Configuring the Fault Tolerant Servers

To configure an EMS server as a fault-tolerant backup, set these parameters in its main configuration file (or on the server command line):

• server Set this parameter to the same server name in the configuration files of both the primary server and the backup server.
• ft_active In the configuration file of the primary server, set this parameter to the URL of the backup server. In the configuration file of thebackup server, set this parameter to the URL of the primary server.

When the backup server starts, it attempts to connect to the primary server. If it establishes a connection to the primary, then the backup server enters standby mode. If it cannot establish a connection to the primary, then the backup server assumes the role of the primary server (in active mode). While the backup server is in standby mode, it does not accept connections from clients.

To administer the backup server, the admin user can connect to it using the administration tool

When a backup server assumes the role of the primary server during failover, clients attempt to reconnect to the backup server (that is, the new primary) and continue processing their current message state. As each client reconnects, the backup server reads its message state from the shared state files. You can instruct the server to clean up state information for clients that do not reconnect before a specified time limit.

The ft_reconnect_timeout configuration parameter specifies that time limit (in seconds). The default value is 60 seconds