# v5.3.0

## Enhancements

- [#11597](https://github.com/emqx/emqx/pull/11597) Upgraded ekka to 0.15.13, which incorporates the following changes:
  - Upgraded Mria to 0.6.2.
  - Introduced the ability to configure the bootstrap data sync batch size, as detailed in [Mria PR](https://github.com/emqx/mria/pull/159).
  - Enhanced the reliability of mria_membership processes, as described in [Mria PR](https://github.com/emqx/mria/pull/156).
  - Fix log message formatting error.
  - Added `node.default_bootstrap_batch_size` option to EMQX configuration.
  Increasing the value of this option can greatly reduce a replicant node startup time, especially when the EMQX cluster interconnect network latency is high and the EMQX built-in database holds a large amount of data, e.g. when the number of subscriptions is high.
- [#11620](https://github.com/emqx/emqx/pull/11620) Added a new rule-engine SQL function `bytesize` to get the size of a byte-string. e.g. `SELECT * FROM "t/#" WHERE bytesize(payload) > 10`.
- [#11642](https://github.com/emqx/emqx/pull/11642) Updated to quicer version 0.0.200 in preparation for enabling openssl3 support for QUIC transport.

## Bug Fixes

- [#11682](https://github.com/emqx/emqx/pull/11682) Fixed an issue where logging would stop if "Rotation Size" would be set to `infinity` on file log handlers.
- [#11567](https://github.com/emqx/emqx/pull/11567) Improve EMQX graceful shutdown (`emqx stop` command):
  - Increase timeout from 1 to 2 minutes.
  - Printed an error message if EMQX can't stop gracefully within the configured timeout.
  - Print periodic status messages while EMQX is shutting down.
- [#11584](https://github.com/emqx/emqx/pull/11584) Fixed telemetry reporting error on Windows when os_mon module is unavailable.
- [#11605](https://github.com/emqx/emqx/pull/11605) Lowered CMD_overridden log severity from warning to info.
- [#11622](https://github.com/emqx/emqx/pull/11622) Upgraded rpc library gen_rpc from 2.8.1 to 3.1.0.
- [#11623](https://github.com/emqx/emqx/pull/11623) Upgraded library `esockd` from 5.9.6 to 5.9.7. This upgrade included:
  * Enhancements regarding proxy protocol error and timeout. [esockd pr#178](https://github.com/emqx/esockd/pull/178)
  * Lowered `ssl_error` exceptions to info-level logging. [esockd pr#180](https://github.com/emqx/esockd/pull/180)
  * Malformed MQTT packet parsing exception log level is lowered from `error` to `info`.
  * In command `emqx ctl listeners` output, the `shutdown_count` counter is incremented
  when TLS handshake failure (`ssl_error`) or Malformed packet (`frame_error`) happens.
- [#11661](https://github.com/emqx/emqx/pull/11661) Fixed log formatter when log.HANDLER.formatter is set to 'json'. The bug was introduced in v5.0.4 where the log line was no longer a valid JSON, but prefixed with timestamp string and level name.
- [#11667](https://github.com/emqx/emqx/pull/11667) Disable access to the `logout` endpoint by the API key, this endpoint is for the Dashboard only.