The most important aspects of the SMS HA cluster are the heartbeat connection and database replication. Periodically verify that both activities are performing as expected. If you need to upgrade SMS software or apply an SMS patch, you must break apart the cluster and upgrade or patch each of the two SMS HA cluster nodes independently. One of the nodes is always passive, so the SMS software is not fully operational and cannot be upgraded or patched.
If you need to perform maintenance on the active SMS server, for example, to swap out a network card, you can invoke a failover on the active node, which deactivates it and activates the passive SMS server. Once deactivated, you can take the node offline, power it off, and perform maintenance on it. Two methods are available in the Admin -> High Availability screen to deactivate the currently active SMS server:
Swap - swaps the roles of the SMS HA cluster nodes so that the passive SMS server becomes the active SMS server and the active SMS server is reconfigured as the passive server. This process resynchronizes and restarts the nodes to ensure that HA status of the cluster is maintained. This process involves a temporary disconnect of the client and is temporarily more disruptive than failover.
Failover - invokes a failover of the active node in the SMS HA cluster, thereby activating the passive SMS server making it immediately available for use. To bring the failed-over node back online and reinstate a fully functioning HA cluster, you must manually synchronize and restart the deactivated node.
Active SMS- In the Active SMS area of the High Availability screen, the SMS displays the system name, status, maintenance IP address, and heartbeat IP address of the active SMS server. To change the roles of the active and passive nodes or deactivate an active SMS server, see the tasks described in the Passive SMS section.
Passive SMS- In the Passive SMS area of the High Availability screen, the SMS displays the system name, status, maintenance IP address, and heartbeat IP address of the passive SMS server. From within this area you can manually activate the passive SMS server, which in turn deactivates the current active SMS server if it is operational, by invoking a failover. You can also swap roles of the active and passive SMS servers.
Procedure:
This task describes how to activate a passive SMS server and immediately begin using it as the active SMS server. This action is useful when performing maintenance tasks on the active node. To return the failed-over node to active status, you must manually resynchronize and restart the server.
- Log in to the SMS from a client.
- On the SMS toolbar, navigate to the Admin > High Availability tab.
- In the Passive SMS area, click Failover.
- When the dialog box appears, select OK to invoke failover and activate the passive SMS server.
The active server fails over to the passive server, which becomes your active server. You can power off the deactivated server and perform maintenance. To reactivate your passive server and reinstate your cluster to a fully functioning high-availability state, you must bring the deactivated server back online, synchronize the cluster databases, and restart the server.
Reference: SMS User Guide