ProxySQL

ProxySQL provides loadbalancing to MariaDB. Prior to 2025.1 release, HAProxy was the default loadbalancer for database like other services. But from 2025.1, the ProxySQL became the default and the support for HAProxy as a database loadbalancer will be discontinued from 2025.2.

Note

If your MariaDB cluster is not managed by Kolla-Ansible, this is not applied.

Migrating from HAProxy

The migration is automatically handled by Kolla-Ansible. By default, ProxySQL gets enabled when MariaDB is enabled from 2025.1 release. So, if users are coming from 2024.1 or 2024.2 release, they can simply run service upgrade command.

Upgrading ProxySQL from 2.7.x to 3.0.x

The default version of ProxySQL for 2025.1 release is 2.7.x however this version of ProxySQL has a bug that it does not send all certificate chain during SSL handshake. See ProxySQL issue 4877 for more detail. This bug was fixed on ProxySQL 3.0.x but not in 2.7.x release.

This bug does not affect users system unless they use chain of certificates for database TLS (e.g. Use of intermediate certificate) If however, this does affect your system, you can upgrade your ProxySQL by following.

  1. Set proxysql_version to 3

proxysql_version: 3

  1. Run service deployment for loadbalancers

$ kolla-ansible deploy -i <inventory> -t loadbalancer

  1. Verify the version of ProxySQL after deployment

$ docker exec proxysql proxysql --version
$ ProxySQL version 3.0.5