bvandeusen 7309d1d6d4 fix(alembic): serialize concurrent migrators with an advisory lock ...

Every web replica runs 'alembic upgrade head' in its entrypoint, so under
docker stack deploy two replicas can boot at once and race the same DDL —
0040 raced in prod (operator-flagged 2026-06-07): one backend wedged on the
series_page lock while a second tried to re-CREATE series_chapter, and the
loser died with AdminShutdown, crash-looping the web service.

Wrap run_migrations() in a transaction-scoped pg_advisory_xact_lock acquired
BEFORE the version table is read. The first replica to reach it migrates and
holds the lock for the whole upgrade; siblings block, then find the version
already at head and apply nothing. Works regardless of replica count and
needs no Swarm depends_on ordering (which stack deploy ignores anyway).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

2026-06-07 19:59:45 -04:00

..

versions

feat(series): assisted-continuation matcher + suggestion queue — backend (FC-6.3)

2026-06-07 18:58:18 -04:00

env.py

fix(alembic): serialize concurrent migrators with an advisory lock

2026-06-07 19:59:45 -04:00

script.py.mako

feat: add SQLAlchemy declarative base, Alembic environment, and gitignore fix

2026-05-14 07:32:58 -04:00