Commit Graph
13 Commits
Author SHA1 Message Date
Ilker ManapandClaude Opus 5.5 33e678ab84 Show a node's logs on the admin page
Seeing what a node did meant ssh through a jump host, to a machine whose
address nobody remembers, to read a journal only root may open. When an
engine install failed on a new node today, the reason was one line — and it
was four steps away from the page that said the install had failed.

Each node's row on the cluster page now links to its logs: the agent's own,
and every engine running there, chosen from the list the node itself sends.
The page can follow, refreshing every five seconds, and is on both the admin
listener and /admin. `llmgw ctl logs NODE [--source SHARD] [-n N]` reads the
same.

They travel over the stream the agent already holds, so they need nothing
the control plane does not already have: a request goes down, the lines come
back, and a reply that does not come in ten seconds is an agent too old to
answer. The agent keeps its last 2000 lines in memory as well as writing them
wherever it did before; the engines' last few hundred lines were already kept
and sent only when one crashed.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-09-28 12:27:47 +02:00
Ilker ManapandClaude Opus 5.5 7d97c6b74f Install a node's engines on the node, instead of trusting what is there
A node ran whatever llama-server somebody had once unpacked on it. Onboarding
checked an engine only when told its path, installed none, and a node with
nothing on it registered as ready. The one time that went wrong it went wrong
invisibly: the binary was there, executable, and could not start for want of
libgomp1, while the node reported healthy.

The control plane now says which engines every node has, at which version —
`engines:` in server.yaml, defaulting to the llama.cpp build this release was
checked against — and each agent converges on it. What only the node can
know, the node works out: the build for its processor and driver (CUDA with
its runtime when an NVIDIA driver is loaded, CPU otherwise), the OS packages
that build needs from its own package sources, and whether the result runs.
Every archive is checked against the sha256 GitHub publishes for it and
unpacked refusing any path or link that leaves the install directory. ldd
names a missing library outright; running `--version` proves the rest. Only
then is a directory marked installed, and it is checked again every ten
minutes, because an unrelated upgrade can remove a library.

An engine is reported only once installed and seen to run, or when the
agent's configuration names it on purpose — never because something happened
to be on PATH. The agent now says when it has probed, so an empty list means
"has none" rather than "too old to say": a node rebuilt from nothing is no
longer a candidate for every model at the moment it can run none of them.
Placement's refusal carries the node's own words, "installing: downloading
llama-b10991-bin-ubuntu-x64.tar.gz (16 MB)", and so do `ctl nodes` and the
cluster page, along with a warning for a CPU without AVX2 — the VM CPU type
that makes everything five times slower and nothing look wrong.

Agents also report their OS, architecture, vector extensions and NVIDIA
driver. Onboarding installs llmgw itself from the CI release for the node's
architecture, checked against the release's checksums, rather than copying
whatever binary the operator's machine had.

vLLM and SGLang are not installed yet: they are Python environments of
several gigabytes, not an archive, and still have to be named in the agent's
configuration.

Also fixes a race on the weights fingerprint, which two heartbeat loops touch
during a failover.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-09-28 10:59:59 +02:00
Ilker ManapandClaude Opus 5.5 20deb22dfa Let a node describe itself instead of being described by hand
CI / test (push) Successful in 1m47s
Every agent file on the cluster named its own node, its own address, the
path to llama-server and two weight directories — different on every node,
kept true by hand, and not true: node05 carried "ram: 32g" beside a measured
31 GB, looked for weights in an empty directory while fetching them into
another, and the other four never looked in theirs at all, so four nodes
reported no disk. Growing a node's RAM would have gone unnoticed, because
memory was read once, at registration.

The agent now finds these out. Its id is the hostname, which is also the
certificate's common name. Its address is the one on the route to the
control plane, which the kernel picks for a UDP dial without sending
anything. llama-server is looked for on PATH and then where release archives
are unpacked. A missing nvidia-smi is a node without NVIDIA cards rather
than a failed discovery — which also cut discovery short before InfiniBand
on every CPU node not told to skip GPUs. Fetched weights land in
/var/lib/llmgw-weights by default, and wherever they land is always looked
in.

Memory is read on every heartbeat, and installed engines are probed again
each minute and sent when they change, so a VM given more RAM or a node
given vLLM becomes a candidate without anyone restarting its agent. The
control plane logs both changes, since "the node now qualifies" is the
answer to why a model placed an hour after it was asked for.

