Operator approved after real-use testing. The experimental standalone
container is retired and stacks/mog-sec is canonical again, with
restart: unless-stopped so the configuration survives a reboot.
Cutover verified against the container it replaces: KV pool 526,617 tokens
at 1.10x concurrency, identical; zero restarts; both gateway aliases
serving; DFlash2 confirmed drafting at k=7 with 231 draft tokens over 33
drafts; vision working at 2048x2048.
One variable was deliberately dropped rather than carried over. The previous
stack hardcoded PYTORCH_CUDA_ALLOC_CONF=expandable_segments:True, the
validated container never set it, and the quant playbook records
expandable_segments corrupting retained tensors in another context. The
compose now defaults it empty via MOG_ALLOC_CONF. Promoting the stack as it
stood would have shipped a variable the tested configuration did not have.
The speculative config moves into a single MOG_SPEC_CONFIG carrying the
whole JSON, because the two shapes are not interchangeable: dflash requires
a model pointing at the drafter and MTP must not have one, so a
method-plus-tokens template cannot express both. Also parameterised:
MOG_DRAFT_MODEL, MOG_MM_PROCESSOR_KWARGS, MOG_MAX_NUM_BATCHED_TOKENS.
The mm-processor image cap is now mandatory rather than incidental. The
model's own preprocessor declares 4096x4096, which expands to 16384 image
tokens and kills startup on builds that enforce the image-token count check.
Adds the .env.example this stack never had, carrying the measured rationale
for each value and the one-line rollback.
Operator ruling: the multi-turn degeneration lives in the un-fixed vLLM, not
in the weights. The hypothesis that sec's stock-graft MTP head causes it is
withdrawn.
Two failures produced it. First, a false dichotomy treated as a deduction:
having verified gen and sec run an identical engine, I concluded config was
eliminated and therefore the weights were responsible. That does not follow.
An engine bug present in both seats is not exonerated by the seats being
identical; it only means the engine cannot explain a difference between
them. It can still explain the failure.
Second, and more instructive, the difference being explained may not exist.
The premise was a single operator observation made during a session with
many concurrent changes. That cannot carry a causal claim, and it became the
load-bearing support for a root-cause narrative it could not hold.
The same caveat now attaches to the coherent-to-10k observation on the new
build: same n, same uncontrolled conditions, opposite direction. The
comparison is weak at both ends, so the file no longer presents either
sighting as a result.
What survives as measured fact is unchanged and still recorded: sec's MTP
head is byte-identical to the uncensored base across all 15 tensors, gen's
was abliterated in-band, and acceptance differs slightly. None of that is
shown to cause degeneration.
Adds the generalisable lesson: an observation made while many things are
changing cannot support a causal conclusion. It is the inverse of the
warning already in the gen-seat compose file, which guards against trusting
a negative result from a synthetic probe; this guards against trusting a
positive sighting from an uncontrolled session.
Records the 2026-08-22 session with measured results, hypotheses, and wrong
turns explicitly separated -- the operator held this back while it was in
flight specifically so conjecture would not enter the record as fact.
MEASURED. DFlash2 works on an abliterated + NVFP4 compressed-tensors target
on Blackwell sm_120, which the model card does not claim (it tests stock
BF16 on H200). gen 2.753 -> 3.254 accepted tok/forward and 114.9 -> 131.9
tok/s; sec 2.676 -> 3.252 and 110.5 -> 130.0. The drafter is model-agnostic
across two different finetunes to 0.06%, but is EAGLE3-style coupled to its
target's hidden states, so the weights file is shareable while the 3.85 GB
of VRAM is per-seat.
The k=7 MTP control is the load-bearing result: raising MTP depth improves
acceptance and collapses throughput to 74.0 tok/s, because a single-module
head run autoregressively costs one forward pass per draft token. Without
that control the obvious recommendation would have been wrong.
CONFOUNDED. sec no longer degenerates at 2k, but the engine advanced 259
commits and the drafter changed at the same time. Isolating it means running
MTP k=3 on the new build. Also recorded: #51113 is present in both builds
and is therefore necessary but insufficient, since sec ran it and still
degenerated.
HYPOTHESES, labelled as such: that sec's stock-graft MTP head causes the
degeneration, and that NVFP4 explains the gap against published acceptance
figures. Neither is proven.
WRONG TURNS, recorded so they are not re-derived: version strings are not
lineage, Docker Hub push timestamps are not source freshness, and the claim
that 1M context needs YaRN absent from config is false for the sec quant.
Operationally important: sec is serving from a standalone container rather
than its compose stack, which is stopped but unmodified. Rollback is two
commands and is written down.
vh