You have to log it on the JVM level or run a JVM monitoring tool. The memory usage graph in FR is a good first indicator but depending on your JVM settings GC might be so minimal that you won't be able to really tell what's going on. Without proper logging you also won't be able to tell if it's been a Full GC or which Generation had triggered it.
Add something like this to your JVM args: -verbose:gc -Xloggc:mylogfile.log -XX:+PrintGCDetails -XX:+PrintGCTimeStamps Note, there are a lot more attributes that control the logging, just depends on what you want and need. Or look for tools like: VisualGC, GCViewer and a lot of others. They all basically help you with one or the other aspect, gain depends on what you want. Cheers Kai On 4/02/2010, at 11:10 AM, Andrew Myers wrote: > Thanks Mark. > > Is anyone able to please tell me how I can identify when garbage > collection is happening? > > On 4 February 2010 07:59, Mark Mandel <mark.man...@gmail.com> wrote: >> Those are the threads in the thread pool waiting to be used. >> >> They aren't doing anything. >> >> Mark >> >> On Thu, Feb 4, 2010 at 12:05 AM, Andrew Myers <am2...@gmail.com> wrote: >>> >>> Ummm....me again :-) >>> >>> I'm seeing about 20 of these in my thread dump. Is anyone able to >>> tell me if they anything to be concerned about? >>> >>> Thread Stack Trace >>> Trace Time: 23:35:12.743 03-Feb-2010 >>> Thread ID: obj-skimmer >>> Priority: 5 >>> Hashcode: 22419531 >>> >>> "obj-skimmer" daemon prio=5 tid=0x00a5a0a0 nid=0x99 in Object.wait() >>> [0x9cb01000..0x9cb019c0] >>> at java.lang.Object.wait(Native Method) >>> - waiting on <0xbedddb30> (a >>> coldfusion.server.j2ee.pool.PoolSkimmerThread) >>> at >>> coldfusion.server.j2ee.pool.PoolSkimmerThread.run(PoolSkimmerThread.java:47) >>> - locked <0xbedddb30> (a >>> coldfusion.server.j2ee.pool.PoolSkimmerThread) >>> at java.lang.Thread.run(Thread.java:534) >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "cfaussie" group. >>> To post to this group, send email to cfaus...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> cfaussie+unsubscr...@googlegroups.com. >>> For more options, visit this group at >>> http://groups.google.com/group/cfaussie?hl=en. >>> >> >> >> >> -- >> E: mark.man...@gmail.com >> T: http://www.twitter.com/neurotic >> W: www.compoundtheory.com >> >> Hands-on ColdFusion ORM Training @ cf.Objective() 2010 >> www.ColdFusionOrmTraining.com/ >> >> -- >> You received this message because you are subscribed to the Google Groups >> "cfaussie" group. >> To post to this group, send email to cfaus...@googlegroups.com. >> To unsubscribe from this group, send email to >> cfaussie+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/cfaussie?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "cfaussie" group. > To post to this group, send email to cfaus...@googlegroups.com. > To unsubscribe from this group, send email to > cfaussie+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/cfaussie?hl=en. > _________________________________________________ Kai Koenig - Ventego Creative Ltd ph: +64 4 476 6781 - mob: +64 21 928 365 / +61 450 132 117 web: http://www.ventego-creative.co.nz blog: http://www.bloginblack.de twitter: http://www.twitter.com/agentK -- You received this message because you are subscribed to the Google Groups "cfaussie" group. To post to this group, send email to cfaus...@googlegroups.com. To unsubscribe from this group, send email to cfaussie+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cfaussie?hl=en.
