2 Replies Latest reply on Feb 14, 2007 4:13 AM by Piero Ottuzzi

    High CPU usage in Weblogic 8.1

    Piero Ottuzzi Newbie

      Hi there,

      I'm evaluating Treecache as cluster cache in our environment: we are running a weblogic8.1SP2 cluster deployed on Solaris 5.9 (aka Solaris 9) with SUN JDK 1.4.1_02.

      Here is the configuration I'm using:

      <?xml version="1.0" encoding="UTF-8"?>
      <server>
      
       <classpath codebase="./lib" archives="jboss-cache.jar, jgroups.jar"/>
      
      
       <mbean code="org.jboss.cache.TreeCache"
       name="jboss.cache:service=TreeCache">
      
       <attribute name="IsolationLevel">REPEATABLE_READ</attribute>
       <attribute name="CacheMode">REPL_ASYNC</attribute>
       <attribute name="UseReplQueue">false</attribute>
       <attribute name="ReplQueueInterval">0</attribute>
       <attribute name="ReplQueueMaxElements">0</attribute>
       <attribute name="ClusterName">TreeCache-RA-Cluster</attribute>
       <attribute name="ClusterConfig">
       <config>
       <UDP mcast_addr="228.1.2.3" mcast_port="48866"
       ip_ttl="64" ip_mcast="true"
       mcast_send_buf_size="150000" mcast_recv_buf_size="80000"
       ucast_send_buf_size="150000" ucast_recv_buf_size="80000"
       loopback="false"/>
       <PING timeout="2000" num_initial_members="3"
       up_thread="false" down_thread="false"/>
       <MERGE2 min_interval="10000" max_interval="20000"/>
       <FD_SOCK/>
       <VERIFY_SUSPECT timeout="1500"
       up_thread="false" down_thread="false"/>
       <pbcast.NAKACK gc_lag="50" retransmit_timeout="600,1200,2400,4800"
       max_xmit_size="8192" up_thread="false" down_thread="false"/>
       <UNICAST timeout="600,1200,2400" down_thread="false"/>
       <pbcast.STABLE desired_avg_gossip="20000"
       up_thread="false" down_thread="false"/>
       <pbcast.GMS join_timeout="5000" join_retry_timeout="2000"
       shun="true" print_local_addr="true"/>
       <FC max_credits="2000000" down_thread="false" up_thread="false"
       min_threshold="0.20"/>
       <FRAG frag_size="8192" down_thread="false" up_thread="true"/>
       <pbcast.STATE_TRANSFER up_thread="true" down_thread="true"/>
       </config>
       </attribute>
      
       <attribute name="FetchInMemoryState">true</attribute>
       <attribute name="InitialStateRetrievalTimeout">20000</attribute>
       <attribute name="SyncReplTimeout">20000</attribute>
       <attribute name="LockAcquisitionTimeout">15000</attribute>
       <attribute name="EvictionPolicyClass">org.jboss.cache.eviction.LRUPolicy</attribute>
       <attribute name="EvictionPolicyConfig">
       <config>
       <attribute name="wakeUpIntervalSeconds">30</attribute><!-- 30 SECONDS -->
       <!-- Cache wide default -->
       <region name="/_default_">
       <attribute name="maxNodes">10000</attribute>
       <attribute name="timeToLiveSeconds">1800</attribute><!-- 30 MINUTES -->
       <attribute name="maxAgeSeconds">1800</attribute><!-- 30 MINUTES -->
       </region>
       <region name="/USER/">
       <attribute name="maxNodes">1000</attribute>
       <attribute name="timeToLiveSeconds">900</attribute><!-- 15 MINUTES -->
       <attribute name="maxAgeSeconds">900</attribute><!-- 15 MINUTES -->
       </region>
       </config>
       </attribute>
       <attribute name="UseRegionBasedMarshalling">true</attribute>
      
       </mbean>
      
       </server>


      During tests I see a very HIGH CPU usage caused by TreeCache: without cache I see a CPU usage of about 10%, with TreeCache I can see even 20% CPU usage.
      I made more tests to better understand the problem and I found that the simple cache initialization (I commented out all put/get/remove methods accessing Treecache and I simply initialized cache with the above XML) is enough to see the abnormal CPU usage: what is happening there?

      Any help would be greatly appreciated.
      Thanks
      Bye
      Piero