Two Servers Become the Master Server

If communications completely fail between the two redundancy managers, both servers can initiate a failover event. In this case, each computer becomes the master server.

If both computers become the master server, batch control is not guaranteed, and operator intervention is mandatory. Avoiding this situation is a primary requirement when you deploy a redundant batch system.

The communication failure between redundancy managers can occur for several reasons, such as the following examples:

• The simultaneous loss of both communications channels for a period of time at least equal to the switch-over setting

• Any batch server process that completely consumes system resources (such as CPU or network throughput)

To prevent both servers from becoming the master server, it is recommended that you:

• Ensure that you have allocated adequate resources for the Batch Management System.

• Disable screen savers on the AVEVA Batch Management Server because they are resource-intensive.