Distributed Architecture with Distribution Servers

In a distributed architecture using distribution servers, you can also implement HA for the central server. (See Distributed Architecture for a detailed description of distributed architecture.) All TOS applications run on the active central server. A second central server is set up as the standby central server.

The two central servers use the heartbeat interface to determine the liveness of the other server. When communication fails on the heartbeat connection, the standby central server becomes the new active central server.

The central servers must be configured to use a VIP address, to allow traffic to be redirected to the currently active HA server. All communication from the distribution servers to the central server will use the VIP address, ensuring that traffic is always directed to the currently active HA central server.

The central server can be set up for HA. The distribution servers cannot be set up for HA.