Commit Graph
17 Commits
Author SHA1 Message Date
Ilker ManapandClaude Opus 5 2acd794022 Stop placing engines on nodes that do not have them
A node's registry holds an adapter for every engine whether or not its binary
exists, the agent never said which were installed, and placement carried an
Engine field it had never once read. So a vLLM replica was as happily placed on
a node with no vLLM: the node registered healthy, the shard failed minutes
later with "executable file not found" in the engine's own words, and the
reconciler tried again.

That is how fifteen gigabytes of safetensors reached this cluster's mirror
before anybody noticed it had no card and no vLLM to run them with.

Agents now probe what is installed and report it — the protocol has carried
engine_versions since it was written and nothing ever filled it in. Placement
filters on the key set, `ctl nodes` has a column, and the mirror page's serve
warning is a fact instead of a guess about cards, which would have waved
through a fleet of eight-GPU nodes that never had vLLM.

Probing resolves binaries and runs none of them. The first version asked each
engine for --version, which is fine for an engine and not fine for the wrapper
scripts people put in front of one: a script that shifts past flags it does not
recognise and then execs the server will start an inference server, at agent
startup, on every node. The agent's own test suite installs exactly such a
script and caught it. So presence is a path lookup, and the version is left to
`ctl engine-check`, which is run by somebody who meant to run the engine.

SGLang is the exception and has to execute, because a module has no path to
look up — but the command is llmgw's own one-line import rather than the
engine's launcher. Its exit code is the answer: python3 is on almost every
machine, and treating a failed import as "installed" reported SGLang on every
node in a fleet that had none, which is the failure being fixed, inverted.

Probed once, not per reconnect, and bounded by the context that registration
waits on: an agent that cannot reach the control plane is worse than one
reporting an incomplete list.

A node that reports no engines at all is not excluded anywhere — by placement,
or by the page. That is what every agent older than this reports, and emptying
a fleet on a control plane upgrade is a worse failure than the one being fixed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-27 16:11:55 +02:00
Ilker ManapandClaude Opus 5 a83493bddb Show what a group spent, and fix the reports that never ran on PostgreSQL
Quotas can be written on an organization, a team or a project, and nothing
could show what any of them had used: usage came back per key, per user and per
model only. A quota whose consumption cannot be seen is one nobody reviews
until the day it refuses somebody — and since the previous commit made a group
quota a shared pool, it is now a number several people are spending against
without being able to look at it.

`llmgw ctl usage --by team` sums every key beneath each group, with the budget
that level sets beside it.

Beside it, and only when that level sets one. A team bounded by its
organization's budget has none of its own, and printing the organization's
against each of its teams would read as though each had that much — the exact
misreading this work exists to remove.

Joined through api_keys rather than read from usage.project_id: that column
records where the key was when the request was served, while the quota is
written against the tree. They agree until a key is moved, and a report that
disagrees with the limit shown beside it is the useless one.

Three existing reports were fixed on the way, all failing on PostgreSQL and all
passing in tests, because the tests run on SQLite:

  column "k.name" must appear in the GROUP BY clause    (UsageSince)
  column "us.email" must appear in the GROUP BY clause  (UsageByUser)
  column "usage.ts" must appear in the GROUP BY clause  (UsageBuckets)

SQLite picks an arbitrary row for an ungrouped column and carries on; PostgreSQL
refuses. The first two were selecting names they had not grouped. The third
grouped "ts / ?" while selecting "(ts / ?) * ?", which PostgreSQL matches as
text and so saw a bare ts — it is grouped by ordinal now, the same expression by
construction. The dashboard's usage charts have been empty on the cluster this
whole time, with the reason only in the log.

All four queries were run against the cluster's own PostgreSQL before this was
committed, because passing on SQLite is what they were already doing.

The grouping level picks from a fixed table of levels rather than being
interpolated, so an unknown one is an error and not a fragment of SQL.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-27 12:26:14 +02:00
Ilker ManapandClaude Opus 5 3aa250428a Keep what a benchmark found out, instead of leaving it in a terminal
`ctl bench` has always been able to work out what one replica can serve — it
ramps concurrency until the SLO breaks and reports the last level that held.
It printed that and nothing kept it, so the one number saying what a replica is
worth lived in whoever ran it's scrollback. Everything downstream then had to
guess: admission applies a single global default for healthy queue depth, and
sizing a model against real demand had nothing to size against.

