Thread dump is not generating after running the High CPU script

Environment

• Red Hat JBoss Enterprise Application Platform (EAP)
  • 5.0.x

Issue

• After running the High CPU script as given in article How to identify high CPU utilization by Java threads on Linux/Solaris, thread dump is not generating . Errors are :

# ./high_cpu_linux_jstack.sh 28840
28840: Unable to open socket file: target process not responding or HotSpot VM not loaded
The -F option can be used when the target process is not responding

Resolution

Edit the init startup script jboss_init_redhat.sh under $JBOSS_HOME/bin directory and change the below in EAP 5.0.x

JBOSS_CONSOLE=${JBOSS_CONSOLE:-"/dev/null"}

to

JBOSS_CONSOLE=${JBOSS_CONSOLE:-"/opt/jboss/custom-path/console.log"}

or

JBOSS_CONSOLE=${JBOSS_CONSOLE:-"/$JBOSS_HOME/server/$JBOSS_CONF/console.out"}

Root Cause

• The console log was being directed to /dev/null which discards all data written to it.

Diagnostic Steps

• Check that the console log is not being directed to /dev/null

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