Keys, concurrency, and invalidation
Archived Based on Bluetape4k release 1.11.0
Do not use toString() as a key
Section titled “Do not use toString() as a key”Hibernate keys contain the entity or role name, tenant, identifier kind, and value. StorageAccess writes a canonical byte sequence, hashes it with SHA-256, and prefixes the digest with hck2:.
kind + entityOrRoleName + tenant presence/value + typed identifier → SHA-256 → hck2:<base64url digest>A scalar "[1, 2]" and an object array [1, 2] remain distinct, as do a delimiter-containing natural ID and a multi-value natural ID. Tests also cover composite IDs, primitive arrays, and custom IDs with equal toString() output.
Match strategy to the data contract
Section titled “Match strategy to the data contract”The factory default is NONSTRICT_READ_WRITE. Updates evict entries and later reads refill them instead of coordinating a strict distributed soft lock. It fits read-heavy data that permits a short stale window.
The suite also covers READ_WRITE, but its Redis soft-lock costs and failure behavior need measurement. A lock marker may remain after delete, so the test explicitly evicts before checking containment. Reserve READ_ONLY for immutable reference data.
RESP3 CLIENT TRACKING
Section titled “RESP3 CLIENT TRACKING”With use_resp3=true, the factory selects RESP3 and Near Cache starts a tracking listener. A change through another Redis connection should push invalidation to the corresponding L1 key.
Tracking startup failure is warning-only:
CLIENT TRACKING start failed, cache will work without invalidationUntil TTL or Hibernate eviction, another process may then retain a stale L1 value. Monitor startup logs and run a multi-instance invalidation test. Setting use_resp3=false for Redis older than 6 gives up this cross-process path.
Avoid direct Redis writes
Section titled “Avoid direct Redis writes”CLIENT TRACKING does not make Hibernate region keys a public mutation API. The versioned key format, query timestamps, and transaction-completion rules are internal. Route changes through Hibernate and SessionFactory.cache.evict*.