel target's `--ctx-size 1,000,000`, for the same reason 500k×2 needed double
262,144. This isn't a new mechanism, just the same formula at `--parallel 4`.
Full per-quant-tier tables for all four combinations are in §11.7 above (dense×2, dense×4, Flash-Next×2,
Flash-Next×4 are each their own table there). Headline comparison at the KV precision already proven
in production in this repo (`q8_0`) and each model's respective current/cheapest-usable weight quant:
| Scenario | `--ctx-size` | Weight quant | q8_0-KV total VRAM | Cards (32GB) |
|---|---|---|---|---|
| Dense × 2 (or 1M stretch) | 1,000,000 | Q4_K_XL (17.6GB, current) | ~48-54GB | **2** |
| Dense × 4 | 2,000,000 | Q4_K_XL (17.6GB, current) | ~82-85GB | **3** |
| Flash-Next × 2 (or 1M stretch) | 1,000,000 | UD-Q4_K_XL (111.4GB, cheapest usable) | ~126-129GB | **4**, edge |
| Flash-Next × 4 | 2,000,000 | UD-Q4_K_XL (111.4GB, cheapest usable) | ~137-140GB | **5** |
**4-parallel × 500k reachability against this repo's existing roadmap stages (§9):**
- **(a) Current 1×R9700 32GB:** none of the four combinations fit — not even dense×2 at any weight/KV
quant (§4's own conclusion, unchanged).
- **(b) The 2-3×R9700 roadmap already proposed in §9 (64-96GB):** covers **dense×2 fully** (stage 3, as
already established) and **dense×4 at `q4_0` KV with Q4_K_XL or Q6_K_XL weights** (~51-62GB, fits in
64-96GB) — but **not** dense×4 at higher weight quants (Q8_0/BF16 need 3-6 cards depending on KV
precision, per §11.7's dense×4 table) and **not any Flash-Next scenario** (minimum is 4 cards/128GB
even at the cheapest usable quant and tightest KV).
- **(c) The full 4-6×R9700 stretch scenario** (`server-planing.md`'s original plan, 128-192GB pooled):
covers **dense×4 at every weight quant up to BF16** (worst case ~91GB at BF16+q4_0, well inside
128GB) and **Flash-Next×2 at `UD-Q4_K_XL`** (126-140GB, fits a 5-card/160GB build, tight on a 4-card/
128GB one) — but **not** Flash-Next×4 at any weight quant above `UD-Q4_K_XL`, and not Flash-Next at
`BF16` under any parallelism (needs 12-13 cards, an entirely different scale of build than anything
in this doc's roadmap).
---
## Sources
- [llama.cpp server README](https://github.com/ggml-org/llama.cpp/blob/master/tools/server/README.md) — `--ctx-size`, `--parallel`, `--cache-type-k/v`, `--kv-unified`, `--cache-reuse`, `--n-cpu-moe`, `--override-tensor` flag definitions
- [ggml-org/llama.cpp#11681](https://github.com/ggml-org/llama.cpp/issues/11681) — real server log proving `n_ctx_per_seq = n_ctx / n_parallel`
- [ggml-org/llama.cpp#27742](https://github.com/ggml-org/llama.cpp/pull/27742) — "model: add Qwen3.8-Flash-Next (qwen4exp)", merged 2026-08-27; architecture details, `n_stream == 1` / `-kvu` multi-slot requirement, and the conv-branch/QSA-divergence/PLE-prefill correctness caveats
- [Qwen/Qwen3.8-27B config.json](https://huggingface.co/Qwen/Qwen3.8-27B/raw/main/config.json)
- [Qwen/Qwen3.8-Flash-Next config.json](https://huggingface.co/Qwen/Qwen3.8-Flash-Next/raw/main/config.json)
- [Qwen/Qwen3-4B-Instruct-2507 config.json](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507/raw/main/config.json)
- [unsloth/Qwen3.8-27B-GGUF file tree](https://huggingface.co/unsloth/Qwen3.8-27B-GGUF/tree/main) — 17.6GB (Q4_K_XL), 25.3GB (Q6_K_XL), 29GB (Q8_0), 54.67GB (BF16) weight sizes
- [unsloth/Qwen3.8-Flash-Next-GGUF file tree](https://huggingface.co/unsloth/Qwen3.8-Flash-Next-GGUF/tree/main) — 111.4GB (UD-Q4_K_XL), 169GB (UD-Q6_K_XL), 188GB (Q8_0), 354GB (BF16) weight sizes, summed from each quant's per-file listing
- [ggml-org/llama.cpp docs/docker.md](https://raw.githubusercontent.com/ggml-org/llama.cpp/master/docs/docker.md) — `server-cuda`/`server-rocm` separate image tags
- [AMD chipsets product page](https://www.amd.com/en/products/processors/chipsets.html)
- [Tom's Hardware — Threadripper 3960X/3970X, sTRX4/TRX40 launch](https://www.tomshardware.com/news/amd-unveils-threadripper-3960x-and-3970x-ryzen-9-3950x-details-and-athlon-3000g/2)
- [PCWorld — Threadripper PRO launch, 128 PCIe lanes](https://www.pcworld.com/article/393181/amd-threadripper-pro-has-64-cores-128-pcie-lanes-and-8-channel-memory-support.html)
- [NVIDIA — GeForce RTX 3090 product page](https://www.nvidia.com/en-us/geforce/graphics-cards/30-series/rtx-3090/)
- [Lowyat.net — RTX 3060 official 170W TDP](https://www.lowyat.net/2021/232659/nvidia-geforce-rtx-3060-specifications-now-official-includes-3584-cuda-cores-and-170w-tdp/)
- [BuildMyServer — GTX 1080 180W/PCIe3.0/1×8-pin spec listing](https://buildmyserver.com/products/zotac-nvidia-geforce-gtx-1080-8gb-gddr5-180w-pcie-3-0-x16-double-wide-gpu)
- [MSI — GT 710 1GD5 LP spec page](https://www.msi.com/Graphics-Card/GT-710-1GD5-LP/Specification)
- [overclock3d — AMD Radeon AI PRO R9700 $1,299 MSRP](https://overclock3d.net/news/gpu-displays/amd-unveils-its-1299-radeon-ai-pro-r9700-32gb-workstation-gpu/)
- [pricehistory.app — R9700 street price tracker](https://pricehistory.app/p/powercolor-amd-radeon-ai-pro-r9700-32gb-BFcRhGIm)
- [bestvaluegpu.com — RTX 3090 used price tracker, Sep 2026](https://bestvaluegpu.com/history/new-and-used-rtx-3090-price-history-and-specs/)
- [gpupoet.com — RTX 3060 12GB used listings](https://gpupoet.com/gpu/shop/nvidia-geforce-rtx-3060)
- [Qwen Code docs — overview](https://qwenlm.github.io/qwen-code-docs/en/users/overview/)
- [Qwen Code docs — Auto Mode (fast-model pattern)](https://qwenlm.github.io/qwen-code-docs/en/users/features/auto-mode/)
- This repo: [`docker-compose.yml`](../../docker-compose.yml), [`.env.example`](../../.env.example), [`docs/server-planing.md`](../server-planing.md), [`qwen3.8-27b-quant.md`](qwen3.8-27b-quant.md), [`qwen3.8-27b-tool-calling.md`](qwen3.8-27b-tool-calling.md), [`rocm-gpu-pin-and-render-group.md`](rocm-gpu-pin-and-render-group.md), [`fast-model-choice.md`](fast-model-choice.md)
## Confidence/uncertainty summary
- **High confidence:** the KV-cache-per-token formulas for both dense models and Flash-Next (computed
directly from each model's own `config.json`, same method this repo's prior research already used
and cross-checked); the `n_ctx_per_seq = n_ctx / n_parallel` division behavior (directly evidenced by
a real server log in a llama.cpp GitHub issue, and independently already documented in this repo's
own `.env.example`) — and confirmed to apply identically at `--parallel 4` since the mechanism is
parallel-count-agnostic; official TDP figures for GTX 1080, RTX 2080, RTX 3060, RTX 3090, GT 710
(each cross-checked against 2+ independent spec listings or the vendor's own product page); the
TR4-is-PCIe3/sTRX4-is-PCIe4 generational split (direct launch-coverage quote); the existence of
separate `server-cuda`/`server-rocm` llama.cpp image tags; Qwen3.8-Flash-Next's `config.json`
architecture params and PR #27742's merge date/status and its own stated correctness caveats and
`-kvu` multi-slot requirement (all directly quoted from the primary source); the weight file sizes
for both models at all four quant tiers (summed directly from each HF repo's real file listing, not
estimated).
- **Medium confidence:** the compute-buffer/runtime-overhead estimate in §4/§11.7 (+3-6 GiB) —
extrapolated from one in-repo incident's before/after numbers, not a llama.cpp-documented formula,
and carried over to Flash-Next without re-derivation for its different architecture; the Gated
DeltaNet fixed recurrent-state size in §11.4 (~108 MiB/slot) — this doc's own derivation from the
published head-dimension config, not a value found in llama.cpp source or docs; whether
`--cache-type-k/v` quantization applies identically to Flash-Next's 12 full-attention layers as it
does to a plain transformer (reasonable extrapolation, not directly confirmed for this architecture);
whether `--n-cpu-moe`/`--override-tensor` actually work against Flash-Next's specific MoE tensor
layout (architecture-agnostic mechanism, but untested against this model by any primary source found);
real-world PCIe lane availability for 6 GPUs on a specific sTRX4 board (§5) — no single board's exact
lane map was fetched, this is a reasonable-but-unverified estimate from typical sTRX4 board behavior.
- **Low confidence / explicitly estimated, not cited fact:** all used-GPU marketplace pricing (§8) —
live asking-price snapshots from a single search pass, not sold-price data; the used sTRX4
CPU+motherboard combo price in the roadmap's stage 4 (§9) — not researched at all in this pass,
flagged as a placeholder estimate; whether YaRN-scaled 500k/1M context actually holds output
quality for either Qwen3.8-27B or Qwen3.8-Flash-Next — no primary source (Qwen's own docs included)
publishes long-context quality benchmarks past the 262,144 native length for either model, so this is
a known-unknown carried forward from each model card's "YaRN-extensible" claim, not a verified
capability; whether the specific `ghcr.io/ggml-org/llama.cpp:server-rocm` image currently cached on
this repo's server actually postdates PR #27742's 2026-08-27 merge — not checked against the live
server in this pass, flagged as an action item in §11.1 rather than a confirmed fact.
@@ -0,0 +1,249 @@
# Does the qwen-classifier need to match the main model's context window, and would upgrading it to Qwen3-8B or Qwen3-Coder-30B-A3B-Instruct fit on the current R9700?
**Date:** 2026-09-15
**Question raised:** should `qwen-classifier` be resized to `LLAMA_CTX_SIZE / LLAMA_PARALLEL` (131072, matching the
main model's per-slot context), should the classifier model itself move up to Qwen3-8B or
Qwen3-Coder-30B-A3B-Instruct, and does that need a second GPU?