`ctl bench --save` records it; `ctl capacity` reads it back.

Keyed by model and profile. Capacity belongs to the hardware and the engine
arguments as much as to the weights, so the same model on CPU and on an H100
are two numbers, and one key would overwrite the other on every run.

The profile is looked up from the replica rather than asked for, because the
control plane already knows which profile answers on which endpoint and a
measurement filed under the wrong one is worse than none. A target that is not
a replica — the gateway, usually — is refused with that said: benchmarking the
whole path is worth doing and says nothing about the hardware.

The conclusion is stored, not the ramp. Every level and its latencies are worth
reading once while judging whether the run was sound; keeping them would grow
without bound as a model is re-benchmarked.

Re-measuring replaces. A second run is a better answer to the same question,
not another data point, and keeping both would leave a reader choosing between
numbers with no basis for the choice.

The SLO and the date are stored with it. Capacity means nothing without the
target it was measured against, and hardware and engine builds change — a
measurement is an observation with a date on it, not a fact about the model.

A failed save is reported and not fatal: the run has already cost the GPU time.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-27 11:51:58 +02:00
Ilker ManapandClaude Opus 5 707d774c76 Change a model's replica count without editing a file on the control plane
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>
2026-09-27 11:25:05 +02:00
Ilker ManapandClaude Opus 5 a35e8796d2 Carry a download's progress to where somebody is looking at it
The agent has always logged a percentage as it fetches weights, with a comment
saying a replica pulling a hundred gigabytes and one that is wedged look
identical from the control plane. They still did: the log is on the node, and
the node is not where anyone is looking when a replica has been starting for
ten minutes.

Progress now rides on the shard status and appears under the replica in `ctl
replicas` — a line rather than a column, because most replicas are not
downloading anything and a column would be empty for all of them.

It is deliberately not a state transition. Treating each chunk as one would
re-mark the shard as starting on every report and reset the timer that decides
when a slow start has become a failed one, so an hour-long download would keep
a doomed replica alive indefinitely. It arrives on its own method for that
reason, and a real transition clears it — otherwise a finished download sits in
the listing at ninety-nine percent under a shard that has been serving for an
hour.

Watchers are keyed by source rather than by shard, because a fetch is
single-flight: eight shards starting together produce one download and all
eight are waiting on it.

No percentage is invented when the server sent no length. One that stops moving
is worse than a byte count that keeps rising, so the field is absent and the
listing says "so far".

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-27 07:49:08 +02:00
Ilker ManapandClaude Opus 5 8e57171c4f Let ctl ask a question instead of printing the whole fleet
Five nodes fit in a table. Fifty do not, and this is built for people who
already have racks of GPUs — so the flags are how a question gets asked:
which nodes on this fabric, which of this GPU class, which are not ready,
which replicas have a shard on this machine.

Filtered here rather than in the API, so --json is narrowed the same way the
table is. A server-side filter would be two implementations of one predicate,
and the JSON one is the one nobody would notice had drifted.

An empty result says which case it is. A filter that matched nothing and an
empty fleet call for opposite next steps — one is a cluster to look at, the
other is a word to correct — and printing "no nodes" for both makes a mistyped
fabric name read as an outage.

A state matches on prefix because states are few and distinct and somebody
scanning a fleet types quickly. A pool matches either half, because it is
fabric/class and both are worth narrowing by. A replica is found from any of
its nodes, since one spanning two machines is on both.

--label takes a bare key as "carries this at all", which is how you ask for
every node with a role without caring which. The flag's help said so before
the parser did; the test caught them disagreeing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-27 07:30:51 +02:00
Ilker ManapandClaude Opus 5 774e134ed1 Refuse a node with no room, and take back only what llmgw put there
Two halves of the same problem: nothing stopped a model being placed on a node
that could not hold it, and nothing ever removed the weights of a model that
had been deleted from the catalog.

Placement now has a disk check, shaped exactly like the memory one it sits
beside, with one addition: it is skipped on a node that already holds the
weights. A node holding the file needs no room for it, and without that the
node best placed to run a model — because it already has it — is the one most
likely to be rejected, since holding the file is what used the space.

Reclaiming is the dangerous half, so the whole design is about what it will
not do. llmgw deletes only files it fetched itself, and that is a calculation
rather than a heuristic: the cache name is a hash of the source, so the set of
wanted files can be computed from the catalog exactly. Anything without that
name was put there by an operator — scp, a shared mount, a copy by hand — and
is none of this system's business however unreferenced it looks. A model that
took a week to copy must not be removable by a command someone ran to tidy up.

