v2.14.1
nats-io/nats-serverv2.14.1May 20, 2026by github-actions[bot]
AI Summary
A maintenance release focused on performance improvements and bug fixes, particularly in JetStream operations and general server stability. It introduces new metrics for tracking client traffic and resolves various CPU usage and memory leak issues.
Key Highlights
- New monitoring metrics for tracking data to/from normal clients (`in_client_msgs`, `in_client_bytes`, etc.)
- Improved JetStream performance by only calculating Num pending on consumer leaders and cancelling early sublist intersections
- Fixed numerous memory leaks in JetStream snapshots, catchup loops, and Raft operations
- Improved TLS and Leafnode handling, including PROXY protocol support and compression logic fixes
Full Release Notes
## Changelog Refer to the [2.14 Upgrade Guide](https://docs.nats.io/release-notes/whats_new/whats_new_214) for backwards compatibility notes with 2.12.x. Please note that the 2.13.x version was skipped. ### Go Version - 1.26.3 (#8107) ### Dependencies - github.com/klauspost/compress v1.18.6 (#8124) - golang.org/x/crypto v0.51.0 (#8124) - golang.org/x/sys v0.44.0 (#8124) ### Added General - New metrics `in_client_msgs`, `in_client_bytes`, `out_client_msgs` and `out_client_bytes` are now available via the `/varz` monitoring endpoint for tracking data to/from normal clients only (#7851) ### Improved General - Client TLS certificates without subject DNs but with DNS subject alternate names are now permitted (#8100) - The log level of TLS handshake timeout or non-TLS record errors have been demoted to debug level to reduce noise (#8096) JetStream - Num pending is now only calculated on consumer leaders, avoiding unnecessary CPU usage on followers (#8172) - Snapshot and catchup loops no longer leak timers (#8186, thanks to @SebTardif) - Stream and consumer assignment errors are now surfaced (#8208) - Intersection of sublists and subject trees can now be cancelled early, avoiding high CPU usage in some pathological cases (#8209) ### Fixed General - Cluster route compression now obeys the cluster `max_pings_out` option if configured (#8093) - The internal send loop no longer mutates caller headers, which could corrupt buffers (#8097) - Removing headers no longer fails to remove later headers if the matching prefix also appeared in an earlier header value (#8103) - The sublist now correctly maintains negative results in the cache when calculating number of interested subjects (#8119) - Server shutdown requests are now idempotent, preventing concurrency issues when shutting down in embedded contexts (#8163) - TLS listeners now work correctly with the PROXY protocol where enabled (#8130) - Reduced lock contention that could be created between leafnodes and clients (#8139, #8159) - Fixed a panic that could happen when an error occurs when walking JWT directory resolver folders (#8173, thanks to @SebTardif) - In-process connections will no longer unexpectedly revert to TLS required with async `INFO` (#8205) Leafnodes - Leafnode connections will no longer negotiate compression if they are configured over already-compressed WebSockets (#7969) JetStream - Fast batch now correctly parses the batch sequence as a uint64 (#8094) - Atomic batch no longer double-pools committed entries on cleanup (#8098) - Raft nodes will now ignore temporary snapshots on recovery after a crash (#8101) - A number of paths that could leave consumer redelivered in a drifted state have been fixed, e.g. with workqueue or interest-based streams with `max_deliver`, on single message removal or after purges/compactions (#8102) - Caches are now cleared correctly when converting filestore encryption mode, avoiding block-level corruption (#8105, #8166) - Fixed a race condition when updating the deduplication map on leader change (#8106) - Source consumer creation will no longer schedule a recreation if a setup is already in progress, avoiding potential setup storms (#8111) - Fixed data races when reading from the stream configuration when checking reservations, answering some API requests amongst others (#8115) - Stream republish subjects are now validated correctly (#8127) - The delivery policy for consumers on clustered workqueue streams is now enforced correctly (#8126) - The `Nats-Schedule-Next: purge` action now correctly checks if the target is a schedule (#8135) - Raft node append entry caches are now invalidated correctly on WAL truncation and snapshot installs (#8149) - Skip message errors are now surfaced correctly, propagating failures (#8152) - Mirror consumers are now retried immediately on a last sequence mismatch, avoiding stalling for longer than necessary (#8152) - Raft nodes will no longer allow proposals to remove unknown peers (#8154) - Pending state no longer leaks when reaching max deliveries (#8156) - A panic when reusing a wait group when resetting a stream's clustered state has been fixed (#8158) - Correctly reset local meta log when extending the meta group to a parent domain (#8142) - Consumer file stores will now correctly flush when deleting a single redelivery, avoiding unexpected further redeliveries (#8168) - Storage reservations for un-tiered streams have been made consistent between creates/updates and clustered/non-clustered modes (#8170) - Raft will now correctly cancel an in-flight checkpoint operation when resetting (#8180, #8202) - The `JetStreamMaxMemory` and `JetStreamMaxStore` options are now handled correctly in embedded mode (#8184) - A number of fields that were aliasing underlying filestore block caches have been fixed (#8187) - Consumers with `inactive_threshold` should no longer have their local state deleted unexpectedly when the proposal to the metalayer to clean up the consumer fails (#8198) - Metalayer state is now preserved in a number of cases where it was incorrectly being removed on shutdown (#8199) MQTT - Invalid characters in subjects are now rejected correctly, avoiding protocol issues when forwarded to other connection types (#8104, #8112) ### Complete Changes https://github.com/nats-io/nats-server/compare/v2.14.0...v2.14.1