Both playlists shared one hash and sorted set, causing two independent
failures.
Starvation: Snapshot performed an unbounded ZRANGEBYSCORE and HMGET,
decoded the whole queue, and the matcher then truncated to its candidate
limit *before* filtering by playlist. A large casual prefix could
therefore leave the ranked worker with zero candidates indefinitely even
while ranked tickets were queued further down the set.
Mutual erasure: each matcher captured only its own playlist as the
durable source, but Rebuild replaced the shared keys, so a casual repair
wiped ranked projections and vice versa.
Namespace the keys per playlist, push the limit into Redis (LIMIT 0 N)
so reads no longer scale with total queue depth, and scope Rebuild to
one namespace. Rebuild now rejects a candidate whose playlist does not
match the namespace, which would reintroduce the starvation. Upsert
derives the namespace from the candidate; Remove takes the playlist,
since a ticket ID alone no longer identifies its namespace.
Add tests for a 300-deep casual backlog not starving ranked, for neither
playlist's rebuild erasing the other, and for the limit being applied
without losing enqueue ordering.
Every existing RedisCandidateIndex test runs against miniredis -- a
from-scratch Go reimplementation of the Redis command set, not real
Redis's own float64 score encoding, TTL/expiry, or RESP behavior.
Add an opt-in integration suite (mirroring postgres_integration_test.go's
pattern: //go:build integration, COSMIC_CLASH_REDIS_ADDR-gated) plus
scripts/run_redis_integration.sh against a disposable redis:7-alpine
container, covering:
- upsert/snapshot/remove against a real server
- a real TTL actually waited out (not miniredis's manual
FastForward), proving expiry really happens on the wire
- the documented 'Redis restart or lost keyspace' repair path
exercised against an actual FLUSHALL, not a simulated empty map,
including that the repair actually persists back to Redis (a
second snapshot reads it without a second durable-source call)
Verified stable across 3 runs with -race against a real container.
Josh Creek