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The "ZooKeeper/Troubleshooting" page has been changed by PatrickHunt. http://wiki.apache.org/hadoop/ZooKeeper/Troubleshooting?action=diff&rev1=10&rev2=11 -------------------------------------------------- The Java GC can cause [[https://issues.apache.org/jira/browse/HBASE-1316|starvation of the Java threads]] in the VM. This manifests itself as client disconnects and session expirations due to starvation of the heartbeat thread. The GC runs, locking out all Java threads from running. + You can get an idea of what's happening wrt GC in your client/server VMs by using the following options when starting the JVM: + + -Xloggc:gc.log -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCApplicationConcurrentTime -XX:+PrintGC -XX:+PrintGCTimeStamps -XX:+PrintGCDetails + + Additionally you can use 'jstat' on a running jvm to gain more insight into realtime GC activity, see: http://java.sun.com/j2se/1.5.0/docs/tooldocs/share/jstat.html + This issue can be resolved in a few ways: First look at using one of the alternative GCs, in particular [[http://developer.amd.com/documentation/articles/pages/4EasyWaystodoJavaGarbageCollectionTuning.aspx|low latency GC]]:
