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  • Latest Post - ‏2012-11-24T19:04:02Z by leiz
3 Posts

Pinned topic Question on WAS6.1 shared class cache

‏2012-11-23T16:23:01Z |

While investigating a server crash, I noticed that our 2 WAS 6.1 servers (under same WAS profile) have different and unusually large memory footprint (RHEL-Linux). Could anyone help with following 2 questions?

1. Both server's start args contain following values, are they supposed to use Same Instance of shared classes cache?

Xshareclasses:name=webspherev61_%g,groupAccess,nonFatal -Xscmx50M

2. See the extract below from "pmap" command below (note line with "**" at end) -- for WAS 6.1 the shared classes only include class files, is it normal for the cache to be over 1GB?

20032:   /opt/IBM/WebSphere/AppServer/java/bin/java -Declipse.security -Dwas.status.socket=55621 -Dosgi.install.area=/opt/IBM/WebSphere/AppServer -Dosgi.configuration.area=/opt/IBM/WebSphere/AppServer/profiles/AppSrv01 /configuration -Djava.awt.headless=

true -Dosgi.framework.extensions=com.ibm.cds -Xshareclasses:name=webspherev61_%g,groupAccess,nonFatal -Xscmx50M -Xbootclasspath/p: /opt/IBM/WebSphere/AppServer/java/jre/lib/ext/ibmorb.jar:/opt/IBM/WebSphere/AppServer /java/jre/lib/ext/ibmext.jar -classpath /opt/IBM/Web .... 00002aaaaf64c000    100K r-x--  /opt/IBM/WebSphere/AppServer/java/jre/bin/libj9shr23.so 00002aaaaf665000   1024K -----  /opt/IBM/WebSphere/AppServer/java/jre/bin/libj9shr23.so 00002aaaaf765000      8K rw---  /opt/IBM/WebSphere/AppServer/java/jre/bin/libj9shr23.so 00002aaaaf767000 1067280K rw---    [ anon ] ** 00002aaaf09ab000 468720K -----    [ anon ] 00002aab0d367000    892K rw---    [ anon ] 00002aab0d446000      4K -----    [ anon ]   19879:   /opt/IBM/WebSphere/AppServer/java/bin/java -Declipse.security -Dwas.status.socket=51141 -Dosgi.install.area=/opt/IBM/WebSphere/AppServer -Dosgi.configuration.area=/opt/IBM/WebSphere/AppServer/profiles/AppSrv01 /configuration -Djava.awt.headless=

true -Dosgi.framework.extensions=com.ibm.cds -Xshareclasses:name=webspherev61_%g,groupAccess,nonFatal -Xscmx50M -Xbootclasspath/p: /opt/IBM/WebSphere/AppServer/java/jre/lib/ext/ibmorb.jar:/opt/IBM/WebSphere/AppServer /java/jre/lib/ext/ibmext.jar -classpath /opt/IBM/Web 0000000000001000      4K rw---    [ anon ] 0000000000400000     56K r-x--  /opt/IBM/WebSphere/AppServer/java/jre/bin/java 000000000050e000      8K rw---  /opt/IBM/WebSphere/AppServer/java/jre/bin/java 0000000000510000      4K rw---    [ anon ] 000000000bc87000 118468K rw---    [ anon ] 0000000040000000      4K -----    [ anon ] .... 00002aaaaf765000      8K rw---  /opt/IBM/WebSphere/AppServer/java/jre/bin/libj9shr23.so 00002aaaaf767000 262144K rw---    [ anon ] 00002aaabf767000 1273856K -----    [ anon ]   ** 00002aab0d367000    892K rw---    [ anon ] ....

Updated on 2012-11-24T19:04:02Z at 2012-11-24T19:04:02Z by leiz
  • leiz
    3 Posts

    Re: Question on WAS6.1 shared class cache

    Just to add that we are also using WAS heap dump and java core files as well.
    The above post is mainly regarding whether the shared class cache processes (libj9shr23.so) is having other issues other than Heap exhaustion.