Server redundancy

The Symphony Server supports server redundancy in server farms. If the primary Symphony Server stops responding, the camera and device processing moves to a redundant Symphony Server.

To use server redundancy you must have at least one primary Symphony Server and one redundant Symphony Server in a redundancy group. The primary Symphony Server actively performs camera and device processing. The redundant Symphony Server is active, but it does not have any cameras or devices associated with it. There must be at least one redundant server available in the server farm at all times.

When failover occurs, the redundant Symphony Server takes over the camera and device processing from the primary Symphony Server while it is unavailable. When the primary Symphony Server recovers from the outage, one of the following things happens:

You can move the camera and device processing back to the primary Symphony Server automatically by enabling failback in the Symphony Server configuration interface.
You can move the camera and device processing back to the primary Symphony Server manually by swapping servers in the Symphony Server configuration interface.
You can use the primary Symphony Server as a redundant Symphony Server.

In a redundancy group, one Symphony Server is the master server. The master server performs the additional task of managing failover and failback operations. If the master server is unavailable, another Symphony Server in the redundancy group becomes the master server. You can manually select the master server by selecting the star icon beside the Symphony Server on the Servers page in the Symphony Server configuration interface.