The loop healthcheck opened a fresh connection every 60s with schema
auto-apply enabled; the CREATE-IF-NOT-EXISTS lock bursts cancelled
minute_bars autovacuum every single cycle (visible as 'canceling
autovacuum task' each minute post-migration), so the 19M-row table
never got analyzed, snapshot queries crawled, browsers timed out, and
the dashboard log filled with double BrokenPipeError tracebacks.
- healthchecks now set PG_SKIP_SCHEMA=1 (both compose files)
- api/main.py _send_json swallows BrokenPipe/ConnectionReset (client
hung up; nothing to tell it)
- live DB: ALTER SYSTEM max_wal_size=4GB, shared_buffers=1GB,
effective_cache_size=3GB, checkpoint_completion_target=0.9 (the
checkpoint-every-24s warning under migration load on NAS storage)
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
