[LINUX] Set Tomcat to restart automatically when it raises an OutOfMemoryError

Memory leaks occur. However, I would like to avoid being notified that the site has gone down during a long vacation, so I investigated the method.

1: Prepare a batch file that you want to execute automatically when OutOfMemoryError occurs.

Example: Create a file restartTomcat.sh like ↓ and place it in an appropriate location (/ usr / local / tomcat / bin, etc.).

• Add execute permission with "chmod + x restartTomcat.sh" etc.

restartTomcat.sh

#!/bin/bash

#Restart tomcat (example) If there is a command you want to execute other than restart, write it together. Like skipping emails.
systemctl restart tomcat.service

2: Add XX: OnOutOfMemoryError to the jvm option of Tomcat.

Add the following option to the environment variable CATALINA_OPTS to specify the command to execute on OutOfMemoryError.

• -XX:OnOutOfMemoryError

One way to specify the tomcat jvm option is If you put a file called "setenv.sh" in / usr / local / tomcat / bin, it will be read from catalina.sh when Tomcat starts.

Example:

setenv.sh

export CATALINA_OPTS="$CATALINA_OPTS -XX:OnOutOfMemoryError=\"/usr/local/tomcat/bin/restartTomcat.sh\""

This will run restartTomcat.sh on OutOfMemoryError.

3: HeapDump is also output.

If you also want to output HeapDump, add the following two options to the environment variable CATALINA_OPTS.

--- XX: + HeapDumpOnOutOfMemoryError (HeapDump is output at the time of OutOfMemoryError.) --- XX: HeapDumpPath (Specify the output destination of HeapDump above.)

Example:

setenv.sh

export CATALINA_OPTS="$CATALINA_OPTS -XX:+HeapDumpOnOutOfMemoryError"
export CATALINA_OPTS="$CATALINA_OPTS -XX:HeapDumpPath=/usr/local/tomcat/logs"
export CATALINA_OPTS="$CATALINA_OPTS -XX:OnOutOfMemoryError=\"/usr/local/tomcat/bin/restartTomcat.sh\""

• However, it is unclear whether HeapDump is completed before Tomcat is restarted, so If you want to output HeapDump surely, instead of HeapDumpOnOutOfMemoryError, you should dump from restartTomcat.sh so that Tomcat does not restart before outputting the dump ...