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

Previous answers were insufficient in my case, probably because I'm on Debian 8, while they were referred to some previous distribution.

On Debian 8 modify the service script normally place in /usr/lib/systemd/system/elasticsearch.service, and add Environment=ES_HEAP_SIZE=8G just below the other "Environment=*" lines.

Now reload the service script with systemctl daemon-reload and restart the service. The job should be done!