**Answer: No, no, and not for this reason.** qwen-code's own docs state no context-size requirement for
`fastModel` at all — the "match the main model" premise doesn't come from any primary source. Separately, and
independently of context size: neither Qwen3-8B nor Qwen3-Coder-30B-A3B-Instruct fits in the ~6.1GiB of VRAM
actually free on the card today, at *any* context length, once weights alone are counted — this is a raw-VRAM
problem, not a context-window problem, exactly matching the "qwen8b needs to offload more to the RAM" intuition
in the request. A second GPU would solve the VRAM problem (and incidentally remove this repo's own
`GPU_MAX_HW_QUEUES=1` ROCm#5706 workaround from applying to this pair), but isn't deployed hardware today —
it's a rack-build/acquisition question, not a config change.
## 1. Does qwen-code require the fast/classifier model to match the main model's context window?
No — checked against the user's own three linked pages, fetched directly:
- **`fastModel` settings docs**: "Model used for generating prompt suggestions and speculative execution,"
configurable via `inherit` (main model), `fast`, a model ID, or `authType:model-id`; "Leave empty to use the
main model." The docs recommend "a smaller/faster model (e.g., `qwen3-coder-flash`) reduces latency and
cost" — **no context-window size or capacity requirement is stated anywhere on this page.**
Source: [qwen-code docs — Configuration / Settings, `#fastmodel`](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/settings/#fastmodel)
- **Approval Mode / Auto Mode classifier docs**: describes what the classifier evaluates (shell commands,
network calls, out-of-workspace edits) and its allow/block behavior, but **does not name a specific model or
state any context-window requirement** — the only operational note is that "when the classifier API is
unreachable, the action is blocked rather than allowed."
Source: [qwen-code docs — Approval Mode, `#4-auto-mode---classifier-driven-approval`](https://qwenlm.github.io/qwen-code-docs/en/users/features/approval-mode/#4-auto-mode---classifier-driven-approval)
- **Auto Mode "How it works"**: confirms the two-stage design (Stage 1: ~300ms, `{shouldBlock}` only; Stage 2:
chain-of-thought reconsideration, only on a Stage-1 block) and what data reaches the classifier — user text,
assistant tool-use calls, and tool-specific projections (truncated edit content, fetch URLs, shell command
text). **Tool results are explicitly never sent to the classifier.** It "uses your configured fast model
(`/model --fast`)," falling back to the main session model only if none is set. **No statement anywhere
requires or implies the fast model's context window match the main model's.**
Source: [qwen-code docs — Auto Mode, `#how-it-works`](https://qwenlm.github.io/qwen-code-docs/en/users/features/auto-mode/#how-it-works)
This confirms and sharpens what this repo's own `fast-model-choice.md` already found by reading qwen-code's
source directly (`packages/core/src/permissions/classifier-transcript.ts`: `MAX_TRANSCRIPT_MESSAGES=40`,
`MAX_HISTORICAL_ACTION_CHARS=4000`/message, worst case ~40-50K tokens, live-tested at 15,116 prompt tokens) —
that doc already called the original `131072` in `settings.json` "copied from the main model's entry, not a
real qwen-code requirement." The three docs pages fetched here add nothing that contradicts that: **there is no
primary-source basis for `LLAMA_CTX_SIZE / LLAMA_PARALLEL` symmetry between the two models.** The current
`65536` classifier ctx already carries ~1.5x margin over the real worst case.
## 2. VRAM math for Qwen3-8B and Qwen3-Coder-30B-A3B-Instruct as classifier candidates
Same method this repo already uses (`qwen3.8-27b-quant.md`, `fast-model-choice.md` §5): per-token KV cache =
`layers × 2(K+V) × kv_heads × head_dim × bytes`, read directly from each model's own `config.json`.
### Qwen3-8B
- Architecture (`Qwen/Qwen3-8B` `config.json`): `num_hidden_layers: 36`, `num_key_value_heads: 8`,
`num_attention_heads: 32`, `head_dim: 128`, `hidden_size: 4096`, `max_position_embeddings: 40960`,
`rope_scaling: null`.
Source: [Qwen/Qwen3-8B `config.json`](https://huggingface.co/Qwen/Qwen3-8B/raw/main/config.json)
- **Native context is 32,768 tokens**, not the 262,144 the user's brief assumed (that number belongs to
Qwen3-4B-Instruct-2507, a different, non-reasoning 2507-refresh model — Qwen3-8B is the earlier,
thinking-capable Qwen3 architecture with a materially smaller native window). Extending past 32K needs YaRN:
> "Qwen3 natively supports context lengths of up to 32,768 tokens. For conversations where the total length
> (including both input and output) significantly exceeds this limit, we recommend using RoPE scaling
> techniques to handle long texts effectively."
and llama.cpp-specific YaRN invocation is given explicitly:
`./llama-cli ... -c 131072 --rope-scaling yarn --rope-scale 4 --yarn-orig-ctx 32768`, with a documented
caveat that "all the notable open-source frameworks implement **static** YaRN, which means the scaling
factor remains constant regardless of input length, potentially impacting performance on shorter texts."
Source: [Qwen/Qwen3-8B-GGUF — Processing Long Texts](https://huggingface.co/Qwen/Qwen3-8B-GGUF#processing-long-texts)
- **Weights** (official Qwen quants, fetched from the GGUF repo file list): Q5_K_M = 5.85 GB, Q8_0 = 8.71 GB.
Source: [Qwen/Qwen3-8B-GGUF](https://huggingface.co/Qwen/Qwen3-8B-GGUF)
*(Not independently verified: unsloth's equivalent `UD-Q4_K_XL` quant, which is what this repo's
`docker-compose.yml`/`.env.example` actually download for every model deployed so far — the unsloth file
size wasn't fetched, only the official Qwen quants above. Treat Q5_K_M/Q8_0 as a reasonable bound, not the
exact file this repo would pull.)*
- Per-token KV cache: `36 × 2 × 8 × 128 × 2 bytes = 144 KiB/token` fp16 — identical to Qwen3-4B-Instruct-2507's
figure in `fast-model-choice.md` §5, since both share the same `layers/kv_heads/head_dim` triple.
| Context | KV (fp16) | KV (q8_0) | KV (q4_0, current classifier setting) |
|---|---|---|---|
| 65,536 (current classifier ctx) | 9.0 GiB | 4.5 GiB | **2.25 GiB** |
| 131,072 (user's proposed "match main model") | 18.0 GiB | 9.0 GiB | **4.5 GiB** |
Weights + KV (q4_0, smallest realistic combo):
| Context | Q5_K_M weights + q4_0 KV | Q8_0 weights + q4_0 KV |
|---|---|---|
| 65,536 | 5.85 + 2.25 = **8.1 GB** | 8.71 + 2.25 = **10.96 GB** |
| 131,072 | 5.85 + 4.5 = **10.35 GB** | 8.71 + 4.5 = **13.21 GB** |
### Qwen3-Coder-30B-A3B-Instruct
- Architecture (fetched from the shared Qwen3-30B-A3B-family `config.json`): `num_hidden_layers: 48`,
`num_key_value_heads: 4`, `num_attention_heads: 32`, `head_dim: 128`, `hidden_size: 2048`, **MoE**:
`num_experts: 128`, `num_experts_per_tok: 8` (8 of 128 experts active per token — confirms this is a sparse
MoE model, not a dense one like the 27B or 8B candidates; the "active params" figure describes *compute*
per token, not memory footprint — **all 128 experts' weights still have to be resident** wherever the model
is loaded, GPU or RAM).
Source: [Qwen/Qwen3-30B-A3B-family `config.json`](https://huggingface.co/Qwen/Qwen3-30B-A3B/raw/main/config.json)
- **UD-Q4_K_XL file size (the exact quant/quantizer this repo already standardizes on): 17.7 GB.** 30.5B total /
3.3B activated parameters. Native context "262,144 natively... can be extended further using Yarn to reach
1M tokens."
Source: [unsloth/Qwen3-Coder-30B-A3B-Instruct-GGUF](https://huggingface.co/unsloth/Qwen3-Coder-30B-A3B-Instruct-GGUF?show_file_info=Qwen3-Coder-30B-A3B-Instruct-UD-Q4_K_XL.gguf)
- Per-token KV cache: `48 × 2 × 4 × 128 × 2 bytes = 96 KiB/token` fp16 (smaller per-token than the 8B/4B
candidates, since `num_key_value_heads` is 4 here vs. 8 — but this saving is irrelevant given the weights
size below).
| Context | KV (fp16) | KV (q8_0) | KV (q4_0) |
|---|---|---|---|
| 65,536 | 6.0 GiB | 3.0 GiB | **1.5 GiB** |
| 131,072 | 12.0 GiB | 6.0 GiB | **3.0 GiB** |
Weights + KV (q4_0):
| Context | Total |
|---|---|
| 65,536 | 17.7 + 1.5 = **19.2 GB** |
| 131,072 | 17.7 + 3.0 = **20.7 GB** |
## 3. Does either candidate fit the ~6.1 GiB actually free on the card today?
**No — neither does, at either context size, even at the smallest quant/KV-quant combination tested.**
- Qwen3-8B's cheapest realistic combination (Q5_K_M weights + q4_0 KV at the *current* 65536 ctx, not even
the proposed 131072) is **8.1 GB — already ~2 GB over the measured 6.1 GiB free budget**, before accounting
for compute-buffer/batch overhead that `fast-model-choice.md` §"Implementation note" already found could add
meaningfully on top of the naive weights+KV estimate (that's exactly why the 4B classifier ended up needing
`--flash-attn on` and partial 28/36-layer offload instead of the originally-predicted comfortable full-GPU
fit).
- Qwen3-Coder-30B-A3B-Instruct isn't close at any setting tested — its weights alone (17.7 GB) are triple the
entire free budget, and this doesn't change with context size since the weights term dominates.
- This is a **VRAM-capacity problem, not a context-window problem** — directly confirming the "qwen8b needs to
offload more to the RAM" intuition in the original request. Reducing context doesn't fix it; the weights
don't fit regardless.
**CPU/RAM offload mechanics:** llama.cpp's `--n-gpu-layers` is documented as "max. number of layers to store in
VRAM, either an exact number, `'auto'`, or `'all'`" — the layers not selected are computed on CPU, with the
model loaded via mmap by default (same mechanism this repo's own `.env.example` already documents for
`LLAMA_GPU_LAYERS`: "if GPU+RAM ever can't hold the working set, the OS pages the rest in from disk
automatically"). For the MoE Coder-30B-A3B model specifically, this repo's own `.env.example` already flags the
more targeted alternative — `--n-cpu-moe`/`--cpu-moe`/`--override-tensor "exps"` — as the flags that "target
Mixture-of-Experts models (e.g. Qwen3.8-2.4T-A95B)," i.e. exactly this model's architecture: these offload only
expert-tensor weights to CPU while keeping attention/shared layers and KV cache on GPU, which is the
mechanically correct lever for an MoE model, unlike the blunt `--n-gpu-layers` used for the dense 8B/27B/4B
models. **Neither llama.cpp's own README nor the Qwen model cards fetched here document a quantified
performance cost for partial offload** — no primary source gives a "N layers offloaded = X% slower" figure.
