bvandeusenandClaude Opus 5 828c6a5ae3 fix: each lane needs its own celery node name, or three of four vanish (4295) ...

Found by the all-role smoke on its very first execution (run 7319), which is
the whole argument for having added it one commit ago.

Celery's default node name is `celery@<hostname>`. In the single-container
layout all four lanes share one hostname, so all four registered as the SAME
node. Celery says so itself:

    DuplicateNodenameWarning: Received multiple replies from node name:
    celery@72adc5b706a7

`inspect` collapses four replies into one dict key and the last one wins, so
three lanes read as absent — and WHICH three varies between calls:

    lanes not answering: maintenance_long, ml, worker
    lanes not answering: maintenance_long, scheduler, worker

Fatal twice over:

  * The composite healthcheck can never pass. In Swarm that is a container
    that never goes healthy — restart loop, then an automatic rollback of a
    deploy whose image was fine.
  * `pool_grow`/`pool_shrink` take a `destination` of node names. The UI dial
    and the autoscaler would have resized whichever lane happened to answer
    rather than the one asked for — silently, and differently each time.

Every celery role now starts with `-n "${CELERY_NODENAME:-celery}@%h"`, and
the generated supervisord config sets that per lane. The lanes become
worker@<cid>, scheduler@<cid>, maintenance_long@<cid>, ml@<cid> — distinct,
so inspect keeps four entries and `destination` addresses what it names.
`inspect_lanes_sync` maps hostname to lane by QUEUES, so nothing there
changes; it just stops having three of its four entries overwritten.

Unset, it falls back to `celery` — exactly celery's own default — so every
service in the multi-service stack is byte-identical to before, including the
`celery@$HOSTNAME` healthcheck in docker-compose.yml and in the operator's
Swarm stack.

The test asserts DISTINCTNESS across the whole lane table rather than a fixed
string per lane. The property that broke is that no two collide, and stating
it that way keeps holding when a lane is added.

This is the bug I said a live deploy was needed to find, found in CI instead
for the price of one `docker run` — and it would have met the operator as a
rollback loop on their first consolidated deploy.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR

2026-09-23 08:52:56 -04:00

..

app

fix: each lane needs its own celery node name, or three of four vanish (4295)

2026-09-23 08:52:56 -04:00

__init__.py

feat: scaffold backend Python project (Quart + SQLAlchemy + Celery deps)

2026-05-14 07:31:39 -04:00