Root cause of the multi-day degeneration hunt, operator-confirmed: the AEON
NVFP4 W4A4 quant (sakamakismile/Qwen3.8-27B-AEON-ULTIMATE-UNCENSORED-NVFP4,
full W4A4 incl. attention) went degenerate ~15-20% of generations in real
multi-turn use and forced regenerates. MTP, prefix-caching, and the gateway
all merely AMPLIFIED it, which is why MTP-off, APC-off, and the vLLM #51113
fix each 'helped' a synthetic probe without fixing it -- three plausible
false root-causes, each passing one clean run then failing in real use.
The fix was the WEIGHTS: the in-house JonathanColetti/Heretic mixed
NVFP4+FP8 build (qwen38-27b-uncensored-nvfp4-mixed, FP8 attention not W4A4,
same base, same MTP) is coherent through long multi-turn with MTP ON. W4A4
*attention* was the defect; FP8 attention is not.
This commit:
- GEN_MODEL -> the mixed FP8-attn build (primary gen until DavidAU 3.8 lands)
- GEN_IMAGE pinned to vllm/vllm-openai:nightly-311b3513... (v0.27.2rc1.dev150,
carries #51113; pinned by sha so it does not drift on the next pull)
- AEON weights PURGED from /tank (no-good), safety-checked not-in-use first
- playbook 3.8: the stochastic-W4A4-degeneration lesson + isolate-weights-early
+ do-not-declare-a-fix-from-one-probe (it validated three non-fixes)
AEON is re-pullable from HF if ever needed, but the operator ruled it no-good.
The qwen3_5_mtp corruption (playbook 3.7) is gated on MTP x prefix-caching
TOGETHER (vllm#43559 / #47194), per both cross-frontier peers. Disabling
prefix caching (--no-enable-prefix-caching; vLLM V1 defaults it ON, so the
explicit --no- form is required) forces the GDN cache into a mode where the
partial-accept align-path bug is inert, so MTP can stay on.
Verified on our stack (AEON W4A4): MTP on + prefix-caching off -> the 7-turn
varied series stays coherent through 3.9k tokens, zero cross-turn bleed, at
104.6 tok/s / 53.6% acceptance -- the FULL MTP speedup restored (vs ~half
with MTP off), losing only prefix-cache reuse. All 7 aliases route.
Ruled out on the way: num_speculative_tokens=1 (corruption is
depth-independent, n=1 and n=2 both corrupt); switching to SGLang (vLLM /
SGLang / llama.cpp mainline all share the architectural GDN-rollback bug).
Proper upstream fix (#51113) is in main / v0.27.2rc0 only, not stable, so we
hold at APC-off rather than jump the fleet gateway to an RC.
Supersedes the MTP-off config from 7bd38b3.
The single hardest bug of the night, and invisible to the existing
acceptance gate: a LOADED, healthy-accepting MTP head still corrupts
Qwen3.8-27B multi-turn output past ~2k cumulative tokens (length collapse +
cross-turn content bleed), while single-turn is perfect. Model-independent
across all three of our Qwen3.8 quants; Qwen3.6 on the same qwen3_5_mtp
method is clean; disabling MTP fixes it. New rule: gate MTP on a multi-turn
coherence probe, not just single-shot acceptance.
Quants are hard-fought and we keep re-paying for the same lessons. A survey
found quant knowledge scattered across 18 files in four trees, with three
documents having independently discovered and recorded overlapping
"landmines" sections — and one of them now actively misleading.
Adds docs/pfi/model-quantization-playbook.md as the single home for the
TRANSFERABLE lessons, with per-model artifacts demoted to worked examples
that link up to it. Contents:
- scheme decision table, incl. that a literal "W4A8" NVFP4 checkpoint is
unservable on vLLM (two legal activation settings, FP8 is not one)
- the reference mixed-precision recipe and the three parts of it that are
load-bearing and easy to drop
- the recurring landmines, ordered by cost: the loader-class trap
(rediscovered THREE times), the three separate ways to lose the MTP head,
toolchain deadlocks, vision configs, memory/device placement
- pipeline shape: prove targets before spending GPU time; mandatory
post-steps that verify rather than assume
- the acceptance gate, and the three ways measurement has lied to us —
prefix caching faking both speed metrics, prompt_logprobs going uniform
under speculative decoding, and a 0600 .env making compose silently no-op
- hardware/co-residency, including that a SMALLER model can starve its
neighbour because gpu-memory-utilization is a fraction of the whole card
- a superseded-claims table, and measured negatives not to re-chase
The superseded table earns its place immediately: the heretic2 runbook tells
readers to use modelopt because "compressed-tensors can't load the BF16 MTP
head, 0% acceptance". That symptom was real but the cause was not the format
-- it was the missing re:^mtp.* ignore entry. compressed-tensors gives
47.7-83.2% acceptance in production. A fresh session following that doc would
be sent down the modelopt path that current memory calls dependency hell, so
the runbook now carries a stale-warning header pointing here.
Wires discovery: an orientation.md "Where to look for what" row, pointers
from the gen-seat / heretic2 / mistral artifacts, and a CLAUDE.md maintenance
rule so the playbook gets fed instead of going stale -- model-agnostic
lessons land in the playbook, model-specific ones stay put, and a wrong
claim earns a dated superseded row rather than a silent edit.
Motivated by Qwen3.8 having just released: the next model swap will need a
requant, and this is what that session should read first.
56KB deep-research report on thinking-capable eRP finetunes 15-30B, weighted for
spatial/state coherence, targeting RTX PRO 6000 Blackwell (sm_120) NVFP4. Preserved
from an ephemeral Booth (gecko-65) into durable reference for the quant decision.
