An external model with api: comfyui is a ComfyUI server. A request for
pictures goes through the same key, allowlist, limit, admission and guard
checks as any other; at the replica it becomes a workflow — a built-in
(flux-schnell, flux-dev) or a JSON file in API format, with {{prompt}},
{{width}}, {{seed}} and the like filled in — queued, waited on, and its
pictures sent back as b64_json. A client that leaves takes its workflow
off the queue or interrupts it. ComfyUI is never scraped for metrics.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The router read SGLang replicas with vLLM's names, and SGLang was started
without --enable-metrics, so it served no /metrics: every scrape failed as
if unreachable and the replica was routed to blind. It now gets
--enable-metrics and a mapping of its own (sglang:num_running_reqs,
num_queue_reqs, token_usage, the token counters and num_requests_total, as
0.5.21 publishes them). engine-check asks python -m sglang.launch_server
--help instead of Python's own help, and SGLang is given --tp-size rather
than the --tp argparse only takes as an abbreviation.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Engine trtllm runs trtllm-serve on one node, through a launcher of
llmgw's that demands the replica's key and turns on the Prometheus
endpoint its queue and cache gauges are read from; the router reads it
at /prometheus/metrics. Brought by the operator (engines.trtllm.python),
not installed; checked by ctl engine-check trtllm. Written against the
documented CLI, server and metrics and tested with stand-ins: not yet
run on a datacenter GPU.
mirror import-ollama copies a model's GGUF, and a vision model's
projector, from Ollama's directory into the mirror, checked against the
digest Ollama named each blob by; mirror import does the same for any
local file. The console's Mirror view imports from Ollama with I.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
A catalog model with external {url, model, api_key_file} and no profiles
is published as an endpoint by the control plane, the key read from its
file each time; the router rewrites the request's model to the provider's
name and sends its key. It is never scraped nor stale, and nothing is
placed for it. Named in fallbacks, it serves when the cluster has no room.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
CI's test job has failed intermittently — two of three runs on some days —
while every run here passed, including six repetitions on one CPU under the
race detector with eight packages at once. The difference is a shared,
loaded Linux runner, and the tests most exposed to it are the ones that
sleep a fixed time and then assert:
- admission: idle admission bounded at 50ms of wall clock against a 1ms
tick, and a queued request checked for after a 50ms sleep;
- scrape: a 10ms scrape timeout, which on a slow runner reports the engine
unreachable and then the violation a second time, in a test that counts
one;
- supervisor: log lines, three lines of output and a removed state file
each checked after a fixed sleep, and an exited worker bounded at 1.5s;
- agent: a heartbeat checked for after four intervals.
Each now waits for its condition up to a deadline of seconds, and the two
wall-clock bounds are set against what they exist to distinguish — the
admission queue's tick raised to ten seconds, the exited worker bounded
below the five-second grace it must not wait out — rather than against how
fast this laptop is.
Without the CI logs this cannot be proven to be the failure; these are the
tests that fail when the machine is slow, and they no longer do.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Engines listen on every address their node has, with no key. Checked on the
live cluster: from a neighbouring node, a request straight to an engine's
port was answered — past the gateway's authentication, quotas and
accounting, by anyone who could reach the node.
Each replica's engine is now started with a key and refuses requests without
it. The key is derived from the replica id with an HMAC over a secret kept
in the store, rather than stored per replica: the router has to send the
right key to replicas this process never started — adopted after a restart,
or placed by the other control plane — and a function of a shared secret
gives that without a table to keep in step. A key taken from one node opens
that replica only. The secret is made on first use and copied with the rest
of the store when moving to PostgreSQL; a new one would lock the router out
of every running engine at the moment of the move.
The key reaches llama.cpp and vLLM through their environment
(LLAMA_API_KEY, VLLM_API_KEY) rather than their command line, which every
user on the node can read; SGLang only takes it as an argument. The agent's
readiness check, the router's proxy and its metrics scrape send it, the
client's own Authorization still never reaches the engine, and `ctl bench`
fetches the key of the replica it is pointed at from the admin API.
Engines started before this keep running without a key until their replica
is next started. With no store there is nowhere to keep the secret, and
engines start without one, with a warning.
Also formats two files that went in unformatted.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Deployed against real llama.cpp, every scrape failed. The mapping named
llamacpp:kv_cache_usage_ratio; build b10991 serves fifteen metric families
and none is a cache ratio. Because KV usage was mandatory, that one absent
name threw away the two metrics the engine does publish, and the router
scheduled to all three replicas blind while the cluster looked healthy.
A mapping that leaves a metric unnamed now means the engine does not publish
it, and the field stays zero. Naming one the engine does not serve is still a
violation, so this does not become a way to tolerate a typo. Running and
waiting can never be omitted: an engine that reports neither what it is doing
nor what is queued cannot be scheduled against at all. For llama.cpp this
costs the KV half of the saturation signal, which is a real loss softened by
its fixed slot count — queue depth already says when it is full.
The second half is why it took a deployment to notice. A contract violation
was logged per scrape at debug level, so at the default level nothing said
anything. It is now a warning, once, with a matching line when it clears.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
llama.cpp is what makes a cluster with no cards useful: it serves the same
OpenAI API on CPU, so the whole path — placement, supervision, scraping,
scheduling, admission — can be exercised end to end on ordinary machines.
Three things had to give way for it.
A profile may now omit its GPU class, and that is how it says it runs on the
CPU. Only engines that can actually serve without a card may omit it; for
vLLM an omitted class stays an error, because otherwise a typo becomes a
replica placed on a machine with no hardware and diagnosed minutes later
during model loading. Placement spreads CPU replicas instead of bin packing
them, since unlike GPUs there is no allocation to stop two of them sharing a
machine's cores.
Metric mappings are now per engine rather than per cluster. llama.cpp calls
the same three numbers requests_processing, requests_deferred and
kv_cache_usage_ratio, and a single global mapping would leave half a mixed
fleet unmeasurable. An empty mapping still defaults to vLLM's names; one that
names its own Running metric is taken as a complete statement, so the fields
it leaves blank stay blank rather than being filled with names that engine
cannot have.
The adapter refuses multi-node and tensor-parallel profiles. llama.cpp splits
across local GPUs by a different mechanism than this adapter drives, and
accepting either would produce a replica that starts and then serves from one
machine while the catalog believes it has several.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The code behind plan §7.3-7.6:
- breaker: folds cooldown and circuit breaking into one component
(FailureThreshold=1 gives LiteLLM-style cooldown), with exponential backoff
and half-open probes.
- endpoint: live state registry. Inflight counting, staleness detection, drain
rate derived from counters. A scrape failure does not trip the breaker — the
engine may be serving fine while only its metrics endpoint is down.
- scrape: parses the §7.6 metric contract. Errors when any of the mandatory
three is missing; the metric name mapping is overridable, since names drift
between versions (plan §14).
- scheduler: the filter -> score -> pick pipeline. A "strategy" is now just a
set of scorer weights; chat, batch and long-context are the same code with
different weights. Scorers: queue, kv (hard penalty above the ceiling),
inflight, load, weight, session (bounded-load consistent hashing). Pickers:
max-score, p2c, softmax, round-robin.
Decision carries the rationale — which scorer produced what, which filter
dropped how many. Tuning the weights without that is guesswork.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
ilkerandClaude Opus 5