Active/Active MySQL Configuration

An active/active configuration consists of two or more servers actively running a different database instance with each serving as a backup for each other. The database instances must be on different shared physical disks. For LifeKeeper configurations supporting multiple MySQL database instances (of the same or different versions), SIOS recommends that the mysqld Group feature be used for versions of MySQL that support this feature. For these configurations, the my.cnf configuration file will reside in /etc. For MySQL versions that do not support the mysqld Group feature, the my.cnf configuration file must reside in the MySQL data directory shared file system for each database instance (e.g. in Figure 2 below, /shr1/mysql and /shr2/mysql).

Configuration Notes:

• Each server uses a different MySQL data directory (which includes the database instances (database A and database B) on different shared disks

• The path to the MySQL data directory is different for each instance defined on the server.

• The my.cnf configuration file is located in /etc and contains mysqld group sections for each database instance. Each section defines a unique MySQL data directory, port and socket for that database instance. The my.cnf configuration file must be kept in sync on all nodes in the cluster. For systems running versions of MySQL that do not support mysqld Groups, the my.cnf configuration file for each of the database instances is located on the shared drive in the data directory for the database instance. Each configuration file defines a unique MySQL data directory, port and socket definition for that database instance.

• The MySQL executables are located on a local drive on each server in /usr/bin.

• Initially, Server 1 runs databaseA and Server 2 runs databaseB. In a switchover situation, one server can run both databases.

Creating the first resource hierarchy on Server 1:

Extending the first resource hierarchy to Server 2:

Creating the second resource hierarchy on Server 2:

Extending the second resource hierarchy to Server 1:

Configuration Notes:

• Each server uses a different MySQL data directory (which includes the database instances (database A and database B) on different shared disks

• The path to the MySQL data directory is different for each database instance defined on the server.

• The my.cnf configuration file is located in /etc and contains mysqld group sections for each database instance. Each section defines a unique MySQL data directory, port and socket for that database instance. The my.cnf configuration file must be kept in sync on all nodes in the cluster. For systems running versions of MySQL that do not support mysqld Groups, the my.cnf configuration file for each of the database instances is located on the shared drive in the data directory for the database. Each configuration file defines a unique MySQL data directory, port and socket definition for that database instance.

• There is a copy of the MySQL executables on each of the shared disks that contains the data directories.

• Initially, Server 1 runs databaseA and Server 2 runs databaseB. In a switchover situation, one server can run both database instances.

Creating the first resource hierarchy on Server 1:

Extending the first resource hierarchy to Server 2:

Creating the second resource hierarchy on Server 2:

Extending the second resource hierarchy to Server 1: