Sometimes SQL Database administrators want to check whether given SQL Server instance is in clustered environment. The SERVERPROPERTY() built in metadata system function can be used to identify the clustered mode. SERVERPROPERTY() function with IsClustered Property will return “0” for Standalone mode and “1” for Clustered mode.
SELECT CASE SERVERPROPERTY('IsClustered')
WHEN 0 THEN 'No'
WHEN 1 THEN 'Yes'
END as [Is this SQL Server Clustered ?]