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  1. PUBLIC - Liferay Portal Community Edition
  2. LPS-49456

Classloader deadlock in ModuleFrameworkClassLoader



      Sometimes Master hangs at startup, see the attached thread dump for more details.

      As of Java SE 7, class loading related locks can have a finer granularity, that is, not the whole ClassLoader is locked, but the ClassLoader + <name of class begin loaded> instead.


      Steps to reproduce:

      That is a intermittent issue. You have to start the portal several times to reproduce.
      When it passes through this point (loading portal-ext), you haven't reproduced, you can interrupt the boot process and try again.

      INFO: Starting Servlet Engine: Apache Tomcat/7.0.34
      Sep 09, 2014 10:16:58 AM org.apache.catalina.startup.HostConfig deployDescriptor
      INFO: Deploying configuration descriptor /home/lcsontos/liferay/instances/lportal-trunk/tomcat-7.0.34/conf/Catalina/localhost/ROOT.xml
      Sep 09, 2014 10:17:10 AM org.apache.catalina.core.ApplicationContext log
      INFO: No Spring WebApplicationInitializer types detected on classpath
      Loading jar:file:/home/lcsontos/liferay/instances/lportal-trunk/tomcat-7.0.34/webapps/ROOT/WEB-INF/lib/portal-impl.jar!/system.properties
      Loading file:/home/lcsontos/liferay/instances/lportal-trunk/tomcat-7.0.34/webapps/ROOT/WEB-INF/classes/system-ext.properties
      Loading jar:file:/home/lcsontos/liferay/instances/lportal-trunk/tomcat-7.0.34/webapps/ROOT/WEB-INF/lib/portal-impl.jar!/portal.properties
      Loading file:/home/lcsontos/liferay/instances/lportal-trunk/portal-ext.properties

      If it got stuck at this point, take a thread dump and compare it to that one which is filed to the ticket. There should be such a part near to the end of the thread dump, which is saying that a deadlock has been detected.
      Found one Java-level deadlock:
      waiting to lock monitor 0x00007f1ad4048418 (object 0x00000007662e18b0, a com.liferay.portal.module.framework.ModuleFrameworkClassLoader),
      which is held by "localhost-startStop-1"
      waiting to lock monitor 0x00007f1ad4044fd8 (object 0x0000000780762ac0, a org.apache.catalina.loader.WebappClassLoader),
      which is held by "com.liferay.portal.log.bridge.internal.LogBridge@64c2fde"

      Actual Results:
      A deadlock has been detected.




            • Assignee:
              joyce.wang Joyce Wang
              laszlo.csontos Laszlo Csontos (Inactive)
              Participants of an Issue:
              Recent user:
              Esther Sanz
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              • Created:
                Days since last comment:
                5 years, 34 weeks, 3 days ago


                Version Package
                7.0.0 M3