Source: [llama.cpp `tools/server/README.md`](https://raw.githubusercontent.com/ggml-org/llama.cpp/master/tools/server/README.md)
What *is* directly measured, in this repo's own deployment history: CPU-only was tried first for the current,
much smaller 4B classifier and rejected — "too slow in practice: real classification calls blew past
OmniRoute's 60s timeout and retry-looped (504→499→504)" (`docker-compose.yml`'s `qwen-classifier` comment
block). An 8B dense model has roughly double the compute of the 4B model per token; a 30B-A3B model's *routing*
overhead on CPU (choosing 8 of 128 experts per token, each a separate weight lookup) adds a different kind of
cost that neither this repo nor the sources fetched here have measured. **Given the classifier's Stage 1 has an
explicit ~300ms latency budget** (`fast-model-choice.md` §1, from qwen-code's own docs), and this repo already
has one concrete data point that CPU offload breaks that budget at a smaller model size, extending either
candidate onto significant CPU offload carries real, unquantified latency risk — the same failure mode already
observed once, at a favorable (smaller) model size.
## 4. Does a second GPU solve this, and is one actually available?
**Not today.** `docs/server-planing.md` is a rack-build plan for "3-4x AMD Radeon AI PRO R9700 (32GB) GPUs" —
a future-state document, not present inventory. Every GPU-facing comment in this repo's own
`docker-compose.yml`/`.env.example`/`rocm-gpu-pin-and-render-group.md` consistently refers to "the single 32GB
R9700" and measures the "~6.1GiB free" budget against one physical card holding both `llama-server` and
`qwen-classifier`. Adding a second GPU is a hardware-acquisition and rack-build question — physically sourcing,
installing, and power/PCIe-provisioning a card per `server-planing.md`'s own build plan — not a
`docker-compose.yml`/`.env.example` change.
**If a second GPU were added**, it would directly remove one already-documented risk for this specific pair:
this repo's own `rocm-gpu-pin-and-render-group.md` traced the GPU-pinned-at-100%/ROCm#5706 bug to its precise
trigger condition —
> "The pin only appears with two concurrent HIP-context-holding processes **on the same GPU**... Root cause: an
> AMD MES (Micro Engine Scheduler) firmware bug triggered by HIP hardware-queue creation."
Source: [ROCm/ROCm#5706](https://github.com/ROCm/ROCm/issues/5706), via this repo's own
[`rocm-gpu-pin-and-render-group.md`](rocm-gpu-pin-and-render-group.md)
Since the confirmed trigger is *two HIP contexts sharing one physical card*, moving the classifier to its own,
second GPU would put each service on a single-HIP-context card — the condition that trips the bug wouldn't
exist for this pair anymore, and the `GPU_MAX_HW_QUEUES=1` workaround currently applied to both services
specifically because they share one card would no longer be load-bearing for *this* pair (it would still apply
if any future third service shared a card with either model). This wasn't independently re-verified across two
*separate* physical cards by any source fetched in this pass — it's a direct extrapolation from the confirmed
root cause, same category of caveat that doc's own author already flagged for its within-one-card claim.
## Bottom line / recommendation
1. **Don't apply `LLAMA_CTX_SIZE / LLAMA_PARALLEL` symmetry to the classifier.** No qwen-code primary source
states or implies the fast/classifier model needs to match the main model's context window. The real
requirement (§1, already established in `fast-model-choice.md`) is ~40-50K tokens worst case; the current
`65536` already has margin. Doubling to 131072 would only double VRAM spent on KV cache for a model that
won't otherwise fit anyway (§2-3).
2. **Don't upgrade the classifier to Qwen3-8B or Qwen3-Coder-30B-A3B-Instruct on the current single-GPU setup.**
Neither fits the ~6.1GiB actually free, at any context size — this is a weights-size problem, not a
context-window problem. Forcing it would mean either (a) shrinking the main 27B model's own VRAM footprint
to make room (a real trade-off against the primary model, not evaluated here), or (b) CPU/partial offload,
which this repo has direct, measured evidence already breaks the classifier's latency budget at a *smaller*
model size than either candidate.
3. **A second GPU is the clean fix for VRAM contention and would also retire the ROCm#5706 workaround's
relevance for this pair — but it isn't deployed hardware today.** `server-planing.md` is a future build
plan; this is an acquisition/rack-build decision, not something achievable via a config change right now.
4. If the actual underlying motivation is classifier *quality* (not context capacity), that's a separate,
legitimate question this doc doesn't answer — worth its own research pass rather than solving it via a
bigger model that doesn't fit the hardware.
## Sources
- [qwen-code docs — Configuration / Settings, `#fastmodel`](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/settings/#fastmodel)
- [qwen-code docs — Approval Mode, `#4-auto-mode---classifier-driven-approval`](https://qwenlm.github.io/qwen-code-docs/en/users/features/approval-mode/#4-auto-mode---classifier-driven-approval)
- [qwen-code docs — Auto Mode, `#how-it-works`](https://qwenlm.github.io/qwen-code-docs/en/users/features/auto-mode/#how-it-works)
- [Qwen/Qwen3-8B `config.json`](https://huggingface.co/Qwen/Qwen3-8B/raw/main/config.json)
- [Qwen/Qwen3-8B-GGUF](https://huggingface.co/Qwen/Qwen3-8B-GGUF)
- [Qwen/Qwen3-8B-GGUF — Processing Long Texts](https://huggingface.co/Qwen/Qwen3-8B-GGUF#processing-long-texts)
- [Qwen/Qwen3-30B-A3B-family `config.json`](https://huggingface.co/Qwen/Qwen3-30B-A3B/raw/main/config.json)
- [unsloth/Qwen3-Coder-30B-A3B-Instruct-GGUF](https://huggingface.co/unsloth/Qwen3-Coder-30B-A3B-Instruct-GGUF?show_file_info=Qwen3-Coder-30B-A3B-Instruct-UD-Q4_K_XL.gguf)
- [llama.cpp `tools/server/README.md`](https://raw.githubusercontent.com/ggml-org/llama.cpp/master/tools/server/README.md)
- [ROCm/ROCm#5706](https://github.com/ROCm/ROCm/issues/5706)
- [docs/research/fast-model-choice.md](fast-model-choice.md) (this repo — classifier transcript sizing,
qwen-classifier's real deployment history)
- [docs/research/qwen3.8-27b-quant.md](qwen3.8-27b-quant.md) (this repo — KV-cache-from-config.json method
reused here)
- [docs/research/rocm-gpu-pin-and-render-group.md](rocm-gpu-pin-and-render-group.md) (this repo — ROCm#5706
trigger condition and `GPU_MAX_HW_QUEUES` scoping)
- [docs/server-planing.md](../server-planing.md) (this repo — confirms only 1 of a planned 4 GPUs is deployed)
- `docker-compose.yml`, `.env.example` (this repo — current `qwen-classifier`/`llama-server` config and the
measured "~6.1GiB free" VRAM figure)
## Confidence / uncertainty summary
- **High confidence:** qwen-code's `fastModel`/Auto-Mode docs state no context-window requirement (direct
quotes from all three linked pages); Qwen3-8B's native 32,768 context and YaRN caveat (direct model-card
quote); Qwen3-Coder-30B-A3B-Instruct's MoE architecture and 17.7GB Q4_K_XL file size (direct from the
quantizer's own repo page); the KV-cache-per-token math for both candidates (computed directly from each
model's own `config.json`, same method already validated in this repo's prior research); the ROCm#5706
trigger condition being scoped to two HIP contexts on the *same* GPU (direct quote from this repo's own
prior research, itself sourced from the upstream issue).
- **Medium confidence:** the exact unsloth `UD-Q4_K_XL`-equivalent file size for Qwen3-8B — only the official
Qwen quants (Q5_K_M/Q8_0) were fetched, not unsloth's own repo, so the real number this repo would actually
download wasn't directly verified (bounded reasonably by the Q5_K_M figure, which is already the smallest
realistic option and still doesn't fit). The claim that CPU/partial-offload latency risk scales unfavorably
for larger/MoE models is a reasoned extrapolation from this repo's one measured data point (4B CPU-only
rejected) plus general MoE-routing-overhead reasoning, not a directly measured benchmark for either candidate.
- **Low confidence / not independently verified:** whether `GPU_MAX_HW_QUEUES=1`/ROCm#5706 genuinely has zero
relevance across two *separate* physical GPUs (extrapolated from the confirmed same-GPU trigger condition,
same caveat this repo's own prior research already flagged for its own claim); no primary source found that
quantifies llama.cpp's actual inference-speed penalty for partial `--n-gpu-layers` or `--n-cpu-moe` offload
in general — this is a documented gap in the sources checked, not a guessed number.
+33
View File
@@ -195,6 +195,39 @@ comfortably affords the higher-precision quant.
- [docs/research/qwen3.8-27b-tool-calling.md](qwen3.8-27b-tool-calling.md) (this repo — cross-referenced
for the 27B model's own, still-open, tool-calling parser bugs)
## Implementation note (2026-09-09) — what actually shipped, and why it differs
The model pick (`Qwen3-4B-Instruct-2507`) held up and is what's deployed. Several sizing assumptions in
this doc didn't survive contact with the real deployment, though — worth recording so the next person
tuning this doesn't re-derive the same corrections from scratch:
- **Service name is `qwen-classifier`, not `llama-server-fast`** — this doc's proposed name never got
used. There's no `LLAMA_FAST_CTX_SIZE`/`LLAMA_FAST_PARALLEL` in `.env.example` either; the real config
lives inline in `docker-compose.yml`'s `qwen-classifier` command.
- **CPU-only was tried first and rejected** — this doc's VRAM budget analysis (§5) assumed GPU
residency from the start, but the actual rollout path tried CPU-only first (to sidestep VRAM
contention entirely) and found it too slow: real classification calls blew past OmniRoute's request
timeout and retry-looped. Moved to GPU after that, which is what §5's math was for all along.
- **Q4_K_XL weights, not Q8_0** — §5's "~2.4GB headroom" case assumed Q8_0 (4.28GB). In practice, fitting
the classifier onto the R9700 *alongside* the 27B model (not in an assumed-empty 7GB budget) left only
~6.1GB free VRAM total, and even Q4_K_XL (2.37GB) plus full-context KV cache didn't leave enough real
margin at full GPU offload — see the "measured live" numbers in `docker-compose.yml`'s `qwen-classifier`
comment block. Landed on **partial GPU offload (28/36 layers)** instead of full offload, which is not a
case this doc considered at all.
- **65536 context, not 8192** — §5 sized the context "in the low thousands," reasoning from qwen-code's
two-stage classifier description alone. Directly reading qwen-code's actual source
(`packages/core/src/permissions/classifier-transcript.ts`: `MAX_TRANSCRIPT_MESSAGES=40`,
`MAX_HISTORICAL_ACTION_CHARS=4000`/message) puts the real worst case at ~40-50K tokens — confirmed
live, a real classifier call during testing hit 15,116 prompt tokens. 8192 would have been undersized
for real usage; 65536 gives margin without the original setting.json value (131072, copied from the
main model's entry, not a real qwen-code requirement) wasting VRAM for no reason.
- **§4's `--reasoning off` recommendation was initially missed** in the first deployment pass and added
only once this doc was re-read while writing this note. It's now in `docker-compose.yml`'s
`qwen-classifier` command, per this doc's own "add it regardless, no-cost safety net" reasoning — still
unconfirmed whether the current `ghcr.io/ggml-org/llama.cpp:server-rocm` build actually reproduces
#20809 (nothing in testing so far surfaced `reasoning_content` where `tool_calls` was expected, but
that wasn't specifically probed for either).
## Confidence/uncertainty summary
- **High confidence:** Qwen3-4B-Instruct-2507's non-thinking-only status (direct model-card quote);
@@ -0,0 +1,84 @@
# OmniRoute's per-connection semaphore timeout — hardcoded, not a setting
**Date:** 2026-09-09
Any OmniRoute connection whose upstream can only handle a small, fixed number of concurrent requests
(this repo's `llama-server`/`qwen-classifier`, both effectively single-GPU-slot-limited) can hit a hard
30-second reject once more requests are in flight than the connection's `maxConcurrent` allows — even
though the request would have succeeded fine if it had just waited its turn. This surfaced first as the
`pr-agent`/`CodersPlacePI` 429/504 investigation (see the issue tracker), then again while sizing
`qwen-classifier`. Recorded here so it doesn't have to be re-diagnosed from scratch next time.
## The error
```
{"error":{"message":"Semaphore timeout after 30000ms for <provider>:<connectionId>","type":"rate_limit_error","code":"rate_limit_exceeded"}}
```
## Root cause (confirmed against OmniRoute's own source, [diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute))
`open-sse/services/accountSemaphore.ts`:
```ts
const DEFAULT_TIMEOUT_MS = 30_000;
...
function createSemaphoreTimeoutError(semaphoreKey, timeoutMs) {
const error = new Error(`Semaphore timeout after ${timeoutMs}ms for ${semaphoreKey}`);
error.code = "SEMAPHORE_TIMEOUT"; // classified upstream as HTTP 429 rate_limit_exceeded
return error;
}
```
Called from `open-sse/handlers/chatCore.ts`:
```ts
await acquireAccountSemaphore(accountSemaphoreKey, {
maxConcurrency: accountSemaphoreMaxConcurrency, // = the connection's maxConcurrent
signal: streamController.signal,
// no timeoutMs passed → always falls back to the hardcoded 30_000 default
})
```
This is **not** the same thing as OmniRoute's documented quota-share concurrency gate
(`open-sse/services/combo/quotaShareConcurrency.ts`, key prefix `qsconn:`), which is deliberately
fail-open per its own doc comment ("a saturated queue or timeout proceeds without a slot rather than
ever rejecting a dispatchable request") — that one only matters for quota-share combos. The account
semaphore above is a *different*, always-on gate keyed `provider:connectionId`, has no fail-open path,
and its 30-second timeout is a bare `await` with nothing passed to override it — not exposed via
`/api/resilience`, not an env var, not a dashboard toggle, not documented anywhere in
`docs/reference/ENVIRONMENT.md`. It's a hardcoded constant in vendored code.
Also **not** the same as `requestQueue.maxWaitMs` (visible via `GET /api/resilience`, this deployment
already has it at `86400000`) — that one bounds a Bottleneck-managed *execution* timer that starts only
after dispatch, surfaces as HTTP 504 `RATE_LIMIT_EXECUTION_TIMEOUT`, and is unrelated to the 429 above.
## What actually fixes it
The 30s ceiling itself cannot be raised — no config surface reaches it in the current OmniRoute build.
Two real options:
1. **Bypass the semaphore, let the upstream's own queue absorb concurrency instead.**
`maxConcurrency == null || maxConcurrency <= 0` fully bypasses `accountSemaphore.ts` (see
`isBypassed()`) — no gate, no 30s timer, requests pass straight through to the upstream. This only
works if the upstream itself queues gracefully with no reject-timeout of its own — confirmed true for
llama.cpp's server (`tools/server/server-queue.cpp` has no queue-wait timeout; excess requests just
wait for a free slot). If you do this, also raise the connection's own
`providerSpecificData.timeoutMs` (bounded 1ms24h, `MAX_PROVIDER_SPECIFIC_TIMEOUT_MS`) generously —
that's the timer that now matters: "did the upstream return response headers in time," which on
llama.cpp means the full queue-wait-then-generate time, since llama.cpp sends **zero bytes, not even
headers**, while a request sits queued (confirmed in `server-context.cpp`: `res->status = 200` is only
set after the first generated token exists).
2. **Reduce how often more than `maxConcurrent` requests actually stack up** — e.g. the
`pr-agent`/Gitea webhook fix (narrowing the subscribed event list so one PR action doesn't fire 3+
near-simultaneous AI calls). Doesn't remove the ceiling, just makes it less likely to be hit.
Applied in this repo: `llama-server`'s OmniRoute connection has `maxConcurrent: null` and
`providerSpecificData.timeoutMs: 1200000` (20 min — matches worst-case 2-slots-busy + queued + own
generation time). `qwen-classifier` uses a much shorter `timeoutMs: 120000` since it isn't
GPU-contended the same way — see `docs/coding-cli-setup/qwen-code.md`.
## Sources
- [diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute) — `open-sse/services/accountSemaphore.ts`, `open-sse/handlers/chatCore.ts`, `open-sse/services/combo/quotaShareConcurrency.ts`, `open-sse/services/rateLimitManager.ts`, `docs/architecture/RESILIENCE_GUIDE.md`, `docs/reference/ENVIRONMENT.md`
- [ggml-org/llama.cpp](https://github.com/ggml-org/llama.cpp) — `tools/server/server-queue.cpp`, `tools/server/server-context.cpp`
- `src/shared/validation/providerSpecificData.ts` (OmniRoute) — `MAX_PROVIDER_SPECIFIC_TIMEOUT_MS` bound
@@ -0,0 +1,397 @@
# A 48-minute total outage on `qwen3.8-27b-local`, and the third OmniRoute timeout mechanism this repo hadn't documented yet
**Date:** 2026-09-15
**Verdict:** The error — `"[504]: Direct response did not start within 30000ms — retrying on a fresh socket"`
comes from a **third, previously-undocumented OmniRoute timeout mechanism** (`OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS`,
default 30s), distinct from both timeouts already recorded in
[`omniroute-account-semaphore-timeout.md`](./omniroute-account-semaphore-timeout.md) and
[`omniroute-non-ping-sse-stream-timeout.md`](./omniroute-non-ping-sse-stream-timeout.md). It exists specifically to
recover from a *stale pooled TCP socket* by retrying once on a brand-new connection — but in the incident analyzed
here, **both** the original attempt and the fresh-socket retry timed out, repeatedly, for 46 requests over 48
straight minutes with zero successes. That pattern rules out a stale-socket explanation (a fresh socket bypasses
the pool entirely) and points instead at the upstream itself — `llama-server`, or the R9700 GPU underneath it —
being genuinely unresponsive for the whole window. The best primary-source match for that symptom is an **open,
still-unresolved AMD ROCm bug specific to this exact GPU** ([ROCm/legacy-rocm-build#6630](https://github.com/ROCm/legacy-rocm-build/issues/6630)):
an MES-firmware hang during generation on `gfx1201`/R9700 that leaves the process alive but stuck, sometimes for
no logged reason at all. No config change fixes this — raising the 30s timeout only makes each failed attempt
take longer to give up, it doesn't un-wedge a hung GPU.
## The evidence
**Source:** `omniroute-request-logs-6h-2026-09-15.json`, a 339-entry OmniRoute request-log export the user pulled
from the dashboard, covering `2026-09-15T12:49:52Z``18:44:54Z`. Every entry with a non-200 status (66 of them)
is a `POST /v1/chat/completions` against `qwen3.8-27b-local` (`/models/Qwen3.8-27B-UD-Q4_K_XL.gguf`), all on the
same `connectionId` (`649a2d3e-7527-488e-9b8a-dc4ac2624176`) and the same `provider`
(`openai-compatible-chat-a7bda643-6687-41f4-b75d-fd2cab746874`) — a single upstream connection, not a fan-out
artifact.
Sorting every error by timestamp shows **one continuous outage**, not scattered slow requests:
- Last successful `/v1/chat/completions` before the outage: `15:18:12.285Z`
- **First failure:** `15:25:06.415Z` — status 504, `"[504]: Direct response did not start within 30000ms —
retrying on a fresh socket"`, duration `60186ms`
- **Every single `/v1/chat/completions` attempt** from `15:25:06.415Z` through `16:13:29.502Z` failed — 46× 504
(all clustered `60021`-`60324ms`, i.e. two back-to-back 30s attempts, both failing) interleaved with 20× 499
(`"Request aborted"` / `"Client disconnected: request_signal_aborted"`, durations `1.4s`-`99.97s` — these are
qwen-code giving up client-side while OmniRoute was still mid-retry)
- **First successful recovery:** `16:13:50.388Z`, `20873ms` — 21 minutes after the last failure attempt cluster,
i.e. the very next attempt after the outage window succeeded normally
- No successful `/v1/chat/completions` call appears anywhere inside the `15:25:06Z`-`16:13:29Z` window — confirmed
by filtering all 154 `/v1/chat/completions` log entries in that range: every one is 504 or 499.
`git log --since=2026-09-14 --until=2026-09-16` shows **zero commits** in this repo on 2026-09-15 — the outage
correlates with no deploy, `scripts/update.sh` run, or config change on this end.
**A second, independent data point** (see caveat below): the user also pasted a large raw text table, copied
directly from OmniRoute's dashboard UI rather than the JSON export, showing the **`qwen-classifier`** connection
(`qwen3-4b`, both the `-UD-Q4_K_XL.gguf` file this repo's `docker-compose.yml` currently defaults to, and a
`-UD-Q8_K_XL.gguf` variant that appears **nowhere** in this repo's checked-in `docker-compose.yml`/`.env.example`
— either tested by hand against `LLAMA_CLASSIFIER_MODEL_FILE` outside version control, or evidence of drift worth
checking directly on the server) failing repeatedly across two accounts (`Haylan`, `qwen-cli-main`), with the
same signature: `TI: 0|TO: 0` (zero tokens either direction — failed before generating anything) and durations
clustering at exactly `60.0`-`60.4s` for the 504s. That's the identical two-attempts-at-30s-each shape as the 27B
outage above, strongly suggesting the same underlying mechanism, though — important caveat — **this table is not
present in the 6-hour JSON export and covers a different, longer time range** (timestamps back to `01:21` and
`23:54` on unspecified dates), so it cannot be directly time-correlated against the 27B outage above. Treat it as
corroborating evidence that this failure mode recurs on both local model connections, not as proof they failed at
the same moment.
## Root cause: `OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS`, a mechanism built for a different problem
Confirmed directly against OmniRoute's own source, [diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute)
(same repo the two existing timeout docs already cite) — `open-sse/utils/directResponseStartTimeout.ts`:
```ts
const DEFAULT_DIRECT_HEADERS_TIMEOUT_MS = 30_000;
const DIRECT_RESPONSE_START_TIMEOUT_CODE = "DIRECT_RESPONSE_START_TIMEOUT";
export function resolveDirectHeadersTimeoutMs(
env: Record<string, string | undefined> = process.env
): number {
const raw = env.OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS;
if (raw == null || raw.trim() === "") return DEFAULT_DIRECT_HEADERS_TIMEOUT_MS;
...
}
function createDirectResponseStartTimeout(timeoutMs: number): Error & { code: string } {
const err = new Error(
`Direct response did not start within ${timeoutMs}ms — retrying on a fresh socket`
) as Error & { code: string };
...
}
```
"Direct" here means **direct (no-proxy) egress** — confirmed in `open-sse/utils/proxyFetch.ts`, which routes any
connection with no configured upstream HTTP proxy through this path (as opposed to OmniRoute's separate
proxy/relay egress paths). Every local connection in this repo (`llama-server`, `qwen-classifier`, both reached
over the `ai-stack` Docker network with no proxy) is "direct" — so this timeout mechanism governs **every**
request to either local model, streaming or non-streaming alike, not just non-streaming JSON responses as the
name might suggest.
### Why it exists (and why it didn't help here)
Two OmniRoute issues, both with dedicated regression tests in the repo, explain the actual design intent:
- **#4252** (`tests/unit/proxyfetch-retry-fresh-socket-4252.test.ts`): "Undici dispatcher fails on direct provider
requests in 502 bursts" — the default direct dispatcher pools keep-alive sockets; some upstreams silently close
idle pooled sockets, so the next request reusing one fails with `UND_ERR_SOCKET`. Fix: retry once on a **fresh,
no-keep-alive dispatcher** (`getRetryDispatcher()`, a different instance from `getDefaultDispatcher()`) so the
retry can't grab another already-dead pooled socket.
- **#10214** (`tests/unit/proxyfetch-direct-response-start-timeout-10214.test.ts`): "Direct (no-proxy) requests
stall on a silently-dropped pooled keep-alive socket until the caller's deadline or a service restart" — the
harder case: a pooled socket that dies **without even an error**, just silence. Undici's `headersTimeout`
default (600s) is far too slow to catch this in practice, and the existing #4252 retry never fires because no
error is thrown to trigger it. The fix bounds each direct attempt's response-start wait to
`OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS` (30s default) via `directFetchWithBoundedResponseStart`, and retries
**once** on the same fresh no-keep-alive dispatcher from #4252 when that bound is hit.
Both fixes assume the *socket* is the problem, not the upstream. `directFetchWithBoundedResponseStart`'s own
implementation (`open-sse/utils/directResponseStartTimeout.ts`) is exactly two attempts: pooled, then fresh. When
attempt 2 — a brand-new socket that cannot possibly be a zombie pooled connection — **also** times out at 30s,
the retry logic has nothing left to try and the request fails with `DIRECT_RESPONSE_START_TIMEOUT_CODE`
(surfaced as the 504 seen in the logs). A fresh socket succeeding to *connect* but the *server* never sending a
response is exactly what "the upstream process is alive but stuck" looks like from OmniRoute's side — it can't
distinguish "GPU is wedged mid-generation" from "stale pooled socket," because both present as "nothing came
back in 30s." 46 consecutive both-attempts-failed cycles over 48 minutes is far outside what a transient stale-socket
burst (the scenario #4252/#10214 were built for) would produce; it's consistent with a sustained upstream
outage instead.
**Not currently configured in this repo**: `grep`-ing `docker-compose.yml` and `.env.example` for
`OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS` finds nothing — this deployment runs on the unmodified 30s default. (This
is also, notably, a *fourth* data point alongside the two already-documented mechanisms and the `requestQueue.maxWaitMs`/
`RATE_LIMIT_EXECUTION_TIMEOUT` timer mentioned in passing in `omniroute-account-semaphore-timeout.md` — OmniRoute
has at least four independent timeout knobs guarding different stages of a request's life, three of them
30-second-flavored by default, which is worth keeping in mind the next time an unfamiliar timeout string shows up.)
## Why the upstream itself was likely unresponsive: ROCm/legacy-rocm-build#6630
This session has **no SSH/shell access to the actual R9700 server** — there's no SSH config, and nothing in
`scripts/` does remote exec, confirmed by inspecting `scripts/update.sh` and the absence of any `~/.ssh/config`
entry for the box. So none of the following is confirmed against this specific incident's `dmesg`/`rocm-smi`/
`docker logs` output — it's the closest primary-source match to the *symptom*, not a diagnosis of *this* outage.
[ROCm/legacy-rocm-build#6630](https://github.com/ROCm/legacy-rocm-build/issues/6630) ("gfx1201 R9700 ROCm 7.14
llama.cpp generation hang, MES queue failure and PSP reset -62; Vulkan passes") is an **open**, actively
investigated issue (created 2026-08-19, most recent update 2026-08-28, no fix landed) that reproduces on **the
exact same GPU this repo runs on** — Radeon AI PRO R9700, `gfx1201` — running **llama.cpp with `-fa on`** (this
repo's `llama-server` also runs `--flash-attn on`), with a controlled Vulkan-vs-ROCm A/B: Vulkan completes
normally, ROCm hangs during token generation. Direct quotes:
> "During the ROCm generation stall: GPU busy reached 100%, memory busy remained 0%, VRAM use was only about 1.1
> GB, **the container remained alive but made no output progress**."
> "when MES stops responding, **the driver can stay unaware of it indefinitely** — the failure only surfaces when
> something happens to send the next MES message... if a run is left alone after it stops making progress, the
> kernel prints nothing at all, so a hang can look like a slow workload rather than a fault."
> "the failure is probabilistic, not deterministic... a single passing run on this host does not indicate a
> healthy configuration."
The thread (12 comments as of this research pass, an AMD engineer `harkgill-amd` participating) has ruled out,
one at a time, `uni_mes=0`, `mes_log_enable=1`, ROCm 6.4.4, ROCm 7.14, ROCm 10.0.0 stable, the latest TheRock
nightly, and GFXOFF-disable — **no confirmed fix or workaround exists in the thread as of this research pass**.
A related comment on the same issue (`chrisfranson`) reports the identical MES `REMOVE_QUEUE`/MODE1-reset
signature from a **completely unrelated workload** (headless LibreOffice with OpenCL) on the same `gfx1201`
silicon, reinforcing that this is a driver/firmware-level fault under general GPU load, not something specific
to llama.cpp's request pattern.
**This is a different bug from the one already mitigated in this repo.** `docs/research/rocm-gpu-pin-and-render-group.md`
already documents and works around `ROCm/ROCm#5706` (clock/power pinned at boost whenever two concurrent HIP
contexts share the GPU — fixed via `GPU_MAX_HW_QUEUES=1`, already set on both `llama-server` and `qwen-classifier`
in `docker-compose.yml`). #5706's symptom is elevated power draw with the GPU still working; #6630's symptom is
generation fully halting with `gpu_busy=100%`/`mem_busy=0%` and MES no longer responding at all — a real hang, not
a clock-pin inefficiency. `GPU_MAX_HW_QUEUES=1` targets #5706's specific trigger (hardware-queue oversubscription
across concurrent HIP processes) and has no evidence in #6630's thread of affecting that bug — #6630 reproduces
in single-GPU, single-process benchmarks with no second HIP context involved at all, so the already-applied fix
should not be assumed to help here.
## What would actually resolve this vs. what wouldn't
- **Raising `OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS`** — not recommended as a fix. It would make each failed attempt
take longer before giving up (worse latency during a real hang), without addressing why the GPU stopped
responding. It's the right lever only if future evidence shows genuinely-slow-but-working responses being
mistaken for hangs (the same shape as the already-fixed `REQUEST_TIMEOUT_MS` issue in
`omniroute-non-ping-sse-stream-timeout.md`) — this incident's 46-for-46 both-attempts-failed pattern over 48
minutes doesn't fit that shape.
- **Concrete next step for whoever has server access when this recurs**: check `dmesg | grep -i amdgpu` and
`journalctl -k` on the R9700 host for `MES(...) failed to respond`, `GPU reset begin`, or `PSP resume failed`
lines matching #6630's signature, and `docker logs llama-server`/`docker logs qwen-classifier` to see whether
the process was alive-but-stuck (consistent with #6630) versus crashed/restarted (which would point elsewhere).
Capturing this during a live incident is the only way to move this from "best primary-source match" to
"confirmed root cause."
- **Monitor [ROCm/legacy-rocm-build#6630](https://github.com/ROCm/legacy-rocm-build/issues/6630)** for a fix —
it's open and active (AMD engineer engaged as of 2026-08-26); no released ROCm version as of this research pass
is confirmed clean.
- **The `-UD-Q8_K_XL.gguf` classifier variant in the pasted table but absent from version control** is worth a
direct look on the server (`cat .env` / `docker inspect qwen-classifier` for the actual `LLAMA_CLASSIFIER_MODEL_FILE`
in effect) — outside this research pass's reach without server access, flagged here so it isn't lost.
## Recovery: how the hang actually clears (or doesn't) — addendum, 2026-09-15
Follow-up question: what actually recovers the socket once this hits, given it's been observed to stay wedged
for days at a time? Pulled the full comment thread on
[ROCm/legacy-rocm-build#6630](https://github.com/ROCm/legacy-rocm-build/issues/6630) directly via the GitHub API
(12 comments, `angelhalo` as primary reporter, `harkgill-amd` as the responding AMD engineer, plus one
corroborating report from `chrisfranson` on unrelated hardware/workload) — the earlier research pass's source list
cited this issue but hadn't read the full thread. Three things fall directly out of it:
**There is no reliable in-band recovery.** The driver doesn't notice the hang on its own — direct quote:
"when MES stops responding, the driver can stay unaware of it indefinitely — the failure only surfaces when
something happens to send the next MES message." In a captured live hang, "every driver-managed ring is
completely idle while the GPU reports 100% busy," `dmesg` has zero amdgpu lines, and no task is in D-state —
so from the OS's perspective nothing is wrong; only sending the GPU another command (which killing/restarting
the stuck process does) triggers the driver to discover the wedge and attempt its own MODE1 reset.
**Once triggered, that reset itself is a coin flip across three documented outcomes**, not a guaranteed fix:
1. **Clean recovery** — `GPU reset succeeded, trying to resume`, PSP resumes, the card comes back (VRAM is
wiped — "VRAM is lost due to GPU reset!" — so the container needs a real restart to reload the model, a plain
process respawn isn't enough even when the reset itself works).
2. **Failed resume** — `PSP resume failed`, `GPU reset end with ret = -62` (the original report's own outcome) —
the reset attempt itself fails, leaving the GPU in a worse state than before.
3. **Full kernel soft-lockup** — `chrisfranson`'s independent report (different workload — headless LibreOffice
OpenCL, different card — RX 9070 XT, same `gfx1201` silicon) hit outcome 2 or 3 twice out of three times:
"the whole system hard-locked (kernel soft lockup pegging a CPU at ~90-100% softirq, requiring a physical
power cycle)."
