Shared State

To configure an EMS server as a fault-tolerant secondary, set 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 secondary server.
  • ft_active    In the configuration file of the primary server, set this parameter to the URL of the secondary server. In the configuration file of the secondary server, set this parameter to the URL of the active server.

When a server configured for fault tolerance starts, it attempts to connect to its peer server. If it establishes a connection to its peer, then it enters the standby state. If it cannot establish a connection to its peer, then it becomes the active server.

While a server is in the standby state, it does not accept connections from clients. To administer the standby server, the admin user can connect to it using the administration tool. Standby servers started with a JSON configuration file cannot be administered.