From: Ameer Mawia <ameer.ma...@gmail.com> To: Tomcat Users List <users@tomcat.apache.org> Date: 04/17/2015 06:29 PM Subject: Re: GC Issue on Tomcat6
http://ca.linkedin.com/in/ameermawia Toronto, ON Phone:647-262-4380 On Fri, Apr 17, 2015 at 8:47 AM, David kerber <dcker...@verizon.net> wrote: > On 4/17/2015 8:32 AM, Subhro Paul wrote: > >> Hi Team, >> >> For our client website we have two Tomcat servers. Both servers are having >> same configuration which is 16GB RAM, 8CPUS and Linux 6.5 OS. Tomcat 6 and >> JAVA 6 are installed in both systems. >> >> Yesterday, using Jconsole we observed that frequency of GC on one server >> was very high which was 5 GC hit per Minute and on other server it was 1 >> GC hit per 3 Minutes. But today we observed that on both of the servers GC >> frequency is same. >> >> Garbage Collection in Oracle Hot spot JVM takes place in generational manner. GC on young generation is invoked much more frequently, while Full GC is invoked once in a while. In any case, frequency is much higher than what you have mentioned. I'm not sure which GC(Young/Full) you are talking about? What pattern of GC you have earlier observed? > Is this a know secnario or the server is facing any issue? >> > > GC issue has nothing to do with Tomcat per say. It is the memory footprint of your application which will dictate GC behavior. In any case, if your application is facing some memory bottle-neck, it is better to pay attention on the percentage your JVM is spending in GCing your application. If that percentage is very high, say ~90%, that means your application is facing sever memory constrain, your application is almost stalled as JVM has been trying very high to recover some space. Most probably in that case, your JVM will die throwing OOM error in sometime. > It was probably just receiving more traffic and/or doing more work of some > other kind. > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > > Dear Ameer, I am talking about Young GC which is "PS Scavenge" for both of the servers. Full GC was Running 1/Hour. Can you please assist how to check the % of memory utilization by GC through JConsole or any other process. Thanks & Regards, Subhro Paul =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you
