This script monitors that two instances of SQL are not running on the same node in an active/active cluster configuration. I run this as a SQL Server Agent job every 30 minutes.
*xp_cmdshell must be enabled
*best to run it from a server that is not a member of the cluster
*change @svrName to your server
*change #tmpTable names to match your server
This script can also be easily modified to use a cursor and read from a table if you have multiple active/active clusters