Brokkr independent verify clean (maxdiff 0.000000, no split). R42 v13
acceptance gate PASSES first time in its history: main+kb 56/90->90/90,
evictions 33->0. A2 control torn down. A3 throughput characterized at
~34 req/s (graceful queueing), with A4/util-bump/replica as levers.
A3 now backs the prod reranker alias but was launched --restart no;
docker update to unless-stopped so an ana-ml2 reboot can't silently
break the alias. Full compose-service promotion tracked as a follow-up
in the selection ledger.
The incumbent Qwen3-Reranker-0.6B was measured actively harming 80/90
fleet queries on main+knowledge_base (and inverting the bare-name region
behind Worldtree #389) — no-reranker beat it 89/90 vs 56/90. Brokkr's R43
bake-off selected BAAI/bge-reranker-v2-m3 (A3): 90/90 top-10, mean rank
0.19, multilingual (XLM-R), ~1.2 GB lighter than the incumbent.
Control arm (A2 = same Qwen weights, seq-cls head) scored identical to the
incumbent, proving the fault is a training prior, not the serving head —
which cancelled the expensive Qwen3-4B arm before it cost a GPU seat.
Cutover boundary 2026-08-06T17:37:48Z. The qwen3-reranker alias and the
:8002 backend are retained for one-edit rollback. Adds the process audit
trail at docs/pfi/reranker-selection-ledger.md.
The live gateway config has served char-rp-reasoning as deckard-pkd-27b (:8018)
since the 2026-07-08 A/B; the standalone doc had frozen on QwQ-RpR-v4. Corrects
seat 4 (backend + samplers + server-side DRY/reasoning-budget notes).
Also snapshots session state in persistent-memory.md: phantom-qwen verified
already-clean, ana-docker docker log-cap (logrotate copytruncate, no bounce),
and the granite→gen memory_extractor bind live on demo+personal.
Add §9 "PFI LiteLLM Gateway — Deployed Sampling Defaults": the live fleet
sampling table (granite/qwen/judges/GLM) with provenance, overrideable-default
semantics, the GLM API-accepted-subset caveat, and the research-confirmed temp-0
rationale for granite + image-judge. Accepts the dvalin-smithy-dev recommendations
as deployed. §§1-8 vendor reference left intact.
Replaced the 9-month-stale 'Last Updated: 2025-07-14' line with a
status disclaimer — this is KB-derived advisory material, not
something we maintain in lockstep with code. Tracer-date claim was
implying a freshness contract we don't fulfill. Found via
/tend-docs.
Same anti-pattern as the deleted model-list.md — a hardcoded snapshot
of mutable config that's guaranteed to drift. Replaced the 15-row
table with a one-liner pointing at stacks/llama-swap/conf/config.yaml
(the canonical source) and the live /v1/models HTTP endpoint. Found
via /tend-docs.
Self-reported "Synchronized with llama-swap config.yaml on 2025-07-18"
— 9 months stale. Canonical model truth is stacks/llama-swap/conf/config.yaml;
the static snapshot was guaranteed to drift. No historical value (not
an ADR, post-mortem, or migration runbook).
Found via /tend-docs.
Second pass on docs/ cleanup (item #15 in STATUS.md):
- pfi/chromadb-setup.md: deleted. References configs/pfi-ana/... and
scripts/setup-chromadb.sh, neither of which exist in this repo
(artifacts of an earlier project layout). ChromaDB is already live
per docker-stack.md; the operational truth lives there.
- pfi/docker-stack.md: removed the cross-link to the deleted file and
pulled the bit of useful content from it (auth-token generation +
client Settings example) into the inline ChromaDB section.
- pfi/vm-102-matrix-{synapse,appservice}.md: stripped the YAML
frontmatter. The `path:` values pointed at docs/pfi-ana/... which
doesn't exist in this repo; no toolchain consumed the metadata.
- README.md: tree updated to reflect the deletion.
VM-102 docs kept separate by design — each is right-sized; merging
would push past the ~500-line guideline.
Network probes (no web admin, Debian SSH banner, only file-server ports
open) show 10.250.50.50 is vanilla Debian 12 with hand-configured NFS/SMB,
reprovisioned from the original TrueNAS SCALE install. Update stack
comments, README storage notes, Backrest description, proxmox-vms.md
entry for VM 100, and the restic configs intro to match.
Cross-site sync plan simplifies to plain rsync over SSH on both sides —
no appliance-specific tooling needed.
Captures the full workspace state built up to this point:
- CLAUDE.md + README.md describing conventions and the four-host fleet
(ana-ml2, ana-docker, nh3-docker, esh-docker-vm).
- Per-host notes under servers/<host>/ with ssh-target fallback files
and latest system-details snapshots (two in-compose credential leaks
scrubbed; the upstream compose files still need to move those to .env).
- scripts/: server_inspect.sh (read-only remote diagnostic),
refresh-server-info.sh (dir-driven discovery + snapshot capture with
validation warnings), add-host.sh, sync-stacks.sh (pull
compose/conf trees), deploy-stack.sh (push with per-file diff + prompt).
- stacks/: canonical compose for backrest, beszel, dozzle, llama-swap,
rest-server-ana, rest-server-nh3, vllm-qwen3, plus the retired
infinity reference. All use the .env-driven + traefik-net + homepage
label pattern.
- configs/restic/ana-docker/: first resticprofile config + pre-backup
hook (Synapse pg_dump, Seafile mysqldump, Vaultwarden SQLite); templates
for the other three hosts to come.
- docs/pfi/: general infrastructure reference carried over.
- .gitignore excludes .env, stacks-mirror/, and assorted secret/state
filenames to prevent re-leaks on later commits.
vh