Setting Elasticsearch Heap Size in Windows

Elasticsearch has an option to configure the memory which is used by elasticsearch java process.

The memory can be configured using various Environmental Variables.

The default Heap Size of an elasticsearch process in 1gb. The ES_HEAP_SIZE environment variable allows setting the heap memory that will be allocated to elasticsearch java process.

We can set Environment Variable as follows

ES_HEAP_SIZE

4g

We can check allocated memory using service manager of elasticsearch as follows

cmd

manager

And another option is to lock the process address space into RAM, preventing any Elasticsearch memory from being swapped out by configuring as follows in Elasticsearch configuration file (config/elasticsearch.yml)

bootstrap.mlockall: true

We can check whether settings are applied to the nodes or not by using any one of the following commands

curl http://localhost:9200/_nodes/process?pretty
GET /_nodes/process?pretty

If we receive mlockall is false by running above commands, then it means that the mlockall request has failed.

Explore data using Elastic 🙂

Note:

Note that the environment configuration options available during the installation are copied and will be used during the service life cycle. This means any changes made to them after the installation will not be picked up unless the service is reinstalled.

Elasticsearch is having some minor issue in locking the memory(using Virtual lock) in Windows OS; there is already an open issue raised in Github repository of elastic.