-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Donald,
On 8/11/2010 12:15 PM, Donald Armstrong wrote: > We have recently deployed tomcat-6.0.28 in our organization and are > noticing every hour, a Full GC is occurring. The same application, > same JVM, same JVM args, just a new tomcat release. > > I have addressed the issue by adjusting the server.xml and disabling > gcDaemonProtection. Why? > Ideas on what is causing the Full GC and why every hour? There is no javadoc for this class which is unfortunate, but the documentation in http://tomcat.apache.org/tomcat-6.0-doc/config/listeners.html is likely where you found this configuration option. Here's what it says about gcDaemonProtection: " Enables protection so that calls to sun.misc.GC.requestLatency(long) triggered by a web application do not result in a memory leak. Use of RMI is likely to trigger a call to this method. A side effect of enabling this protection is the creation of a thread named "GC Daemon". The protection is uses reflection to access internal Sun classes and may generate errors on startup on non-Sun JVMs. The default is true. " Looking at the code for JreMemoryLeakPreventionListener, no threads are fired from that code. The code in there calls the static method sun.misc.GC.requestLatency(3600000l) - that's one hour, if the argument is in ms. I'm having trouble following the decompiled code, but I can't find anywhere that a Thread is actually started. Have you tried to take a thread dump to see what threads are running? Presumably, you ought to see something interesting in there. Are you able to run a profiler against the process to see where the thread is created? - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkxi3w4ACgkQ9CaO5/Lv0PAYBQCfe7+POwLPcW6p9QQyWlLbSspZ Z+EAn1H1FrU2QQ40fUiywug7Ohz2fpP7 =GC7n -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
