a customer is using an ESB from "Software AG", which we instrumented as Java Application tier. The JVM is started with that java version (output from java -version of that respective JVM java):
java version "1.7.0"
Java(TM) SE Runtime Environment (build pxz6470sr4fp1-20130325_01(SR4 FP1))
IBM J9 VM (build 2.6, JRE 1.7.0 Linux s390x-64 Compressed References
20130306_140761 (JIT enabled, AOT enabled)
Hot sensor placement is not available of that tier (setting is "Automatic"), because it is a J9 VM from IBM.
I checked this page: Hot Sensor Placement
and it says "Disabled by default. You can enable it manually in the in the Advanced Settings section of the Agent Mapping." for the IBM java. Just wanted to check before I activate it, if this is actually good. I mean what does "You can" mean in that case...Is it save to do so? What could be the issue? I guess there is a reason why it is deactivated by default
From my experience with an IBM JVM, the hot sensor placement would just fail. It didn't cause me any trouble on my applications it just didn't work (it would get stuck for 5 minutes then just fail).
If it's not a production application I guess you could try it, if you can't then just try to work with the scheduled reboots. I didn't see any workaround with this and I had a support case open as well.
Hope this helps,