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 >= 5 the documentation has changed, which means none of the above answers worked for me.

I tried changing ES_HEAP_SIZE in /etc/default/elasticsearch and in etc/init.d/elasticsearch, but when I ran ps aux | grep elasticsearch the output still showed:

/usr/bin/java -Xms2g -Xmx2g # aka 2G min and max ram

I had to make these changes in:

/etc/elasticsearch/jvm.options

# Xms represents the initial size of total heap space
# Xmx represents the maximum size of total heap space

-Xms1g 
-Xmx1g 
# the settings shipped with ES 5 were: -Xms2g
# the settings shipped with ES 5 were: -Xmx2g

Answer 2

For anyone looking to do this on Centos 7 or with another system running SystemD, you change it in

/etc/sysconfig/elasticsearch 

Uncomment the ES_HEAP_SIZE line, and set a value, eg:

# Heap Size (defaults to 256m min, 1g max)
ES_HEAP_SIZE=16g

(Ignore the comment about 1g max - that's the default)

Answer 3

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

Answer 4

• Elasticsearch will assign the entire heap specified in jvm.options via the Xms (minimum heap size) and Xmx (maximum heap size) settings.
  • -Xmx12g
  • -Xmx12g
• Set the minimum heap size (Xms) and maximum heap size (Xmx) to be equal to each other.

• Don’t set Xmx to above the cutoff that the JVM uses for compressed object pointers (compressed oops), the exact cutoff varies but is near 32 GB.

• It is also possible to set the heap size via an environment variable

  • ES_JAVA_OPTS="-Xms2g -Xmx2g" ./bin/elasticsearch
  • ES_JAVA_OPTS="-Xms4000m -Xmx4000m" ./bin/elasticsearch

Answer 5

In elasticsearch path home dir i.e. typically /usr/share/elasticsearch, There is a config file bin/elasticsearch.in.sh. Edit parameter ES_MIN_MEM, ES_MAX_MEM in this file to change -Xms2g, -Xmx4g respectively. And Please make sure you have restarted the node after this config change.