Updates on a Schedule

CAU supports different update modes in which you can schedule updates. With remote updating, you can start an update manually for the cluster. As described above, you can use the user interface for this or use the Cmdlet Invoke-CauRun in PowerShell. The remote upgrade is the default update mode for CAU. With the task scheduler, you can also start the Cmdlet at a time that suits you as specified in a schedule. Make sure, however, not to use a cluster node; instead, use a server running Windows Server 2012 (R2) that is not a member of a cluster.

With the self-update function, the cluster based on a defined profile can update itself automatically. If you want to enable the self-update mode, add the CAU cluster role to the cluster, as described above. The CAU self-update feature works like any other cluster service. You can also use it for planned and unplanned failovers.

By default, CAU uses the level of activity to determine the sequence of nodes to be updated. The service first updates the nodes on which the fewest cluster roles are hosted, but you can specify a sequence. To do this, use the settings in the CAU user interface. With options, you determine the number of nodes that may be offline if CAU starts the update. CAU also provides export options via PowerShell and the user interface. The commands in PowerShell are typically faster:

Invoke-CauScan | ConvertTo-XmlGet-CauReport | Export-CauReport

The CAU Cmdlets and graphical user interface are available if you have installed the Failover Cluster Management Tools. You can use both the Server Manager and the Remote Server Administration Tools (RSAT) for Windows 8.1 [2].

If you want to download the updates from the Internet, but the cluster has no direct connection to the Internet, you can also use a proxy server. You can, for example, set preferences in the command line using netsh:

netsh winhttp set proxy [name]

or

netsh winhttp set proxy [proxy]:[port] "<local>;*.[domain]"

In the command, enter the name or the IP address and proxy port, with the exceptions in quotation marks. Here, enter your internal domain, as well as the option <local> to configure all local servers as an exception.

Conclusion

Companies often face the question of how to update clusters. Cluster-Aware Updating is a valuable tool if no maintenance windows are available. No lengthy failures occur, because the cluster resources are enabled on other servers. However, make sure all cluster nodes in the network can cope with the additional load if a node is shut down for upgrades and its resources are distributed in the cluster.