Two defects, both of the same kind: something the CLI knew and the rest of
the system did not.
A profile can be edited while a replica is running against the old one. The
reconciler deliberately leaves it alone — churning a replica that is serving
costs more than the imperfection — but there was no way to see it, so the
cluster could disagree with its own configuration indefinitely and read as
healthy. Profile now carries a fingerprint, a replica records the one it was
placed with, and both the API and `ctl replicas` say "stale profile" when
they differ. An empty fingerprint is not stale: it means a replica adopted
from an older agent, which is unknown rather than wrong.
Adding a model from the admin page skipped the source check `ctl model add`
has done all along, so a typo or a mirror that is down became a replica
failing on a node minutes later, with an error naming the node. The check
moves out of the CLI into a package both use.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The count is scaling.min, and until now the only way to change it was to edit
server.yaml on the host and restart — or, for a model added at runtime, to
remove it and add it back, which means having its whole definition to hand.
`llmgw ctl scale <model> --min N` instead. Only the scaling block moves:
everything else is read back from what was stored and written out untouched, so
changing a number cannot quietly become a redefinition.
The catalog is rebuilt and validated before anything is written, as in Add. A
max below a min is refused with the stored definition untouched — persisting a
rejected change would come back on the next restart as a catalog that does not
build.
The answer reports the scaling in force rather than the request. The catalog
fills in a max that was left out, and a caller echoing its own request would
print a number the cluster is not using.
A model declared in configuration is refused, for the reason Remove already
refuses one: the YAML is read on every start, so the new count would hold until
the next restart and then silently revert. A cluster disagreeing with its own
config file is worse than an error saying where to edit.
The help says what --max does, because it is not what it looks like: a model
with a minimum runs exactly that many and nothing scales it up under load, and
an on-demand model loads one replica however high its max.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The mirror was a directory and a discipline written down in a README. This
makes the three operations that matter into commands, on the mirror host,
where `llmgw keys` already sets the precedent of operator tooling that works
on files rather than through the API.
The gateway still never writes to the mirror. That property was chosen
deliberately — a mirror writable by the thing reading from it is a way to
replace a model with one every node then fetches without complaint — and a
person running a command does not take it away. `serve` states it rather than
inheriting it, so a handler added later cannot quietly make the mirror
writable.
`add` downloads to a temporary name and renames, for the reason the agent's
fetcher does: a mirror is copied to every node, so a partial file here is a
partial file everywhere. It verifies the length the server promised, reports a
checksum — the mirror is the one place a corrupt file reaches every node
rather than being caught once — and refuses to replace an existing version,
which is the whole point of the layout.
`unused` refuses to answer when it cannot read the catalog. An empty catalog
and an unreachable one produce the same list, everything, and the obvious next
step after that list is deletion. It compares by path rather than by spelling,
because a base typed with a different scheme or a trailing slash would
otherwise report a file in use as unused.
`remove` checks the catalog first and says to retire the entry before deleting
the file, because a node that has to refetch a deleted file cannot, and that
failure arrives later, on the node, looking like something else.
Verified end to end: Range requests answer 206, which is what makes an
interrupted fetch on a node resume; writes answer 405; a traversal attempt
answers 404.
Note: internal/agent/supervisor's TestSidecarRunsBeforeEngine fails under full
suite load on main as well as here — it asserts that one shell's echo lands
before another's, which the supervisor does not promise. Everything else
passes. Left alone rather than fixed in a commit about mirrors.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
llmgw ctl model plan Qwen/Qwen2.5-Coder-32B-Instruct
The arithmetic this replaces is the last thing between having GPUs and
serving a model on them. Choosing tp, gpu_class and a context that will
actually fit means knowing the layer count, the KV head count, what the
weights weigh at a chosen quantisation and how much of a card the runtime
keeps — and getting it wrong is not an error message, it is an
out-of-memory twenty minutes into a load. I computed those by hand for
every model on this cluster.
Both halves are read rather than retyped: the architecture from the model's
own config.json and parameter count, the hardware from the running fleet.
Attention heads in place of KV heads is the classic slip and is worth a
factor of five on a model with grouped-query attention, so it is not a
number anyone should be entering.
Every candidate is listed, not one answer. With cards to spare you want the
full-precision fit; with one card free you want to know a quantised one
exists. Choosing between those is not the planner's job.
The tests are calibrated against files actually downloaded here — llama.cpp
reported 14.62 GiB and 8.37 GiB for the 14B at q8_0 and q4_K_M, and the
model reproduces both — and they caught two errors in my own arithmetic.
The overhead was charged per rank from the whole model's weights rather
than each rank's share, and it reserved a tenth of a card that
usableFraction had already reserved. Between them, Llama-3.3-70B at bf16
across two 80 GB cards came out as not fitting, which is a configuration
people run every day. Slack reserved in two places, each unaware of the
other, reads as caution and behaves as a bug.
Pools are grouped by class and fabric together, because a replica may never
span two fabrics: eight free cards split across two of them are not eight
cards for a model that needs eight, and merging them would plan something
that starts, passes its health checks and hangs on its first all-reduce.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The last piece of not restarting a control plane to try a model:
llmgw ctl model add -f qwen-coder-32b.yaml
llmgw ctl model remove qwen-coder-32b
The file is the same YAML a model takes in server.yaml, read by the same
koanf parser through the same tags, so an entry moves between the two by
being copied and a field that works in one cannot silently mean nothing in
the other.
Wired only when there is a store. A control plane without one says so
rather than accepting a model that vanishes on the next restart, which is
the kind of success that wastes an afternoon. At startup the catalog is
rebuilt from configuration plus what was stored, so models added before a
restart are still there after it — without that the whole feature would be
a slower way to lose work.
Every failure adding a model is the definition being wrong — a collision, a
missing fallback, a profile that cannot be placed — so they are 400s. A 500
would send someone to the server's logs for a mistake in their own file.
The actor comes from the caller and is kept with the row, so a catalog that
has grown over months can say where each entry came from.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
