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 don't have such a large number of documents to store in Elasticsearch, so I want to reduce the memory.

I have seen that I have to change the -Xmx parameter in the Java configuration, but I don't know how.

I have seen I can execute this:

bin/ElasticSearch -Xmx=2G -Xms=2G

But when I have to restart Elasticsearch this will be lost.

Is it possible to change max memory usage when Elasticsearch is installed as a service?

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

Updated on Nov 24, 2016: Elasticsearch 5 apparently has changed the way to configure the JVM. See this answer here. The answer below still applies to versions < 5.

tirdadc, thank you for pointing this out in your comment below.

---

I have a pastebin page that I share with others when wondering about memory and ES. It's worked OK for me: http://pastebin.com/mNUGQCLY. I'll paste the contents here as well:

References:

https://github.com/grigorescu/Brownian/wiki/ElasticSearch-Configuration http://www.elasticsearch.org/guide/reference/setup/installation/

Edit the following files to modify memory and file number limits. These instructions assume Ubuntu 10.04, may work on later versions and other distributions/OSes. (Edit: This works for Ubuntu 14.04 as well.)

/etc/security/limits.conf:

elasticsearch - nofile 65535
elasticsearch - memlock unlimited

/etc/default/elasticsearch (on CentOS/RH: /etc/sysconfig/elasticsearch ):

ES_HEAP_SIZE=512m
MAX_OPEN_FILES=65535
MAX_LOCKED_MEMORY=unlimited

/etc/elasticsearch/elasticsearch.yml:

bootstrap.mlockall: true

Answer 3

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 4

Instructions for ubuntu 14.04:

sudo vim /etc/init.d/elasticsearch

Set

ES_HEAP_SIZE=512m

then in:

sudo vim /etc/elasticsearch/elasticsearch.yml

Set:

bootstrap.memory_lock: true

There are comments in the files for more info

Answer 5

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!

Answer 6

If you use the service wrapper provided in Elasticsearch's Github repository, found at https://github.com/elasticsearch/elasticsearch-servicewrapper, then the conf file at elasticsearch-servicewrapper / service / elasticsearch.conf controls memory settings. At the top of elasticsearch.conf is a parameter:

set.default.ES_HEAP_SIZE=1024

Just reduce this parameter, say to "set.default.ES_HEAP_SIZE=512", to reduce Elasticsearch's allotted memory.

Note that if you use the elasticsearch-wrapper, the ES_HEAP_SIZE provided in elasticsearch.conf OVERRIDES ALL OTHER SETTINGS. This took me a bit to figure out, since from the documentation, it seemed that heap memory could be set from elasticsearch.yml.

If your service wrapper settings are set somewhere else, such as at /etc/default/elasticsearch as in James's example, then set the ES_HEAP_SIZE there.

Answer 7

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 :)

Answer 8

• 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 9

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.

Answer 10

File path to change heap size /etc/elasticsearch/jvm.options

If you are using nano then do sudo nano /etc/elasticsearch/jvm.options and update -Xms and -Xmx accordingly.

(You can use any file editor to edit it)

Answer 11

Create a new file with the extension .options inside /etc/elasticsearch/jvm.options.d and put the options there. For example:

sudo nano /etc/elasticsearch/jvm.options.d/custom.options

and put the content there:

# JVM Heap Size - see /etc/elasticsearch/jvm.options
-Xms2g
-Xmx2g

It will set the maximum heap size to 2GB. Don't forget to restart elasticsearch:

sudo systemctl restart elasticsearch

Now you can check the logs:

sudo cat /var/log/elasticsearch/elasticsearch.log | grep "heap size"

You'll see something like so:

… heap size [2gb], compressed ordinary object pointers [true]

Doc

Answer 12

If you use windows server, you can change Environment Variable, restart server to apply new Environment Value and start Elastic Service. More detail in Install Elastic in Windows Server

Answer 13

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