The owner decided (2026-10-07) that we do not connect to anything other teams run on the box, Redis
included. CACHE_URL was emptied on the server and our keys were removed from the shared Redis.
- settings: drop KEY_PREFIX / CACHE_KEY_PREFIX (it only existed because the Redis was shared); comments
say CACHE_URL is intentionally empty and ResilientRedisCache is ready for our own Redis.
- config/cache.py docstring and tests updated accordingly (11 tests, still run against a local redis-server).
- CLAUDE.md: new server rule 8 (touch only our own files and service), status block, historical line
that said "db1 is free" now says not to connect. README, operations, handbook, security doc (item 9
reopened as an open decision) say the same.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Since 2026-10-07 the cache is the shared Redis on the box. Django's RedisCache raises on any network
error and DRF reads the cache for every throttled request, so a Redis outage meant 500 on almost every
route, /admin/login/ and OTP request included (all seven drill tests fail on the stock backend).
config.cache.ResilientRedisCache turns Redis errors into logged (rate-limited ERROR) misses:
get->default, set/delete->ignored, add->True, incr->ValueError. Cache-based caps (DRF throttles, hourly
OTP window, admin-login limiter, payment reconcile lock) are NOT enforced during an outage (fail-open);
DB-backed caps stay. /api/health returns 503 meanwhile. KEY_PREFIX namespaces our keys on the shared
Redis; 1s connect/read timeouts stop a hung Redis from holding requests for gunicorn's 120s.
Tested: 11 tests, incl. a real local redis-server killed mid-test and restarted without restarting the
app. Not tested yet on the server at the time of this commit.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