`angelhalo` deliberately left one hang untouched rather than killing the process, to observe it without
contaminating the state with a reset: "I recovered only with a subsequent cold power cycle" — no reset was ever
triggered because nothing sent the GPU another message. Their standard test procedure between every single run
in this thread is "a cold power cycle (AC removed, ≥30 s)," specifically **not** a warm/soft reboot — stated
reason: "on this card a MODE1 reset takes the host down with it," meaning even the OS's own reboot path can't
be trusted to come back cleanly once this GPU is in a bad state. This is the practical answer to "why does it
stay stuck for days": nothing about the hang self-clears, `docker`'s `restart: unless-stopped` policy never
fires because the container process is alive and never exits (confirmed: this repo's `llama-server` and
`qwen-classifier` services have no `healthcheck` block at all — only `omniroute` itself does, a plain TCP
connect check on its own dashboard port, which says nothing about whether `llama-server`/`qwen-classifier` are
responding) — so a hang persists until a human notices the symptom (requests failing) and manually intervenes,
and "days" is just however long that takes to notice on a homelab box, not a property of the hang itself.
**No fix or reliable mitigation exists as of this reading (2026-08-28, the thread's latest comment).**
`harkgill-amd` (AMD) could not reproduce locally and asked for a nightly-driver retest; `angelhalo` retested and
it still failed. Every other variable tested still hangs: ROCm 6.4.4 through 10.0.0 stable, TheRock nightlies,
`amdgpu.uni_mes=0`, `cwsr_enable=0`, `mes_log_enable=1`, GFXOFF disabled, two different physical R9700 cards, both
llama.cpp and vLLM. The thread's own conclusion, as of the last comment: "a probabilistic lost-completion event"
with no known trigger to avoid and no known driver/firmware combination that's clean.
**Practical takeaway for this repo, given no upstream fix exists:**
- A restart *might* recover it, *might* make it worse (failed PSP resume), and *might* take the whole host down
requiring a physical power cycle — there's no way to know in advance which outcome a given hang will produce.
- Nothing currently watches for this automatically. Docker's `restart: unless-stopped` is the wrong tool (process
doesn't exit) — recovering automatically would need a `healthcheck` against `llama-server`'s own `/health`
endpoint (llama.cpp's built-in liveness endpoint) paired with something that acts on an `unhealthy` status,
since Docker itself doesn't restart on failed healthchecks without an external watcher (e.g. `willfarrell/autoheal`
or equivalent) — not evaluated here, flagged as a real gap, not a recommendation to implement blind: an
automated restart during a hang that's about to fail its PSP resume and lock the host could turn a
"requests are failing" incident into "the box needs a physical power cycle" automatically and unattended,
which is a real downside worth weighing against faster detection.
- Given the reset outcome is unpredictable, the safest manual recovery when this is caught live is: restart the
affected container, then immediately check `dmesg | grep -i amdgpu` for `PSP resume failed` or a soft-lockup
signature before assuming it's fixed — if either appears, a full reboot (and per this thread's own testing
practice, possibly a genuine AC power cycle rather than a warm reboot) is the next step, not a second restart
attempt.
## Caveats and open questions
- **JSON export vs. pasted table are two different, non-overlapping captures.** The JSON file is a precise 6-hour
window with full per-request detail; the pasted table is a longer, dashboard-UI-copied range with less
structure and no verifiable overlap with the JSON file's timestamps. A fresh multi-day JSON export (same
`request-logs` endpoint used to produce the file analyzed here) would let a future pass check whether the
classifier's failures and the 27B model's outage are literally simultaneous (strong evidence for a shared
GPU-level cause) or independent recurrences of the same mechanism on separate schedules.
- **Why the outage self-recovered after ~48 minutes with no observed restart is unexplained.** #6630's thread
describes hangs resolving via an explicit GPU reset (sometimes failing, requiring reboot) — not a case of a
hang clearing on its own after a fixed interval. Nothing in the available data (no server access) confirms
whether a restart happened that isn't visible from OmniRoute's logs, or whether this specific hang genuinely
self-cleared, which would be a data point *against* the #6630 hypothesis worth capturing next time.
- **Live reproduction was not attempted.** The user suggested testing tool-calls against the classifier via the
Windows-side qwen-code CLI (`C:\Users\aerli\AppData\Local\qwen-code\bin\qwen.cmd`) to try to reproduce a
"Direct response did not start" failure live. Skipped for this pass: qwen-code requires an interactive/
already-authenticated session to drive meaningfully, and deliberately trying to reproduce a GPU hang against
the shared production classifier risked a genuine 60s+ stall on infrastructure other work depends on, for
uncertain diagnostic payoff given the strength of the log-based and source-based evidence already gathered.
Worth doing deliberately, with server access on hand to capture `rocm-smi`/`dmesg` simultaneously, rather than
as a quick check from this pass.
## Sources
- `omniroute-request-logs-6h-2026-09-15.json` — OmniRoute dashboard request-log export provided by the user
(2026-09-15, 339 entries, `12:49:52Z`-`18:44:54Z`)
- User-pasted OmniRoute dashboard table (`qwen-classifier`/`qwen3-4b` failures, separate capture window)
- [diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute) —
`open-sse/utils/directResponseStartTimeout.ts`, `open-sse/utils/proxyFetch.ts`, `open-sse/utils/proxyDispatcher.ts`,
`tests/unit/proxyfetch-direct-response-start-timeout-10214.test.ts`, `tests/unit/proxyfetch-retry-fresh-socket-4252.test.ts`,
`open-sse/handlers/chatCore/upstreamTimeouts.ts`
- [ROCm/legacy-rocm-build#6630](https://github.com/ROCm/legacy-rocm-build/issues/6630) — open R9700/gfx1201
llama.cpp generation-hang issue, full comment thread (2026-08-19 through 2026-08-28)
- [`docs/research/omniroute-account-semaphore-timeout.md`](./omniroute-account-semaphore-timeout.md) — the
first already-documented 30s OmniRoute timeout (account semaphore, 429, hardcoded)
- [`docs/research/omniroute-non-ping-sse-stream-timeout.md`](./omniroute-non-ping-sse-stream-timeout.md) — the
second already-documented timeout (first-SSE-event deadline, `REQUEST_TIMEOUT_MS`-derived)
- [`docs/research/rocm-gpu-pin-and-render-group.md`](./rocm-gpu-pin-and-render-group.md) — the already-mitigated,
*different* R9700/gfx1201 MES bug ([ROCm/ROCm#5706](https://github.com/ROCm/ROCm/issues/5706), clock-pin/power,
not a hang)
- Local `docker-compose.yml`, `.env.example` (grepped directly, confirming `OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS`
is unset / on the 30s default, and that `GPU_MAX_HW_QUEUES=1` is already applied to both GPU services)
- `git log --since=2026-09-14 --until=2026-09-16` (this repo, confirming zero commits during the outage window)
## Confidence / uncertainty summary
- **High confidence**: the exact mechanism and semantics of `OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS` /
`directFetchWithBoundedResponseStart` (read directly from OmniRoute's own source and its two regression test
files, which spell out the intent in comments referencing the originating issues); the JSON log's chronology,
single-connection scope, and the "two ~30s attempts, both failing" shape of every 504 (computed directly from
the log file); that this timeout is unconfigured in this repo (direct grep); that no commits landed in this
repo during the outage window (direct `git log`).
- **Medium confidence**: that ROCm/legacy-rocm-build#6630 is the actual root cause of *this specific* outage.
The GPU model, driver-family symptom shape (`gpu_busy=100%`/`mem_busy=0%`, alive-but-stuck, sometimes
logged/sometimes silent), and `-fa on` usage all match closely, and it's an open/unresolved/actively-discussed
issue as of this research pass — but nothing from this incident's own `dmesg`/`rocm-smi` output was available
to confirm it directly (no SSH access), so this is the best primary-source match to the symptom, not a
confirmed diagnosis.
- **Low confidence / open**: why the outage recovered on its own after ~48 minutes with no observed restart;
whether the classifier's pasted-table failures share the exact same triggering event as the 27B outage
analyzed here (same failure signature, but no verified time-overlap between the two data sources); the
provenance of the `-UD-Q8_K_XL.gguf` classifier variant seen in the pasted table but absent from version
control.
## Live test, 2026-09-15: the classifier is measurably too slow at its own documented worst case — independent of any hang
Before scoping a fix, tested the live `qwen-classifier` backend directly against realistic worst-case load,
per the user's request to gather fresh evidence rather than design blind. Two attempts to reproduce this through
qwen-code itself first surfaced an unrelated, separately-useful finding; the direct backend test below is what
actually answered the question.
### qwen-code's own headless mode never reaches the classifier
Ran `qwen --approval-mode auto <prompt>` (positional/one-shot, non-interactive) from the Windows-side install
(`C:\Users\aerli\AppData\Local\qwen-code\bin\qwen.cmd`, which has both `fastModel` and the `omniroute-search` MCP
server already configured), asking it to run a shell `dir` and use the web-search MCP tool. Both attempts hit a
wall before any classifier request was even sent:
- The MCP tool call was refused outright: `Warning: Tool "mcp__omniroute-search__search" requires user approval
but cannot execute in non-interactive mode. ... use the -y flag (YOLO mode)`.
- The shell tool: the model itself reported `run_shell_command` as "not registered" in this session and silently
substituted a read-only `glob` call instead — no approval prompt, no classifier call, no system warning printed
(unlike the MCP case), across two separate clean runs.
**Conclusion: one-shot headless `qwen <prompt>` invocations don't exercise Auto Mode's classifier at all for
approval-requiring tools** — they're declined or silently rerouted before the classifier ever gets a request.
The classifier only fires in a genuinely interactive session, where it substitutes for the human's live approval
decision. This wasn't previously documented anywhere in this repo and is worth keeping in mind: headless qwen-code
testing is not a valid way to probe classifier behavior, live or otherwise. (Not investigated further: whether
`qwen serve`/`--input-format stream-json` headless-agent modes behave differently — plausible, since they're
built for exactly this kind of automation, but out of scope for this pass.)
### Direct backend test: real classifier latency at realistic token counts
Given headless qwen-code couldn't drive this, sent shaped classifier requests straight to
`http://proxy-ai.home/v1/chat/completions` (model `qwen3-4b//models/Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf`,
confirmed present in `GET /v1/models`) using a temporary scoped API key, mimicking the `{shouldBlock}`
JSON-verdict shape and the `MAX_TRANSCRIPT_MESSAGES=40` / `MAX_HISTORICAL_ACTION_CHARS=4000` structure this
repo's own `fast-model-choice.md` already read out of qwen-code's `classifier-transcript.ts` source. Five calls,
in order:
| # | Prompt tokens | `cached_tokens` | Wall time | Notes |
|---|---|---|---|---|
| 1 | 1,000 | 3 | 2.24s | Small prompt, genuinely fresh — healthy baseline. |
| 2 | 51,234 | 51,233 | **64.21s** | First send of a large synthetic worst-case transcript (~40 highly self-similar 4K-char "historical action" blocks). Near-total cache hit reported, yet still the slowest call — see caveat below. |
| 3 | 51,234 | 51,233 | 0.07s | **Identical repeat of #2.** Same `chatcmpl-...` id as #2 came back — this is OmniRoute short-circuiting an exact-duplicate request via a proxy-level response cache, not fresh inference. Confirms #2/#3's `cached_tokens` field is not a reliable proxy for wall-clock latency on its own. |
| 4 | 1,000 | 3 | 0.03s | Identical repeat of #1 — same id, same response-cache short-circuit. |
| 5 | 30,958 | 919 | **28.66s** | Fresh, non-repeated worst-case-shaped transcript (different random content, no internal self-similarity to trigger cache effects). Mostly-uncached (919/30,958) — this is the clean data point. |
Call #5 is the one to trust: **~31K genuinely-fresh prompt tokens took 28.7 seconds** on the current
`--n-gpu-layers 28` (of 36) / `--cache-type-k/v q4_0` / `--parallel 1` configuration, with the backend otherwise
idle and healthy (no hang in progress). Extrapolating that rate to the repo's own documented worst case (a real
15,116-token call observed live per `fast-model-choice.md`, and a theoretical ceiling around 40-50K tokens per
`classifier-transcript.ts`'s limits) puts a genuine worst-case classifier call at **roughly 30-65 seconds of
normal, non-hung processing time** — consistent with call #2's 64.21s, even though that call's own cache
metadata is too muddied by internal prompt self-similarity to use as a second clean sample.
