unkinben
6dc72920da
Lazy per-replica scans re-derived RPM metadata on the client request path and, run independently on every replica, multiplied GitHub queries by the replica count. A single background syncer with a shared rate limit, ETag conditional checks, and a DB lease keeps metadata fresh off the request path while bounding GitHub load to ~once per mutable_ttl across the fleet. - Add a single per-process syncer (started at boot, stopped on shutdown) that owns a deduped/coalescing work queue, a worker pool, and one global token-bucket rate limiter bound onto the github provider so every GitHub call (releases list + each ranged asset GET) acquires a token first. - Check each github_rpm remote for new/changed releases on its mutable_ttl cadence; derive only new/changed assets incrementally and prune assets that disappear upstream, so repodata is served from primed DB rows. - Prime metadata in the background on remote creation; the create call never blocks on a derive. - Send the stored releases-list ETag as If-None-Match; a 304 derives nothing (and does not count against GitHub's rate limit), making an unchanged repo nearly free. - Coordinate replicas through a github_rpm_sync_state row (last_synced_at, etag, sync_lease_owner, sync_lease_expires): a periodic scan runs only for the replica that atomically claims the lease, bounding total GitHub load to ~once per mutable_ttl regardless of replica count. - Keep the request path fast: serve current cache, enqueue a prime on an empty cache, and return a bounded wait then a retryable 503 rather than blocking on a cold derive. - Add GITHUB_SYNC_RATE/BURST/WORKERS/POLL_INTERVAL config (conservative defaults) and document the syncer in the README.