Build the pxc_scheduler_handler tool¶

In an MySQL 8.4 or Percona Server for MySQL 8.4 environment, you may have the following issues:

ProxySQL contains counters that have not been updated to use the new terminology. Unexpected results may occur
The binlog reader errors out during initialization due to the use of the old terminology, such as SHOW MASTER STATUS command.

The pxc_scheduler_handler tool has two main files: the pxc_scheduler_handler binary and the percona_scheduler_admin script.

The pxc_scheduler_handler does the following tasks:

Monitors the cluster health
Processes the cluster state and evaluates the scenario
Performs actions, such as failover in case of an incident

The percona_scheduler_admin script runs and provides responses based on the configuration file for the pxc-scheduler_handler binary.

Running pxc_scheduler_handler without percona_scheduler_admin requires manual intervention.

Cloning a git project that contains submodules does not automatically check out the submodule content. The submodules require initialization and updating before they are functional.

Build the module¶

You can perform the submodule initialization by running the following statement:

$ git submodule update --init

Run the following command to build the scheduler submodule.

$ build_scheduler.sh

The pxc_scheduler_handler binary is located in the base directory.

We do not recommend running multiple instances of the same binary. If you start a new instance when an instance of pxc_scheduler_handler is already running, the binary runs, but the second instance does the following:

Consumes network and system resources
Returns the same results since multiple versions use the same configuration file

Create an account¶

Create an admin user account. Use this account for communication through ProxySQL and pxc_scheduler_handler.

The following example uses the mysql_native_password authentication method to create an admin user account:

mysql> CREATE USER 'admin'@'192.%' IDENTIFIED WITH 'mysql_native_password'
by 'admin';

If you are using a ProxySQL version 2.6.2 or later, you can use the caching_sha2_password authentication method. The following example creates an admin user account using that method:

mysql> CREATE USER 'admin'@'192.%' IDENTIFIED WITH 'caching_sha2_password' BY 'admin';

Grant privileges to the admin user account:

mysql> GRANT ALL PRIVILEGES ON *.* TO 'admin'@'192.%' WITH GRANT OPTION;