# v5.2.0

## Enhancements

- [#11469](https://github.com/emqx/emqx/pull/11469) Added support for specifying username in Redis authentication.

- [#11487](https://github.com/emqx/emqx/pull/11487) The bcrypt work factor is limited to the range 5-10, because higher values consume too much CPU resources.
  Bcrypt library is updated to allow parallel hash evaluation.

- [#11496](https://github.com/emqx/emqx/pull/11496) Disabled the Erlang VM Prometheus exporter by default to improve performance and security.

- [#11497](https://github.com/emqx/emqx/pull/11497) Enhanced broker metrics collection and export by adding new metrics for messages, overload protection, authorization, authentication, and improving naming consistency for OpenTelemetry.

- [#11490](https://github.com/emqx/emqx/pull/11490) Added fast error handling for undefined passwords in various authentication backends. This improves the consistency and user-friendliness of the authentication process.

- [#11532](https://github.com/emqx/emqx/pull/11532) Improve some error reasons when parsing invalid packets.

## Bug Fixes

- [#11466](https://github.com/emqx/emqx/pull/11466) Fixed a crash that occurred when setting the `ssl_options.ciphers` configuration option to an empty string ("").

- [#11480](https://github.com/emqx/emqx/pull/11480) Improves the error handling and testing of SQL functions in the rule engine when rule functions receive bad arguments.

- [#11493](https://github.com/emqx/emqx/pull/11493) Examples and documentation for /api/v5/publish bad request response have been fixed. Previously the documentation example said that the bad request response could return a list in the body which was not actually the case.

- [#11506](https://github.com/emqx/emqx/pull/11506) Avoid downloading a trace log file if it is empty.

  After this fix, GET `/api/v5/trace/clientempty/download` returns 404 `{"code":"NOT_FOUND","message":"Trace is empty"}`
  If no events matching the trace condition occurred.

- [#11520](https://github.com/emqx/emqx/pull/11520) Fixed issue where `packets_connack_sent` metric was not incremented on CONNACK packets sent with non-zero `ack_flag`.

- [#11522](https://github.com/emqx/emqx/pull/11522) Improved error message for rule engine schema registry when schema name exceeds permissible length.

- [#11523](https://github.com/emqx/emqx/pull/11523) Corrected a misleading prompt when specifying invalid certificates/keys for the `/configs` API.

- [#11531](https://github.com/emqx/emqx/pull/11531) Fixed issue where authorization cache cleaning cli was not working properly for specific client ID.

- [#11534](https://github.com/emqx/emqx/pull/11534) Fixed the increment on data bridge statistics when the bridge is unhealthy. Now, messages sent to unhealthy bridges are counted as dropped messages.

- [#11540](https://github.com/emqx/emqx/pull/11540) Improved HTTP response when attempting to create a bridge with an invalid name.

- [#11548](https://github.com/emqx/emqx/pull/11548) Fixed an issue that prevented the plugin order from being updated across the entire cluster.

- [#11564](https://github.com/emqx/emqx/pull/11564) Fix cluster partition autoheal functionality. Implement autohealing for the clusters that split into multiple partitions.