The node checks every path again before unlinking it, and that duplication is
the point. The control plane knows the catalog; the node knows its disk. A
control plane that is wrong, newer than the agent, or tampered with must not be
able to talk a node into deleting something, so the agent refuses anything
outside its own cache directory or without the cache name — including a path
that tries to traverse out of it.

Listing is the default and deleting takes --collect. The summary says "asked to
remove", because each node decides, and one that refuses a path it cannot prove
it fetched is this working rather than failing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-18 09:51:05 +02:00
Ilker ManapandClaude Opus 5 753f4e3265 Let a node say how much room it has left
Disk was the one resource nothing reported. `statfs` was already being called
on every model directory, but only to ask whether the filesystem was a network
one — the free space it returns in the same struct was thrown away. So the
only way to find out why a node was filling up was to ssh to it, which is what
this system exists to avoid.

Reported per filesystem rather than per configured directory. Free space
belongs to the disk, not the path: two model directories on one disk are one
pool of bytes, and counting them separately would let the control plane add
24 GB to 24 GB and place a 40 GB model on a node that has 24.

Shared filesystems are summed separately from local ones and left out of a
node's own total. Space on a filer belongs to everyone mounting it, so twenty
nodes would otherwise each report the same free terabyte, and a scheduler
would place twenty models into room for one.

Nothing reported means nothing is known, everywhere: an agent too old to send
storage and a node with no model directories both send nothing, and both must
read as unknown rather than as a full disk. `ctl nodes` and the dashboard show
a dash, the metric is absent rather than zero, and a missing directory — which
is what an unmounted filer looks like — is skipped rather than reported as
having no space.

Shown as free out of total, because the first is useless without the second:
8 GB free is comfortable on a 10 TB filer and nearly full on a 10 GB root
partition, and only the second stops a model being placed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-18 09:38:57 +02:00
Ilker ManapandClaude Opus 5 d07dddb1bb Say plainly whether a model is serving, and why not
Reported after watching a model appear in ctl models before it could answer
anything. Checked: clients are not told early — /v1/models listed it only
once a replica was ready, and the chat picker reads the same source. The
operator view showing it is deliberate, because a model coming up is
exactly what someone running the cluster wants to see.

But the report pointed at something real. That view distinguished "a
replica is coming up" from "nothing could be placed" by a parenthetical —
"0/1 ready (1 total)" against "0/1 ready" — and those need opposite
responses: one means wait, the other means look at explain-placement. On
four models the difference is findable. On forty it is invisible, and a
model that will never start reads exactly like one that is thirty seconds
away.

SERVING now answers the question that was being asked of the replica counts
— can a client use this right now — and STATUS says which of ready,
starting, not placed or stopped is the case.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-17 06:34:04 +02:00
Ilker ManapandClaude Opus 5 331de9b495 Add and remove models from the command line
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>
2026-09-17 06:27:53 +02:00
Ilker ManapandClaude Opus 5 9d8cd5e284 Track which replicas are actually being used, and summarise the fleet
Two things a cluster with many nodes and many GPUs needs that were missing,
and they are the same thing seen from two distances.

Idle tracking. The control plane knew what was placed and whether it was
healthy, never whether anyone wanted it — so on a fleet with more models
than cards there was no way to answer the first question anyone asks, which
is what can I stop. The router is the only thing that knows, so it now
reports it: a timestamp written in Acquire, where a request already meets an
endpoint under a lock already held, and collected once a tick as a map. That
shape is the point. Per-request notification would be a firehose carrying
one bit — the newest timestamp wins — and this costs the same on four
replicas as on four hundred.

It travels through an interface in the direction opposite EndpointSink, for
the same reason that one exists: the control plane decides what should run,
the router knows whether anyone wants it, and neither should need to be in
the other's process to say so.

Unknown is kept distinct from idle throughout. A router that has just
restarted knows nothing, and a zero timestamp would be the oldest idle
replica in every comparison — so one restart would nominate an entire fleet
for eviction. Absent from the map, "-" in the table, negative in the JSON,
and IdleFor returns a second value rather than a duration anything could
act on by mistake.

ctl status. A per-node listing is right for four nodes and wrong for two
hundred: how full am I, what is broken, what is holding cards nobody is
using are aggregates, and reading them off a long table is a chore, which
means it gets skipped. Capacity per GPU class with usage bars, free whole
nodes per fabric — the number that decides whether a multi-node replica can
land, since free cards on the wrong fabric are not capacity for a model that
spans nodes — replica and model counts, models that cannot be placed, and
what has gone unasked-for. Derived from the same state the tables show, so
it cannot disagree with them.

