There are also some other GC options: http://java.sun.com/docs/hotspot/gc5.0/gc_tuning_5.html
The latest JVM's have a new GC that has much greater performance: http://java.sun.com/performance/reference/whitepapers/6_performance.html#2.2 http://java.sun.com/javase/6/docs/technotes/guides/vm/par-compaction-6.html http://java.sun.com/javase/6/webnotes/6u14.html Axton Grams The opinions, statements, and/or suggested courses of action expressed in this E-mail do not necessarily reflect those of BMC Software, Inc. My voluntary participation in this forum is not intended to convey a role as a spokesperson, liaison or public relations representative for BMC Software, Inc. On Wed, Jul 15, 2009 at 7:25 PM, Joe DeSouza<joe_rem...@yahoo.com> wrote: > ** > Hi Joe, > > This is done in the startup of Tomcat by including a startup paramter for > java: > -Xincgc > along with the startup memory and max memory that is defined. > > If you are on UNIX you will need to modify your startup.sh file where you > have these lines: > JAVA_OPTS="$JAVA_OPTS -Xms1536m"; export JAVA_OPTS > JAVA_OPTS="$JAVA_OPTS -Xmx2560m"; export JAVA_OPTS > to something like > > JAVA_OPTS="$JAVA_OPTS -Xms1536m"; export JAVA_OPTS > JAVA_OPTS="$JAVA_OPTS -Xmx2560m -Xincgc"; export JAVA_OPTS > > Restart Tomcat after that and then your process should look something like: > aradmin 3984 1 70 08:09 pts/1 00:00:11 > /apps/ar/jre1.6.0_13/bin/java -Xms1536m -Xmx2560m -Xincgc > -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager > -Djava.util.logging.config.file=/apps/ar/tomcat-5.5.25/conf/logging.properties > -Djava.endorsed.dirs=/apps/ar/tomcat-5.5.25/common/endorsed -classpath > :/apps/ar/tomcat-5.5.25/bin/bootstrap.jar:/apps/ar/tomcat-5.5.25/bin/commons-logging-api.jar > -Dcatalina.base=/apps/ar/tomcat-5.5.25 > -Dcatalina.home=/apps/ar/tomcat-5.5.25 > -Djava.io.tmpdir=/apps/ar/tomcat-5.5.25/temp > org.apache.catalina.startup.Bootstrap start > > Without the incremental garbage collection turned on your process would look > like: > aradmin 3531 1 0 Jun29 ? 00:04:10 > /apps/ar/jre1.6.0_13/bin/java -Xms1536m -Xmx2560m > -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager > -Djava.util.logging.config.file=/apps/ar/tomcat-5.5.25/conf/logging.properties > -Djava.endorsed.dirs=/apps/ar/tomcat-5.5.25/common/endorsed -classpath > :/apps/ar/tomcat-5.5.25/bin/bootstrap.jar:/apps/ar/tomcat-5.5.25/bin/commons-logging-api.jar > -Dcatalina.base=/apps/ar/tomcat-5.5.25 > -Dcatalina.home=/apps/ar/tomcat-5.5.25 > -Djava.io.tmpdir=/apps/ar/tomcat-5.5.25/temp > org.apache.catalina.startup.Bootstrap start > Are you on UNIX or Windows? The instructions I have given is for UNIX. If > you are on windows I think you need to modify your Java Options found in the > Java tab of the utility tomcat5w.exe > Hope this helps.. > > Joe > ________________________________ > From: remedydon <mrohinikanth2...@gmail.com> > To: arslist@ARSLIST.ORG > Sent: Wednesday, July 15, 2009 7:54:14 PM > Subject: Re: Apache Tomcat Memory Pool > > Hi Joe, > > > "Another useful tip would be to turn on incremental garbage collection. This > is always good to free up unused portions of memory that haven't been used > for a significant time interval." > > Where can I find this feature to turn it on ? > > Joe > > ________________________________ > From: "Begosh, Kevin" <kevin.beg...@lmco.com> > To: arslist@ARSLIST.ORG > Sent: Tuesday, February 3, 2009 3:14:40 PM > Subject: Re: Apache Tomcat Memory Pool > > ** > Yes this does help and I am on 7.1 as well so this would help out a lot. We > are having those exact issue with Tomcat crashing. > > Kevin Begosh, RSP > Tech Ops > Enterprise Business Services > 301-791-3540 Phone > 410-422-3623 Cell > kevin.beg...@lmco.com > > From:Action Request System discussion list(ARSList) > [mailto:arsl...@arslist.org] On Behalf Of Joe DeSouza > Sent: Tuesday, February 03, 2009 1:13 PM > To: arslist@ARSLIST.ORG > Subject: Re: Apache Tomcat Memory Pool > > ** > Thsi is more of a Tomcat setting than a 'BMC recommended' setting. > > The golden rule for sizing tomcat memory is to not use more than 65% to 70% > of the available free memory before the tomcat service is started. This > gives the server at least 30% to 35% headroom. > > With that in mind it is nice to have a max memory of at least around the 3 > GB mark where the usage of the servers is about average. > > Since you are using tomcat, if you are using Mid-Tier 7.1, I would recommend > to hop on the patch 006. In my experience here the earlier patches had a > memory issue, that addresses OutOfMemory errors that cause Tomcat to crash > which was addressed in Patch 006. Also the performance is way better as I > have noticed that it takes a relatively short time for the server to build > its cache after an initial restart on patch 006 (at least 5 to 10 times > faster) than it was on lets say Patch 003. I haven't tried patches in > between 003 and 006 > > Hope this helps.. > > Cheers > > Joe > > > ________________________________ > > From:"Begosh, Kevin" <kevin.beg...@lmco.com> > To: arslist@ARSLIST.ORG > Sent: Tuesday, February 3, 2009 12:53:46 PM > Subject: Apache Tomcat Memory Pool > > ** > Does anyone know what the BMC recommended or what the best settings are for > the Apache Tomcat memory pool for the Mid Tier. We are windows 2003 and we > have two mid tiers that are load balanced. > > Kevin Begosh, RSP > Tech Ops > Enterprise Business Services > 301-791-3540 Phone > 410-422-3623 Cell > kevin.beg...@lmco.com > _Platinum Sponsor: rmisoluti...@verizon.net ARSlist: "Where the Answers > Are"_ _______________________________________________________________________________ UNSUBSCRIBE or access ARSlist Archives at www.arslist.org Platinum Sponsor:rmisoluti...@verizon.net ARSlist: "Where the Answers Are"
