How to change Elasticsearch max memory size

Question

I have an Apache server with a default configuration of Elasticsearch and everything works perfectly, except that the default configuration has a max size of 1GB.

I

Answer 1

If you installed ES using the RPM/DEB packages as provided (as you seem to have), you can adjust this by editing the init script (/etc/init.d/elasticsearch on RHEL/CentOS). If you have a look in the file you'll see a block with the following:

export ES_HEAP_SIZE
export ES_HEAP_NEWSIZE
export ES_DIRECT_SIZE
export ES_JAVA_OPTS
export JAVA_HOME

To adjust the size, simply change the ES_HEAP_SIZE line to the following:

export ES_HEAP_SIZE=xM/xG

(where x is the number of MB/GB of RAM that you would like to allocate)

Example:

export ES_HEAP_SIZE=1G

Would allocate 1GB.

Once you have edited the script, save and exit, then restart the service. You can check if it has been correctly set by running the following:

ps aux | grep elasticsearch

And checking for the -Xms and -Xmx flags in the java process that returns:

/usr/bin/java -Xms1G -Xmx1G

Hope this helps :)