What is written still wins. The agent file shrinks to the control plane's
addresses and the TLS files, the same on every node; onboarding writes only
the overrides it was given. What cannot be found stays configuration: which
fabric an adapter is on, because OpenSM's default prefix is the same on all
of them.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-09-28 10:13:42 +02:00
Ilker ManapandClaude Opus 5 03e38e7dda Carry the profile fingerprint to the agent and back
CI / test (push) Successful in 1m39s
The stale-profile flag could not fire where it matters. The control plane
keeps no record of a running replica across its own restart — it rebuilds
them from what the agents report — and adoption left the fingerprint empty,
so every replica read as unknown afterwards. That is precisely the moment
the catalog is most likely to have been edited: change the configuration,
restart the server, and nothing would ever say the fleet disagrees with it.

The fingerprint now travels with StartShard, the agent keeps it beside the
pool and fabric it already echoes back, and adoption takes the replica's
version from the agent rather than from the catalog it is about to be
compared against. An agent too old to report it sends nothing, which still
reads as unknown rather than as matching.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-27 23:22:44 +02:00
Ilker ManapandClaude Opus 5 a35e8796d2 Carry a download's progress to where somebody is looking at it
CI / test (push) Successful in 1m28s
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 45e913bd10 Refresh disk and weights while the agent runs, not once when it starts
CI / test (push) Successful in 1m46s
Found by answering "where can we see this live". `ctl weights` was offering a
file for deletion that I had deleted two days earlier, and the node's disk
figure was the one it had when its agent started. Discover() is called at
registration and nowhere else, so both were frozen.

Disk is a fact about a moment, not about a machine. Sampled once, the figure
is wrong on exactly the node worth watching — the one busy filling up — and it
stays wrong until that agent restarts. The heartbeat already refreshes GPU
memory for the same reason, with a comment about noticing a foreign process
"after registration"; disk belonged beside it and I did not put it there.

The stale list cut both ways. A model fetched after registration was invisible
until a restart, so placement could not prefer the node that had just spent ten
minutes downloading it, and the disk check could not see the space it used.

Storage goes in every heartbeat, being a few numbers per filesystem. The file
list goes only when a fingerprint of paths and sizes changes, with a flag
saying the list is meant — without that, an empty list would be ambiguous
between "this node now holds nothing" and "nothing to report", and the second
reading would empty a node's inventory five seconds after it registered.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-20 09:57:25 +02:00
Ilker ManapandClaude Opus 5 774e134ed1 Refuse a node with no room, and take back only what llmgw put there
CI / test (push) Successful in 1m39s
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
CI / test (push) Failing after 1m31s
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 42fd0aa31e Export what the cluster is made of, not only what it is serving
CI / test (push) Successful in 1m28s
The router published twenty-two metric families about requests, endpoints,
admission and scoring — everything about traffic and nothing about the
machines carrying it. There was no way to graph GPU usage, watch a node go
unhealthy, see a fabric fill up, or answer "was the cluster full at the
time", which is the first question anyone asks after an incident. The
agents exported nothing at all.

Exported by the control plane rather than by each agent. It already holds
every number: hardware arrives at registration and state on each heartbeat,
so this is a map read away. One scrape target for a fleet of hundreds, no
Prometheus configuration per node, no firewall rule per machine, and
nothing new running on the nodes. On the same /metrics as the traffic
figures, because correlating "the cluster was full" with "requests were
queueing" should not need two systems.

A collector rather than gauges kept current by a ticker: the numbers are
derived from state that already exists, so computing them when asked is
simpler than maintaining a copy that can drift, and nothing runs between
scrapes.

GPU utilisation is new, and is the number people actually watch. Memory
used says a model is loaded; this says whether it is doing anything, and a
fleet at ninety percent occupancy and two percent utilisation is a fleet
holding models nobody is asking for.

Adding it caught two things. utilization.gpu goes last in the nvidia-smi
query and is optional, because a driver too old to know it returns a
shorter row — requiring it made an llmgw upgrade silently stop discovering
GPUs on an older node, which is far worse than not knowing how busy a card
is. And I gave the new protobuf field number 14, which ecc_errors already
had; buf lint is why that was a moment rather than a corrupted wire format.

Absent is kept distinct from zero throughout, for the same reason as
everywhere else here: an unreported utilisation shown as a flat zero reads
as an idle fleet rather than a missing measurement, and a replica nothing
has reported would be the most idle thing in the cluster.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-17 15:09:27 +02:00
Ilker ManapandClaude Opus 5 c13c567cc5 Know where the weights are, without owning the storage
CI / test (push) Successful in 1m32s
Storage will be different at every installation — Lustre, NFS over RDMA, an
image exported with SRP or NVMe-oF, local NVMe, an rsync — so llmgw observes
it rather than managing it. An agent told which directories to look in
reports what it can see; how the files got there is nobody's business here,
and a node told nothing reports nothing and behaves exactly as every node
did before this existed.

That fact buys two things. Placement prefers a node that already holds the
model over one that must first move tens of gigabytes, as a preference and
never a filter: fetching them is a valid answer, and refusing to place would
turn a slow start into no start at all. And ctl status shows what each
fabric holds.

