In the Console, you can trigger on certain states in the JVM and perform an action this is met. E.g. send an email when the CPU > 80%.
One action you can chose is to have an alert. JMC will then simply log an alert, which you can see in the Trigger Alert dialog. The default setting is also to show the dialog when a new alert arrives.
However, I remember that we discussed that this dialog should be used more often. If you e.g. dump the threads to a file when the trigger goes off, it will work only once. The next time the trigger goes off, you will get an exception since the file exists already. This is an example of when an extra alert is very useful.
In JMC 6.0.0-644, this doesn't seem to be working properly. You do get an extra alert e.g. when the situation described above happens, but the dialog is not displayed. But sometimes it is! You may need to wait for 30 minutes before the dialog is actually displayed.
Evergreen performed tests of this in the ATR-2 test round for JMC 6.0.0 and the results where mixed (mostly failed).
I suggest that we have a closer look at this feature and make sure it works consistently as a user would expect.