Doctrine ORM and Redis Cache: Concurrency Latency during Cache Stampede Prevention

Doctrine ORM implements a second-level cache (SLC) to reduce database load. To prevent cache stampedes, the system employs a locking mechanism when multiple concurrent requests encounter a cache miss for the same entity. This mechanism relies on the underlying cache adapter's atomic operations, such as the SET NX EX command when using a Redis backend.

Under high concurrency, the network round-trip required for these atomic locks can introduce observable latency. While the cache lock timeout is configurable, the current implementation uses a fixed value that may not align with varying workload patterns or write-through frequencies.

Integration Constraints

• Environment: Doctrine ORM 2.18+ with a Redis cache adapter.
• Behavior: Latency spikes appearing specifically during concurrent requests for the same entity.
• Dependency: Network overhead associated with the PHP Redis extension and Redis server response times.

Does Doctrine provide a mechanism for an adaptive back-off strategy or a dynamic timeout for these cache locks to mitigate serialization latency? If not, what is the recommended approach to handle lock contention without manually tuning a global fixed timeout?