SOLVED: Exchange Connection Leak Detected For Key

If you see this message in your event logs or reporting tools, you likely have some simple work to do:

Eventsource: Windows Exchange Events
Windows Event ID: 74
Message: (Process w3wp.exe, PID 11936) Connection leak detected for key URtech.ca/URTech/Calgary/Users/IT/Ian Mat in Microsoft.Exchange.Configuration.Authorization.WSManBudgetManager class. Leaked Value 1

This event is logged when the system detects that a connection is not being properly released, which can lead to resource exhaustion over time and crash your Exchange Server.

Fortunately it is easy to track down and correct the connection leak:

As you can see we ran a simple PowerShell command Get-Process | Sort-Object ID | Select-Object Name, Id to see the problem was with W3WP.exe which was not required but we wanted to understand everything else that was running because TASK MANAGER was not showing the PID in question.

The fix was to:

1. Launch IIS
2. Click on the the server name, in the CONNECTIONS pane on the left
3. Double click on WORKER PROCESSES
4. Locate the matching PID (in our case 11936) to determine the IIS Application Pool that was leaking
5. Expand APPLICATION POOLS
6. Right click on the offending pool and select RECYCLE
7. Have a nice day