Unhealthy GPUs count as neither used nor free, because counting them free is
how a cluster looks like it has room it does not.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-17 00:52:34 +02:00
Ilker ManapandClaude Opus 5 84896c0ad2 Add ctl tool-check, so an afternoon becomes one command
The catalog now declares whether a model supports tools, which makes it a
claim. This is the claim that can be checked, and the one worth checking:
the gateway forwards a tools array to any model, and an engine that does
not return structured tool_calls looks exactly like a model that ignores
its tools. Every OpenAI-compatible client then behaves as though the model
is broken.

It separates the two diagnoses, which have the same symptom and different
fixes. The model ignoring its tools is fixed by choosing another model. The
model making the call and the engine handing it back as prose is fixed by
changing engine build, and no larger model will help — which is what
today's investigation established only after eliminating the gateway, the
model size, two chat templates and tool_choice in turn.

Against the live engine it says:

  the model called the tool and the engine did not parse it.
    {"name": "get_weather", "arguments": {"city": "Istanbul"}}
  This is the engine, not the model.

engine-check asks whether an engine still accepts our flags; this asks
whether it behaves. Flags were the failure we had seen, so they were the
failure we checked for. Non-zero exit, so a rollout can be gated on it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 23:30:02 +02:00
Ilker ManapandClaude Opus 5 3081c6f69b Place on nodes that can actually hold the model
Placement had no idea how much memory a node has or a model needs. A CPU
profile has no card to be free, so eligibleNodes accepted every ready node:
Qwen2.5-Coder 14B, whose working set is about 24 GB, would have been placed
just as happily on one of the 8 GB nodes, which reports itself perfectly
healthy right up until the OOM killer arrives.

node_selector was yesterday's stopgap and it is the operator restating by
hand something the system can know. Agents now report MemTotal, profiles
declare min_memory_gb, and placement filters on it, naming what was short —
"has 8 GB of memory, needs 24" is actionable where "no candidates were
considered" is not. The label selector stays, because "this node is for
coding models" is a real thing to want to say that memory does not express.

Two deliberate non-exclusions. A profile with no requirement fits anywhere,
which is every profile that exists today. And a node that reports no memory
is still usable: an agent older than the field says nothing, and letting a
control plane upgrade quietly empty half a fleet is a worse failure than the
one this prevents.

ctl nodes grows a MEM column showing "-" rather than 0 for a node that did
not say, because an old agent is not a small machine.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 23:12:44 +02:00
Ilker ManapandClaude Opus 5 5b425c32e5 Ship binaries with releases, and ask engines whether our flags still exist
A release was a git tag. Installing llmgw on a node meant having a Go
toolchain, and the onboarding script copied a binary from wherever it was run —
which works and quietly makes whoever runs it the build server, with the fleet
ending up on whatever was in their working tree. Tags now build static
linux/amd64, linux/arm64 and darwin binaries and attach them. CGO_ENABLED=0 is
the point: it has to run on a node whose libc is older than the builder's, and
llmgw has no C dependency because modernc.org/sqlite is pure Go precisely so
this stays true. Verified: "not a dynamic executable", runs on a node, reports
its version.

`ctl engine-check` closes the other half of the phase 4 gap. llmgw's launch
arguments are read from each engine's documentation, and engines rename flags
between versions; when that happens the failure arrives minutes into a model
load, in the engine's own error message, on a node nobody was watching. It
builds the widest command llmgw would ever produce — multi-node, since a flag
that only appears there is the one nobody notices has gone — and checks each
flag against the engine's own --help. No GPU: a CLI prints its help anywhere.
Verified against llama.cpp b10991, all seven flags accepted.

Flags are matched on a word boundary, so --port is not satisfied by
--port-range. Without that, a renamed flag would sail through the check that
exists to catch renamed flags.

It also warns when the help text looks truncated, which is how the first run
went: llama.cpp's help cut to 400 of its 725 lines reported five flags as
missing that the running cluster uses.

