Cache
The snapshot lives in Django's cache, alias GLOBAL_CONFIG_CACHE_ALIAS (default default).
| Key | Meaning | TTL |
|---|---|---|
global-config:{key} | one typed DTO | none |
global-config:snapshot-ready | full snapshot marker | none |
global-config:refresh-lock | refresh lock | 30 seconds |
Lock wait timeout is 35 seconds. If the wait times out, the service accepts an already published snapshot or raises GlobalConfigRefreshLockTimeoutError. It never publishes without owning the lock.
Publish uses cache.set_many. On Redis/Valkey this is typically one MSET. Locmem is enough for tests and a single process.
After one GlobalConfig row is saved and its transaction commits, Django-GC acquires the shared refresh lock, reads that row, and replaces only its typed cache entry. Other entries are not read or changed. Full snapshot publication remains the recovery and reconciliation mechanism for cache misses, initialization, and the optional periodic task.
is_cache_ready() checks the marker and every declared key as a DTO, without reading the database.