# v5.1.5-build.3

## Enhancements

- [#10697](https://github.com/emqx/emqx/pull/10697) This change allows to set the minReadySeconds for the StatefulSet. This allows to add a gap between the restarts of each pod by upgrade or restart command.

- [#11390](https://github.com/emqx/emqx/pull/11390) Add `node.broker_pool_size`, `node.generic_pool_size`, `node.channel_cleanup_batch_size` options to EMQX configuration.

  Tuning these options can significantly improve performance if cluster interconnect network latency is high.

- [#11389](https://github.com/emqx/emqx/pull/11389) Improved retained message publishing latency by consolidating multiple index update operations into a single mnesia activity, leveraging the new APIs introduced in mria 0.6.0.

- [#11399](https://github.com/emqx/emqx/pull/11399) Improved the placeholder syntax of rule engine.

  The parameters of actions support using placeholder syntax to
  dynamically fill in the content of strings. The format of the
  placeholder syntax is `${key}`.
  Before this improvement, the `key` in `${key}` could only contain
  letters, numbers, and underscores. Now the `key` supports any UTF8
  characters.

- [#11405](https://github.com/emqx/emqx/pull/11405) Improve the error reason of the `date_to_unix_ts` to make more sense.

## Bug Fixes

- [#11279](https://github.com/emqx/emqx/pull/11279) Prevent client disconnected when sending large payloads with debug/trace logging is enabled.

- [#11388](https://github.com/emqx/emqx/pull/11388) Increase `emqx_router_sup` restart intensity.

  The goal is to tolerate occasional crashes that can happen under relatively normal conditions
  and don't seem critical to shutdown the whole app (emqx).
  For example, mria write/delete call delegated from a replicant to a core node by `emqx_router_helper` may fail,
  if the core node is being stopped / restarted / not ready.

- [#11410](https://github.com/emqx/emqx/pull/11410) Reintroduce `cacerts` TLS client option as a deprecated option.

  This fixes issues found when trying to upgrade from 5.1.3 where that option is set in the configuration files or persisted in EMQX Operator settings.