TestSidecarRunsBeforeEngine was flaky under a full run, and worse than flaky —
its wait loop fell through on timeout, so a slow machine turned the ordering
assertion into a no-op and the failure surfaced later as something else. It now
asserts, with a deadline that suits a machine running every other package at
the same time.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 16:44:29 +02:00
Ilker ManapandClaude Opus 5 05bdc7d6d4 Add ctl bench, and fix two holes it walked into
`ctl bench` measures what a replica can actually serve, so weight,
target_waiting and kv_ceiling stop being numbers somebody typed. Concurrency
climbs until the SLO breaks and the last level that met it is the capacity:
peak throughput arrives long after latency has become unusable, so throughput
alone overstates what the hardware can serve. Queue depth and KV usage are
read from the engine while it is still meeting the target, which is exactly
what admission should treat as healthy.

Prompts are unique per request by default. With one repeated prompt the
engine's cache answers most of the prefill and the measurement describes the
cache rather than the hardware; --shared-prefix asks that question
deliberately, and it now produces byte-identical prompts, which the first
version did not — it dropped the random header and still picked words at
random, so the cache missed and the flag quietly measured the thing it exists
to avoid.

Running it against the cluster turned up two real defects:

A replica stuck in Starting never timed out. Every other way out of that state
needs the agent to report something, and when it never does the replica sits
there holding GPUs and counting towards the model's replica count while
serving nothing. Two of them had been like that for eight minutes past a
two-minute startup timeout, and nothing would ever have moved them.

They were stuck because adoption lost to a replica we had only placed. Replica
ids come from the model name and a counter, so a control plane that restarts
and places before its agents reconnect builds a different replica under the
same id on a freshly allocated port; the agent's report of the engine that was
actually serving was then discarded as already-known. The cluster pointed at
port 20004 while the engine answered on 20000. The fleet is authoritative
about what is running, so what we merely placed now loses to what an agent
reports — unless our copy has a shard that has actually come up, in which case
two things really are running and the stray is the one we did not ask for.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 09:51:37 +02:00
Ilker ManapandClaude Opus 5 1e3cafdc86 Add a private CA and mutual TLS for the agent stream
A node's identity was whatever the agent said it was. With mutual TLS the
control plane compares the client certificate's common name against the
claimed node id and refuses the connection when they disagree, so identity
becomes something a node proves rather than something it picks.

A public authority cannot supply these certificates: Let's Encrypt and its
peers stopped issuing the clientAuth usage, and Go verifies client chains
against it. Hence internal/tlsconf/ca.go, a small authority whose key lives
on one machine and whose root is trusted everywhere, and `llmgw ctl cert`
over it so issuing is reproducible instead of remembered openssl.

The server certificate's hosts matter more than they look: hostname
verification reads subject alternative names and ignores the common name
entirely, so a certificate without the address agents dial — bare IP
included — is rejected no matter what its subject says. There is a test for
exactly that, because it is the failure everyone hits once.

requireIdentity stays wired to false until the configuration lands, so this
commit changes no running behaviour.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 07:28:56 +02:00
ilkerandClaude Opus 5 e1eb1d4149 Phase 3: ctl, and make draining a rolling move
ctl talks to a management API on the admin listener, not the client-facing one.
The two have different audiences: one serves inference to whoever holds an API
key, the other lets a caller cordon nodes and read the cluster's shape.

- nodes surfaces unhealthy GPUs and why they are excluded. That is usually the
  answer when a node looks idle but nothing will schedule onto it, and it was
  invisible before.
- explain-placement prints every candidate considered and why it was rejected.
- replicas shows the shards a replica is made of, with per-shard errors.
- cordon, uncordon and drain are one endpoint with different targets, because
  the difference between cordon and drain is exactly what an operator needs to
  be sure of before running either.

Draining had to be fixed first to make ctl drain worth having. A drained replica
was stopped on the next pass, which cuts in-flight requests — the thing draining
exists to avoid. Now a node marked Draining has its replicas drained, the model
falls below its desired count, a replacement is placed elsewhere, and the
original is stopped only once the replacement is serving. A grace period bounds
it, because draining the only node that can host a model would otherwise never
finish and the node could never be taken out of service.

Verified against a two-node cluster of real binaries: draining moved a replica
to the surviving node and traffic kept returning 200 throughout.

ctl logs is deliberately absent. It needs a request/response pair the agent
protocol does not have, and the failure path already ships an engine log tail
with every status report — so the case that matters most is covered, and
reading a healthy shard's output on demand is not worth a protocol change yet.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 06:27:21 +02:00