**This directly overlaps both binding timeouts**: qwen-code's own client-side classifier stage timeout
(`stage1Ms`/`stage2Ms`, `60000` each in the Windows-side `settings.json` observed this session, `30000`/`60000`
in the WSL-side one) and `OMNIROUTE_DIRECT_HEADERS_TIMEOUT_MS`'s 30-second-per-attempt window documented above.
A worst-case classifier call landing in the 30-65s range will **routinely** trip one or both of these timeouts
on its own, with the backend never having hung at all — the exact same 499/504/"Request aborted" shape as the
GPU-hang hypothesis produces, but from an entirely mundane, deterministic cause: **the classifier's current
configuration is simply too slow for the request sizes qwen-code's own classifier-transcript design allows.**
### What this changes
This doesn't rule out ROCm/legacy-rocm-build#6630 — the 27B model's 48-minute total outage (zero successes, not
just slow ones) doesn't fit a "just slow" explanation, and remains best matched by a real GPU hang. But it does
mean **the classifier's own recurring failures (the pasted-table evidence) very plausibly have a second,
independent, non-probabilistic cause that a healthcheck/restart-on-hang design wouldn't fix at all** — restarting
a classifier that's merely slow-but-working at worst-case load just interrupts a call that would have succeeded,
and would fire repeatedly under normal peak usage, not just during a rare hang. Any fix that only targets "detect
and recover from an unresponsive GPU" leaves this second failure mode untouched. Two independent levers worth
weighing before finalizing a scope: raising the classifier's own timeouts to match its real worst-case latency
(cheap, immediate, but does nothing for actual hangs), and/or speeding up the classifier itself (full GPU offload
if VRAM allows, a faster quant, or capping the transcript size client-side) to bring worst-case latency back
under the existing timeouts.
**Not investigated in this pass**: whether call #2's 64.21s (vs. call #5's extrapolated ~45-48s at a similar
token count) reflects genuine non-linear slowdown at the very largest context sizes, real concurrent contention
from other production traffic sharing the same `--parallel 1` slot during the test, or is just noise from a
single sample each — worth a few more clean, uniquely-content, worst-case-sized calls at different times of day
before treating either number as precise.
@@ -0,0 +1,216 @@
# OmniRoute's builtin memory tools silently hijack qwen-code's classifier tool-call, not a model or GPU problem
**Date:** 2026-09-15
**Verdict:** The `"Classifier stage 1 unavailable"` / `"Auto Mode couldn't classify this action"` failures are **not**
a GPU hang, not a timeout, and not a Qwen3-4B quality problem. Confirmed directly from a live debug log: the fast
model (`qwen3-4b//models/Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf`) *is* being used (`stage=fast` in every classifier
log line), and it responds well within its timeout (18.7s against a 30-60s budget). The failure is
`"Error: Invalid side query response: params must have required property 'shouldBlock'"` — a **schema-validation
failure on an in-time response**. Root cause, confirmed directly against OmniRoute's own source
(`open-sse/handlers/chatCore/memorySkillsInjection.ts`): **OmniRoute silently appends its own builtin memory tools
(`memory_save`/`update`/`search`/`delete`) to every non-streaming chat completion's `tools` array**, whenever
memory is enabled for the calling key — regardless of what tools the caller declared. qwen-code's classifier forces
`tool_choice: ANY` (call *some* tool, not a specific one) so it can get a structured `respond_in_schema` JSON
response. With OmniRoute's extra tools spliced in, the small model sometimes picks the injected `memory_save` tool
instead — and since qwen-code's client only extracts the classifier's answer from a `respond_in_schema` function
call (not from a stray `memory_save` call, even if the answer also happens to be present as plain text), the
result validated against `STAGE1_SCHEMA` is empty, producing exactly the observed error.
## The debug-log evidence
Captured directly from a `-d` (debug) qwen-code run, `C:\Users\aerli\.qwen\debug\886d00eb-...txt`:
```
21:09:56 [DEBUG] [CLASSIFIER] ALLOW stage=fast tool=mcp__omniroute-search__search durationMs=15412
21:10:28 [WARN] [CLASSIFIER] failUnavailable stage=fast durationMs=18727 reason="Classifier stage 1 unavailable" cause="Error: Invalid side query response: params must have required property 'shouldBlock'"
```
Both lines are tagged `stage=fast` — qwen-code's own internal label confirming the classifier used the configured
fast model both times, settling a live question this session raised about whether the classifier was silently
falling back to the main 27B model. It wasn't. The second call's 18.7s duration is comfortably inside this
deployment's configured `stage1Ms` (30000-60000ms depending on install) — this was not a timeout.
## Reproduced directly
Sent the exact same request shape qwen-code's `classifyAction()`/`generateJson()` builds — a forced tool call to a
synthetic `respond_in_schema` function with `STAGE1_SCHEMA` (`{required: ["shouldBlock"], properties: {shouldBlock:
{type: "boolean"}}}`) as its only declared tool, `tool_choice: "required"` — directly against
`POST /v1/chat/completions` on this deployment (model `qwen3-4b//models/Qwen3-4B-Instruct-2507-UD-Q4_K_XL.gguf`).
The very first response:
```json
{
"message": {
"content": "{\"shouldBlock\": true}",
"tool_calls": [{
"type": "function",
"function": {
"name": "memory_save",
"arguments": "{\"key\": \"tool_call_review\", \"content\": \"web_fetch call to https://www.swfte.com/ai/leaderboard was blocked due to potential data exfiltration or unauthorized external access.\", \"type\": \"factual\"}"
}
}]
},
"tool_results": [{ "output": "{\"success\":true,\"memory\":{\"id\":\"84389721-...\", ...}, \"message\":\"Memory saved successfully\"}" }]
}
```
`memory_save` was never declared in the request's `tools` array — only `respond_in_schema` was. OmniRoute added it
server-side, the model called it instead of (or alongside) the intended tool, and OmniRoute **auto-executed it**
(`tool_results` shows a real memory record was created, with a UUID and timestamp — this isn't inert). The correct
`{"shouldBlock": true}` answer is sitting right there in `content`, but qwen-code's `generateJson()` only ever
looks for it inside a `respond_in_schema` function call (`functionCalls.find(call => call.name ===
"respond_in_schema")`); when that's absent it falls through to a raw-text JSON parse of `getResponseText(result)`
— and OpenAI-client conventions generally don't populate a response's plain-text field when `finish_reason` is
`tool_calls` rather than `stop`, so that fallback likely returns nothing, yielding `{}` against a schema that
requires `shouldBlock`. This is a single confirmed repro, not a guaranteed-every-time reproduction — the injected
tool doesn't win every time (an immediate identical follow-up request returned an OmniRoute-cached copy of the same
response, not a fresh sample — see the cache caveat in
[`omniroute-direct-response-timeout-outage-2026-09-15.md`](./omniroute-direct-response-timeout-outage-2026-09-15.md)),
but it reproduces the *exact* failure shape from the live debug log on the first genuine attempt.
## Root cause, confirmed in OmniRoute's own source
[diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute) —
`open-sse/handlers/chatCore/memorySkillsInjection.ts`:
```ts
if (memoryOwnerId && memorySettings?.enabled && body.stream !== true) {
// Server-side builtin memory tools (memory_save/update/search/delete) are
// executed by the gateway's tool-call interception, which runs only on the
// non-stream path. Stream clients (opencode etc.) execute tools client-side,
// so for them these tools would be announced but never executed; they should
// use the MCP memory tools (omniroute_memory_*) instead.
const existingTools = Array.isArray(body.tools) ? body.tools : [];
...
const memoryTools = buildMemoryToolsForProvider(...).filter(tool => !existingToolNames.has(name));
if (memoryTools.length > 0) {
body = { ...body, tools: [...existingTools, ...memoryTools] };
}
}
```
This runs unconditionally for any non-streaming request from a key with memory enabled — there is no exemption
for a caller that already set `tool_choice` to force a *specific* tool. qwen-code's classifier is exactly this
case: a single-purpose, forced-`ANY`, non-streaming tool call, which is precisely the shape this injection logic
was not written to avoid interfering with.
`src/lib/memory/settings.ts` confirms `enabled: false` is the *default* — memory is off by default in a fresh
OmniRoute install specifically because of injected-context cost, per its own comment:
> "Off by default: enabling memory injects up to `maxTokens` (~2k) of retrieved context into every chat request,
> which is billed — a surprising cost for new installs... Opt in explicitly via Settings → Memory... Per-request
> opt-out is also available via the `x-omniroute-no-memory` header."
This deployment has memory enabled (confirmed live by the reproduction above), which is presumably a deliberate
choice for other workflows (chat memory across sessions) — but it has an undocumented-to-this-repo side effect on
any caller using forced-tool-call classification.
## What would fix this
Two per-target exclusions were checked live against this deployment and confirmed **not to exist**:
- **Per-API-key memory override**: `GET /api/keys` was fetched directly (the temporary key handed to this session
turned out to carry admin access, well beyond the plain `/v1` workload scope its name implied). Every key's full
field list was inspected — `noLog`, `scopes`, `allowedModels`, `rateLimits`, `disableNonPublicModels`, etc. — with
no memory-related field anywhere.
- **Per-model/connection override**: `GET /api/providers/<id>` for the classifier's own connection
(`qwen3-4b`, id `b78ceb4c-52f8-47ae-b245-483baa6e3fc2`) was fetched directly. `providerSpecificData` (`prefix`,
`apiType`, `baseUrl`, `nodeName`, `timeoutMs`, `apiKeyHealth`) has no memory field either — consistent with the
source: `memoryOwnerId` is resolved purely from the *calling key* (`resolveMemoryOwnerId(apiKeyInfo)`), before
OmniRoute has even picked a provider, so it can't know or care that this particular request targets the
classifier model specifically.
**The fix that was actually available and is now applied**: `x-omniroute-no-memory`, OmniRoute's own per-*request*
opt-out (not per-key or per-model), confirmed end-to-end and traced through both sides:
- OmniRoute's handling, confirmed directly in `open-sse/handlers/chatCore.ts` and its own test suite
(`tests/unit/no-memory-header.test.ts`): `memoryOwnerId = isNoMemoryRequested(headers) ? null : resolveMemoryOwnerId(...)`
— a null owner id short-circuits *both* branches in `injectMemoryAndSkills` (context injection and tool
injection). The test suite gives the exact accepted values: `"true"`, `"1"`, `"yes"` (case-insensitive on both
the header name and value); `"false"`/`"0"`/`"no"`/empty do not trigger it.
