* fix(router): keep the prompt caching affinity pin alive as long as the prefix's cache_control ttl
A prefix marked cache_control ttl 1h lost its pinned deployment after the fixed 300 s, so the next request went to another deployment and paid a cold cache. The pin TTL now follows the longest ephemeral breakpoint in the cacheable prefix, tools included: 3600 s for a 1h breakpoint and 300 s otherwise.
* fix(router): give prompt cache pins their own tier and honour any declared ttl
Pins now live in a DualCache of their own instead of the router's 200-slot
in-memory tier, so an hour-long pin no longer evicts cooldowns and rate windows.
The pin lifetime follows any <n>s|m|h cache_control ttl, floored at 300 s, not
only the literal "1h".
* fix(router): hash the pin ttl off the event loop and flush prompt cache pins with the router cache
Compute the cache_control ttl scan through offload_token_count beside the
prefix hash, clear the dedicated pin cache in Router.flush_cache, and point
the order-fallback and priority-group pin tests at the pin cache they read
* fix(router): pin 1h prefixes only on 1h-capable models, cap the pin at 1h, and give pins 10k in-memory slots
* fix(router): match the 1h pin gate to what Bedrock forwards
Bedrock deployments now decide the 1h pin with is_claude_4_5_on_bedrock,
the same check that decides whether the 1h ttl reaches Bedrock, so an
application inference profile ARN keeps a 5 minute pin whatever its
base_model prices
* test(router): give the anthropic_messages pin fixture its provider
* fix(router): let each pin write set its own lifetime and require a positive 1h price
In a group mixing 1h and 5m deployments the in-memory pin kept the lifetime of its first write, so a 5m deployment could hold an hour-long pin. Each write now clears the in-memory entry first, matching Redis. The Bedrock gate uses supports_bedrock_prompt_cache_ttl after #46058, and a zero 1h price no longer counts as 1h support.
* test(router): integration cells for the one-hour prompt cache pin lifetime
Cover every surface the pin lifetime touches: chat and /v1/messages through
both SDKs, the responses bridge, response-cache hits, each provider family's
1h gate, malformed and duplicated ttl values, rewrites of one prefix, mixed
and cross-group routing, concurrency, every Redis attach path, the in-memory
slot pressure without Redis reads, a Redis outage and a killed worker
* fix(caching): bound the in-memory expiry heap and count prompt cache pins in the memory debug routes
* test(integration): cover prompt cache pins in the memory debug routes and the bounded expiration heap
* fix(caching): serialize in-memory cache writes so a heap rebuild cannot lose another thread's expiry entry
* fix(caching): keep the in-memory cache bounded when entries have no usable expiry
* test(caching): cover the response cache bound when cached entries have no usable ttl
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Co-authored-by: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
