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

In elasticsearch 2.x :

vi /etc/sysconfig/elasticsearch 

Go to the block of code

# Heap size defaults to 256m min, 1g max
# Set ES_HEAP_SIZE to 50% of available RAM, but no more than 31g
#ES_HEAP_SIZE=2g

Uncomment last line like

ES_HEAP_SIZE=2g