Installing OpenSearch

This section details how to install OpenSearch on your host, including which operating systems are compatible with OpenSearch, which ports to open, and which important settings to configure on your host.

Operating system compatibility

We recommend installing OpenSearch on Red Hat Enterprise Linux (RHEL) or Debian-based Linux distributions that use systemd, such as CentOS, Amazon Linux 2, or Ubuntu Long-Term Support (LTS). OpenSearch should work on most Linux distributions, but we only test a handful. We recommend RHEL 7 or 8, CentOS 7 or 8, Amazon Linux 2, or Ubuntu 16.04, 18.04, or 20.04 for any version of OpenSearch. OpenSearch also supports Windows Server 2019.

Avoid using a network file system for node storage in a production workflow. Using a network file system for node storage can cause performance issues in your cluster due to factors such as network conditions (like latency or limited throughput) or read/write speeds. You should use solid-state drives (SSDs) installed on the host for node storage where possible.

Java compatibility

The OpenSearch distribution for Linux ships with a compatible Adoptium JDK version of Java in the jdk directory. To find the JDK version, run ./jdk/bin/java -version. For example, the OpenSearch 1.0.0 tarball ships with Java 15.0.1+9 (non-LTS), OpenSearch 1.3.0 ships with Java 11.0.14.1+1 (LTS), and OpenSearch 2.0.0 ships with Java 17.0.2+8 (LTS). OpenSearch is tested with all compatible Java versions.

OpenSearch VersionCompatible Java VersionsBundled Java Version
1.0 - 1.2.x11, 1515.0.1+9
1.3.x8, 11, 1411.0.14.1+1
2.0.011, 1717.0.2+8

To use a different Java installation, set the OPENSEARCH_JAVA_HOME or JAVA_HOME environment variable to the Java install location. For example:

  1. export OPENSEARCH_JAVA_HOME=/path/to/opensearch-2.5.0/jdk

Network requirements

The following ports need to be open for OpenSearch components.

Port numberOpenSearch component
443OpenSearch Dashboards in AWS OpenSearch Service with encryption in transit (TLS)
5601OpenSearch Dashboards
9200OpenSearch REST API
9250Cross-cluster search
9300Node communication and transport
9600Performance Analyzer

Important settings

For production workloads, make sure the Linux setting vm.max_map_count is set to at least 262144. Even if you use the Docker image, set this value on the host machine. To check the current value, run this command:

  1. cat /proc/sys/vm/max_map_count

To increase the value, add the following line to /etc/sysctl.conf:

  1. vm.max_map_count=262144

Then run sudo sysctl -p to reload.

The sample docker-compose.yml file also contains several key settings:

  • bootstrap.memory_lock=true

    Disables swapping (along with memlock). Swapping can dramatically decrease performance and stability, so you should ensure it is disabled on production clusters.

  • OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m

    Sets the size of the Java heap (we recommend half of system RAM).

  • nofile 65536

    Sets a limit of 65536 open files for the OpenSearch user.

  • port 9600

    Allows you to access Performance Analyzer on port 9600.

Do not declare the same JVM options in multiple locations because it can result in unexpected behavior or a failure of the OpenSearch service to start. If you declare JVM options using an environment variable, such as OPENSEARCH_JAVA_OPTS=-Xms3g -Xmx3g, then you should comment out any references to that JVM option in config/jvm.options. Conversely, if you define JVM options in config/jvm.options, then you should not define those JVM options using environment variables.