title: Weblogic to tomcat migration performance issue
body: <p>We successfully migrated our web applications from Weblogic to tomcat 7.
  The web application is built using.</p>
  
  <ol>
  <li>Spring</li>
  <li>Jsp</li>
  <li>Uses the weblogic Datasources</li>
  </ol>
  
  <p>When we migrated to Tomcat we started using DBCP. But thinking to change to Tomcat JDBC Connection pooling. Please suggest would this be helpful.</p>
  
  <p>The application has to perform some heavy transactions on the server side. </p>
  
  <p>But the tomcat fails to deliver the performance and stability which we get in weblogic.</p>
  
  <p>There are too many GC thread running on tomcat and this makes the application to hang. Almost 2/7 of the total time is spent on GC.</p>
  
  <p>Here is the JVM initialization string</p>
  
  <pre><code>JAVA_OPTS="$JAVA_OPTS -server -Xms120G -Xmx120G -Xmn60G -XX:PermSize=512m -XX:MaxPermSize=512m -XX:MaxNewSize=40G -XX:NewSize=40G -Xloggc:$CATALINA_HOME/logs/gc.log -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+DisableExplicitGC -XX:+CMSClassUnloadingEnabled -XX:+UseLargePages -XX:LargePageSizeInBytes=1200m"
  </code></pre>
  
  <p>Please help me to tune the tomcat for better performance and stability.</p>