Per fabric because fabrics are not connected to one another. Weights in
ib-a are not weights in ib-b — the only path between them is the management
network — so a model seeded into one fabric leaves the rest of the cluster
unable to serve it without a slow copy, and nothing said so before now. One
shared filer counts the same as twenty local copies, because "can this
fabric serve it" is the question being asked.

Three distinctions the tests hold to, because each is a way to get this
quietly wrong. A node that was never asked to look must rank with one that
looked and has nothing, or enabling the feature on a single node would
drain every other. An empty directory is not weights, because a
half-finished download looks exactly like one and would send placement to a
node whose engine then fails to load. And local storage is never mistaken
for shared: a filer read as local costs an unnecessary copy, while local
read as shared would have the cluster believe a model is everywhere when it
is on one node.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-17 08:21:16 +02:00
Ilker ManapandClaude Opus 5 3081c6f69b Place on nodes that can actually hold the model
CI / test (push) Successful in 1m23s
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
ilkerandClaude Opus 5 75a8e76706 Survive a control plane restart without orphaning live engines
CI / test (push) Successful in 1m44s
Not persisting replica state left one hole: restarting the control plane made it
forget every replica while the engines kept running. They held GPUs the
inventory believed were free, so the next placement failed to allocate, with an
error naming the new process rather than the old one.

The fix belongs on the agent, not in a database. A row can say "running" about a
process that died; the fleet cannot.

- the supervisor writes the full shard spec, not just a pid and command line. A
  pid identifies a process; the spec is what lets it be described back to the
  control plane and matched to a replica.
- Adopt takes over an engine a previous agent left running. It is not this
  process's child, so it cannot be waited on: it is watched by polling and
  stopped by signalling its group directly. Its earlier output is gone and the
  log says so rather than presenting emptiness as silence.
- every Register reports what the agent is running, not only the first, because
  a reconnect may be a control plane restart and has to recover the same way.
- the reconciler rebuilds replicas from those reports and reclaims their GPUs.
  Anything whose model or profile left the catalog is stopped; nothing will
  route to it and it is holding cards.
- an engine the agent cannot identify is killed. A process holding GPUs that
  nothing can describe is worse than no process, because placement hands those
  GPUs out again.

Stop was also wrong for adopted shards: it checked for an exec.Cmd, which they
do not have, and reported them stopped without killing anything.

TestAgentReconnects had been passing for no reason. httptest's
CloseClientConnections does nothing to an h2c stream — prior-knowledge h2c
hijacks the connection and httptest stops tracking hijacked ones — so the agent
never reconnected, and the assertion on the connection map passed on a stale
entry. Tests now sever connections through their own listener and count opened
streams.

Plan §11 also records what multi-node still needs, since placement landing early
makes it look further along than it is: workers never become Ready because the
agent health-checks every shard while only rank 0 serves HTTP; RayCommand is
written and tested but never called; and startup is fire-and-forget.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 06:15:04 +02:00
ilkerandClaude Opus 5 2373726efd Agent stream: connect the fleet to the control plane
CI / test (push) Failing after 1m29s
One bidirectional connect-go stream per node, carrying registration, heartbeats
and shard status up, and start, stop and drain down. The agent dials out: GPU
nodes sit behind firewalls far more often than a control plane does, and an
outbound connection needs no inbound rule on every node in the fleet.

- registration carries the whole hardware inventory, so there is no separate
  discovery call and a reconnecting agent refreshes what the scheduler knows.
  The fabric labels travel with it; they cannot be inferred from the wire, so
  losing them in transit would silently disable multi-node placement.
- agentsvc is both the stream handler and the reconciler's dispatcher, because
  it holds the open streams and is therefore the only thing that can deliver a
  command to a node.
- the agent validates a profile before launching anything, since an engine that
  refuses a profile does so after minutes of loading, then supervises the
  process and reports every transition with the engine's output tail on failure.
- reconnects forever with jittered backoff. A control plane restart must not
  require touching every GPU node, and a fleet must not reconnect in lockstep
  and knock it over again. Engines keep serving throughout, because the router
  talks to them directly.

llmgw agent is real now, and llmgw server runs a control plane whenever any
model declares a profile. The static endpoint list stays for router-only runs.

Verified with real binaries as separate processes: the agent registers, a
replica is placed, an engine launches through the vLLM adapter's actual argument
construction, streaming traffic is served, and killing the agent moves the node
through unreachable to lost with placement explaining why nothing can run.

config.Model and catalog.Model were the same thing described twice, so the
router now reads catalog entries directly and the validation rules live in one
place.

Still missing: mTLS. The stream is plaintext HTTP/2 and must stay on a trusted
network until that lands.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-16 02:48:21 +02:00