The Deadlock alert indicates that a deadlock occurred on the monitored server. For this alert to display, enable monitoring of non-query activities with capturing of deadlock events.
Deadlocks occur when a process or several processes attempt to access a resource that the other holds a lock on. Neither task can complete because both processes are attempting to lock the same resource.
SQL Server chooses one or more deadlock to terminate so that processing can continue.
Resolve deadlocks
When a Deadlock Alert occurs, check the Alerts view in SQL Diagnostic Manager and select a deadlock alert. The SPID, Hostname, Login Name, Client Application, and Database are listed.
For more information, select Show Deadlock Details. This information helps with diagnosing the problem application and includes the option to export deadlock data to view in SQL Server Management Studio or SQL Server Profiler.
Create an alert response bundle with the Deadlock alert and related alerts. For additional information, see Create alert response bundles.