Remembers (installId, nonce) pairs and refuses a repeat. Each entry lives 602 s by default:
the ±300 s clock-skew window plus 2 s, because the skew check compares whole seconds.
Expired entries are swept when the cache grows.
When full of live entries it refuses new nonces (fail closed).
The cache is per process. A collector that runs more than one instance needs a shared store
(for example Redis SET NX EX) so a nonce seen by one instance is refused by the others.
Remembers
(installId, nonce)pairs and refuses a repeat. Each entry lives 602 s by default: the ±300 s clock-skew window plus 2 s, because the skew check compares whole seconds. Expired entries are swept when the cache grows. When full of live entries it refuses new nonces (fail closed).The cache is per process. A collector that runs more than one instance needs a shared store (for example Redis
SET NX EX) so a nonce seen by one instance is refused by the others.