Tomcat 7: How to set initial heap size correctly?

Question

I was trying to adjust initial heap size of a tomcat 7 (CentOS, java -version: 1.6.0_25-b06) instance by adding the following line to catalina.sh:

export CATALINA_OPTS="-Xms=512M -Xmx=1024M"

Starting up tomcat fails and logs the following message to catalina.out:

Invalid initial heap size: -Xms=512m
Could not create the Java virtual machine.

What is wrong with these options?

Answer 1

Go to "Tomcat Directory"/bin directory

if Linux then create setenv.sh else if Windows then create setenv.bat

content of setenv.* file :

export CATALINA_OPTS="$CATALINA_OPTS -Xms512m"
export CATALINA_OPTS="$CATALINA_OPTS -Xmx8192m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:MaxPermSize=256m"

after this restart tomcat with new params.

explanation and full information is here

http://crunchify.com/how-to-change-jvm-heap-setting-xms-xmx-of-tomcat/

Answer 2

It works even without using 'export' keyword. This is what i have in my setenv.sh (/usr/share/tomcat7/bin/setenv.sh) and it works.

OS : 14.04.1-Ubuntu Server version: Apache Tomcat/7.0.52 (Ubuntu) Server built: Jun 30 2016 01:59:37 Server number: 7.0.52.0

JAVA_OPTS="-Dorg.apache.catalina.security.SecurityListener.UMASK=`umask` -server -Xms6G -Xmx6G -Xmn1400m -XX:HeapDumpPath=/Some/logs/ -XX:+HeapDumpOnOutOfMemoryError -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:SurvivorRatio=8 -XX:+UseCompressedOops -Dcom.sun.management.jmxremote.port=8181 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false"
JAVA_OPTS="$JAVA_OPTS -Dserver.name=$HOSTNAME"

Answer 3

You might no need to having export, just add this line in catalina.sh :

CATALINA_OPTS="-Xms512M -Xmx1024M"

Answer 4

Use following command to increase java heap size for tomcat7 (linux distributions) correctly:

echo 'export CATALINA_OPTS="-Xms512M -Xmx1024M"' > /usr/share/tomcat7/bin/setenv.sh

Answer 5

You must not use =. Simply use this:

export CATALINA_OPTS="-Xms512M -Xmx1024M"

Answer 6

Just came across this and I've implemented Nathan's solution:

add the line (changing the values as required):

export JAVA_OPTS="-Xms512M -Xmx1024M"

to /usr/share/tomcat7/bin/setenv.sh

If that file doesn't exists then create it and

chown root:root it
chmod 755 it

And then restart tomcat and check it with

ps aux | grep logging

Which should just pick up the instance and show the java parms