After using the real-time alerting functionality successfully for a while you notice that alerts take much longer to generate or fail completely.
This can occur when the InTrust Alerts DB gets too large. The InTrust_9.0_BestPractices_032106.pdf doc suggests keeping this less than 3GB or a weeks worth of data (which ever is smaller).
If you have done all other troubleshooting, i.e. checking for events in event log, checking that Quest InTrust Real-time Monitoring service is started, restarting Quest InTrust Agent on remote machine, etc then do the following:
1. Open InTrust Manager | Workflow | Tasks | right-click New Task
2. Using the wizard set the desired name (for the task) schedule and account (default is Quest InTrust Server service account)
3. Click 'Create a job in this task' and Finish
4. Select Alert Database Cleanup, Next, choose your Alert database (usually Default Alert DB ...), Next,
5. Click each of the four Time Unit entries and Status entries and change them to the desired values (usually 1 week and All respectively)
6. Click Next, Next, type in the desired name, click Next and the Finish
This will affect all versions of InTrust