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ProxySQL 2.4.2 and proxysql admin tools (2022-08-10)

ProxySQL is a high-performance proxy for MySQL and MySQL-compatible database servers such as Percona Server for MySQL and MariaDB. It acts as an intermediary for client requests seeking resources from the database. ProxySQL was created for DBAs as a means of solving complex replication topology issues.

You can download the original ProxySQL from GitHub. The ProxySQL documentation provides information on installing and running ProxySQL.

The ProxySQL Admin (proxysql-admin) tool simplifies the configuration of Percona XtraDB Cluster nodes with ProxySQL. ProxySQL Admin 1.x.x requires custom Bash scripts to track the status of a Percona XtraDB Cluster. ProxySQL Admin 2.x.x supports Percona XtraDB Cluster without custom scripts.

The Percona Scheduler Admin (percona-scheduler-admin) tool can automatically perform a failover due to node failures, service degradation, or maintenance.


Percona Scheduler admin has different features and capabilities then ProxySQL admin. Do not use the options from one tool in the other tool. Mixing the options may cause unintended results.

Release highlights

This release includes all features and bug fixes available in ProxySQL 2.4.0, ProxySQL 2.4.1, and ProxySQL 2.4.2.

Improvements and bug fixes introduced by ProxySQL and included in this release are:

  • Adds transaction_isolation to the list of session variables that do not disable multiplexing in ProxySQL
  • Improves the startup time when multiple listeners are configured
  • Improved code quality

For more information on the issues fixed, features, or enhancements, see the ProxySQL 2.4.0 release notes, the ProxySQL 2.4.1 Release notes, and the ProxySQL 2.4.2 Release notes.

ProxySQL Admin and Percona Scheduler admin have not changed since the previous release.


An upgrade from ProxySQL v1.x to ProxySQL v2.x requires the user to manually remove the ProxySQL v1.x packages. After that operation, the user can install ProxySQL v2.x.


When pxc_scheduler_handler launches, a lock file is created to prevent the running of multiple instances of pxc_scheduler_handler. Previously, the lock file remained in the file system and prevented the handler script from running.

Now, on startup, pxc_scheduler_handler does the following:

  • reads the Process identifier (PID),
  • reads the timestamp from the lock file,
  • checks if PID is running on startup.

If PID is still running, the newly launched pxc_scheduler_handler exits. If the PID is not running, pxc_scheduler_handler checks whether the timeout specified in lockFileTimeout exceeds. If the timeout exceeds, pxc_scheduler_handler removes the lock file and performs the operations.

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Last update: 2024-04-18