- qwen-code's support for sending it, confirmed against the installed bundle, *not* just the docs: `modelProviders.
openai[].generationConfig.customHeaders` (documented at
[model-providers](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/model-providers/)) flows into
`DefaultOpenAICompatibleProvider.buildClient()` (`chunk-CXTPVBFA.js`), which passes it straight into the
underlying `OpenAI` SDK client as `defaultHeaders` — applied to every request made through that one model entry,
and *only* that entry (confirmed this is the generic OpenAI-compatible-chat client, the same one the classifier's
`apiType: "chat"` connection uses — not Anthropic- or Responses-API-specific plumbing).
**Applied**, 2026-09-15: added to the `qwen3-4b-classifier` entry in the Windows-side `~/.qwen/settings.json`
(`C:\Users\aerli\.qwen\settings.json`), inside its `generationConfig`, alongside the existing `contextWindowSize`
and `extra_body`:
```json
"customHeaders": { "x-omniroute-no-memory": "true" }
```
Scoped to this one model entry only — the main `qwen3.8-27b-local` connection's `generationConfig` is untouched,
so its own memory-context behavior (if any is relied on elsewhere) is unaffected. qwen-code's own
`[MODEL_PROVIDERS_HOT_RELOAD]` settings watcher (confirmed present in this session's debug log) should pick this
up on the already-running session without a restart. **Not yet verified live** — the next classifier failure (or a
deliberate repro, per the "Reproduced directly" section above) should confirm no `memory_save`-shaped tool call
appears in the response once this is in effect.
- **Remaining fallback, if the header approach doesn't hold up**: disable memory globally for this deployment
(`PATCH /api/settings/memory`, `enabled: false`, or Settings → Memory in the dashboard) — blunt, but confirmed to
work by definition since `enabled: false` is every fresh install's default.
- **Also worth doing regardless**: file this upstream with OmniRoute. Their own code already special-cases one
caller type (streaming clients) right next to this injection logic; a similar exemption for a caller that already
set `tool_choice` to force one specific tool would be a clean fix on their end that doesn't depend on every
client remembering to send an opt-out header.
- **Not a fix, and not the problem**: nothing on the classifier-model or llama.cpp side. Qwen3-4B-Instruct-2507
correctly produced the right answer (`{"shouldBlock": true}`) in the one reproduction captured here — the model
was never at fault.
## Scope note
This session's earlier hypothesis that the 27B model's 48-minute total outage
([`omniroute-direct-response-timeout-outage-2026-09-15.md`](./omniroute-direct-response-timeout-outage-2026-09-15.md))
was caused by a ROCm/gfx1201 GPU hang is set aside here per explicit direction, not retracted — that was a
different incident (zero successes for 48 straight minutes, a shape this memory-injection bug doesn't produce) and
this finding doesn't bear on it either way.
## Sources
- Live debug log, `C:\Users\aerli\.qwen\debug\886d00eb-5b2b-4d84-b1ef-60909f75eec2.txt` (this session, 2026-09-15)
- Direct reproduction against this deployment's `POST /v1/chat/completions` (this session, 2026-09-15)
- Live `GET /api/keys`, `GET /api/providers`, `GET /api/providers/b78ceb4c-52f8-47ae-b245-483baa6e3fc2`,
`GET /api/settings/memory` against this deployment's OmniRoute instance (this session, 2026-09-15) — confirmed no
per-key or per-connection memory field exists in either schema
- [diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute) —
`open-sse/handlers/chatCore/memorySkillsInjection.ts`, `open-sse/handlers/chatCore.ts` (the
`isNoMemoryRequested`/`resolveMemoryOwnerId` branch), `src/lib/memory/settings.ts`, `src/lib/memory/injection.ts`,
`open-sse/mcp-server/tools/memoryTools.ts`, `tests/unit/no-memory-header.test.ts` (exact accepted header
name/value set)
- [Qwen Code docs — Model Providers](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/model-providers/)
(`customHeaders` field, documented under `generationConfig`)
- Installed qwen-code bundle — `chunk-N7VWZDWW.js`, `chunk-HBU7EKY4.js` (`classifyAction`, `runSideQuery`,
`resolveDefaultModel`, `generateJson`, `resolveFastModelSelector`, `getFastModel`) and `chunk-CXTPVBFA.js`
(`DefaultOpenAICompatibleProvider.buildHeaders()`/`buildClient()`, confirming `customHeaders` reaches the actual
OpenAI SDK client as `defaultHeaders` for the plain chat-completions path the classifier uses) — all read
directly from the bundled (unminified variable names) source, not inferred from docs alone
- Applied fix: `C:\Users\aerli\.qwen\settings.json`, `qwen3-4b-classifier` entry's `generationConfig.customHeaders`
(this session, 2026-09-15)
## Confidence / uncertainty summary
- **High confidence**: the fast model is genuinely used for classification (`stage=fast` in qwen-code's own debug
log, both on success and failure); the failure is a schema-validation error on an in-time response, not a
timeout (18.7s duration, explicit error text); OmniRoute's `memorySkillsInjection.ts` unconditionally injects
builtin memory tools into non-streaming completions for any memory-enabled key, with no exemption for
forced-single-tool callers (read directly from source); no per-key or per-model/connection memory override
exists in this OmniRoute version (confirmed by reading the complete live schema of both, not by absence of
documentation); `x-omniroute-no-memory: true` is a real, working per-request opt-out on OmniRoute's side (its
own test suite) and is reachable from qwen-code via `modelProviders.openai[].generationConfig.customHeaders`,
traced to the exact HTTP client the classifier's connection type uses (not inferred from docs alone — confirmed
against the bundled source's actual header-merging code).
- **Medium confidence**: that this exact tool-injection mechanism explains the *specific* production failures seen
earlier in this session's testing (the reproduction matches the failure shape and the source confirms the
mechanism exists and applies to this call pattern, but the live debug-log failure itself wasn't captured
mid-flight with response inspection — only its aftermath, the error message).
- **Low confidence / not verified**: the exact conditions under which the model picks the injected tool over the
intended one (one clean reproduction on the first attempt, not a characterized hit rate — the failure may not be
deterministic, so the `customHeaders` fix should still be watched rather than assumed to have fully resolved it
on the strength of this write-up alone); whether the applied `customHeaders` fix has been confirmed live yet
(not as of this writing — see "Applied" above).
@@ -0,0 +1,60 @@
# OmniRoute's "non-ping SSE" first-token deadline — a different timer than `STREAM_IDLE_TIMEOUT_MS`
**Date:** 2026-09-10
`STREAM_IDLE_TIMEOUT_MS` was raised to 180000 on 2026-09-09 (see docker-compose.yml's `omniroute`
service) specifically to give contended `llama-server` prefill room to produce a first token. It didn't
work: the very next morning, qwen-code sessions against `qwen3.8-27b-local` still hit repeated
```
Stream produced no non-ping SSE event within 95000ms
```
(and once at 115000ms) — both well under the 180s the compose fix set, and well under the connection's
own `providerSpecificData.timeoutMs: 1200000` (confirmed live via `GET /api/providers/<id>`). Neither of
those settings bounds this failure.
## Root cause
Per OmniRoute's own docs (`docs/reference/ENVIRONMENT.md`, "Timeout Settings" section) and a maintainer
reply in [diegosouzapw/OmniRoute#10602](https://github.com/diegosouzapw/OmniRoute/discussions/10602):
| Variable | Default | Governs |
|---|---|---|
| `REQUEST_TIMEOUT_MS` | 600000 (10 min) | Overall upstream request budget. **The first non-ping SSE event's deadline inherits this one.** |
| `STREAM_IDLE_TIMEOUT_MS` | 120000 (2 min) | Max gap between *successive* SSE chunks once streaming has already started — does not govern the wait for the first chunk. |
| `STREAM_PING_INTERVAL_MS` | 30000 (30s) | How often OmniRoute emits its own keepalive pings on the stream — these explicitly do not count as "non-ping" events, so they can't rescue a request against the first deadline. |
So the 2026-09-09 fix tuned the wrong timer for this failure mode: `STREAM_IDLE_TIMEOUT_MS` only matters
once `llama-server` has already emitted something. The "no token at all yet" case — exactly what a large
compact-prompt prefill on a contended local model produces — is bounded by `REQUEST_TIMEOUT_MS` instead.
The observed 95000ms/115000ms figures are also *not* `REQUEST_TIMEOUT_MS`'s raw 600000ms default: OmniRoute
computes the first-event deadline as **remaining budget**, not a flat timer — `REQUEST_TIMEOUT_MS` minus
time already spent in OmniRoute's own request-queue/retry/cooldown cycle (`requestRetry: 3`,
`connectionCooldown.apikey.baseCooldownMs`, provider breaker) before the request was actually dispatched
to `llama-server`. Confirmed live via `GET /api/settings``resilienceSettings` on this deployment. Most
of the 10-minute default budget was being burned by retries before the final attempt even started.
## Fix
Set `REQUEST_TIMEOUT_MS` explicitly, generously — applied in docker-compose.yml as
`OMNIROUTE_REQUEST_TIMEOUT_MS` (default 1800000 / 30 min), same pattern as
`OMNIROUTE_STREAM_IDLE_TIMEOUT_MS`. This doesn't replace the 2026-09-09 `STREAM_IDLE_TIMEOUT_MS` fix —
that one still matters for mid-stream stalls after generation has started — it addresses the separate
"nothing has arrived yet" case that fix didn't cover.
Raising `REQUEST_TIMEOUT_MS` buys headroom; it doesn't address *why* prefill on a 50K+ token compact
prompt can take that long in the first place. `llama-server` had no `--cache-reuse` flag set — every
request reprefilled its full prompt from scratch even when most of a conversation's prefix was unchanged
from the previous turn. Added `--cache-reuse 256` (docker-compose.yml) so llama.cpp reuses cached KV for
any matching ≥256-token chunk via KV-shift instead of reprocessing it, which is the actual fix for
compact-prompt prefill time — the timeout bump above is a safety margin around it, not a substitute.
## Sources
- [diegosouzapw/OmniRoute](https://github.com/diegosouzapw/OmniRoute) — `docs/reference/ENVIRONMENT.md`
("Timeout Settings"), [Discussion #10602](https://github.com/diegosouzapw/OmniRoute/discussions/10602)
- Live `GET /api/providers/<connectionId>`, `GET /api/settings`, `GET /api/resilience` against this
deployment's OmniRoute instance (2026-09-10)
- [`docs/research/omniroute-account-semaphore-timeout.md`](./omniroute-account-semaphore-timeout.md) — the related-but-distinct 30s semaphore/429 investigation
+1
View File
@@ -233,6 +233,7 @@ docker compose build --pull
echo "==> ensuring models are downloaded (skips already-present files)"
docker compose --profile tools run --rm downloader
docker compose --profile tools run --rm downloader-fast
docker compose --profile tools run --rm downloader-classifier
docker compose --profile tools run --rm downloader-comfyui
echo "==> bringing up omniroute"