AWS lets existing ElastiCache Valkey clusters change durability

Amazon Web Services says ElastiCache for Valkey customers can now enable or disable durability on existing node-based clusters without creating a replacement. Previously, customers could not change that configuration in place, complicating moves between caching and persistent storage. Synchronous writes persist data across at least two availability zones before responding, with single-digit millisecond write latency and a design goal of zero data loss. Asynchronous writes preserve microsecond write latency at no additional cost, but a failure could lose up to 10 seconds of uncommitted data. Both retain microsecond read latency. The feature is available wherever ElastiCache for Valkey 9.0 and later is offered.