I am getting the alerts from SQL Diagnostic manager, session id blocking for 300 seconds.It doesn't look like that particular session id is active and it looks to me false alert. The blocking time is not increasing and the blocking happened once. But not sure why it keep sending the same alert even after there is no blocking.I am using 10.1 version. Has anyone came across this issues? How to fix the false alert. Please advise?
In SQLDM, Activity Monitor is the feature that captures blocking events. This feature gathers data either through Extended Events or a SQL Server Profiler trace (depending on how you configure it and the version of SQLDM you are on).
I've seen some scenarios where either the extended event file or the profiler trace file becomes corrupted. In such scenarios, SQLDM ends up reading the old data over and over and generating alerts based on the old data. What you can try doing is the following:
Give that a try and see if you continue to have the issue you reported.