v2.11.6

nats-io/nats-serverv2.11.6Jul 1, 2025by github-actions[bot]

AI Summary

This is a maintenance release of NATS Server v2.11.6 focusing on bug fixes and performance improvements, particularly in JetStream. The release updates Go to 1.24.4 and addresses several critical issues including a filestore encryption corruption bug and a performance regression in filtered consumers.

Key Highlights

Updated Go version to 1.24.4
Fixed critical filestore encryption corruption bug when writes occur before reads after server restart
Resolved performance regression in filtered consumers introduced in v2.11.0
Improved consumer performance by reducing allocations and optimizing pending calculation
Fixed race condition where removed streams could incorrectly reappear

Full Release Notes

## Changelog

Refer to the [2.11 Upgrade Guide](https://docs.nats.io/release-notes/whats_new/whats_new_211) for backwards compatibility notes with 2.10.x.

### Go Version

- 1.24.4

### Improved

JetStream

- Sources will no longer update their last seen timestamp when stalled, making it clearer how long it has been since the last contact (#7013)
- Overall consumer performance has been improved by reducing allocations and improving the num pending calculation (#7022)

### Fixed

General

- The `subsz` monitoring endpoint now returns the correct `total` for subscription details, aligning behaviour with other endpoints for pagination (#7009)

JetStream

- Fixed a bug where filestore encryption could corrupt a message block if a write took place before a read after restarting the server (#7008)
- Fixed a performance regression introduced in v2.11.0 which could result in abnormally low throughput from filtered consumers and higher GC pressure (#7015)
- Healthchecks will no longer produce unexpected monitor goroutine warnings when a clustered stream is restored from a snapshot (#7019)
- A race condition that could result in removed streams incorrectly reappearing has been fixed (#7025)
- The `reserved_memory` and `reserved_storage` statistics will no longer underflow when no limits are set (#7024)

### Complete Changes
 
https://github.com/nats-io/nats-server/compare/v2.11.5...v2.11.6