Introduction To Upgrading | Upgrading Elasticsearch

Overview

Upgrading Elasticsearch is an essential task to ensure that you are benefiting from the latest features, performance improvements, and security patches. This tutorial will guide you through the process of upgrading Elasticsearch from start to finish with detailed explanations and examples.

Preparation

Before proceeding with the upgrade, it is crucial to take the following steps to prepare your environment:

Back up your data: Always ensure that you have a recent backup of your data.
Read the release notes: Check the release notes for your target version for any breaking changes or important information.
Test the upgrade in a staging environment: It is advisable to test the upgrade process in a staging environment identical to your production setup.

Step-by-Step Upgrade Process

Step 1: Check Compatibility

Before upgrading, ensure that your current version is compatible with the target version. Elasticsearch provides a deprecation log to help you identify any deprecated features you are using.

Example of checking the deprecation log:

GET /_cat/indices?v

Step 2: Set Up Repositories

Set up the appropriate repositories for your operating system to download the new version of Elasticsearch. For example, on a Debian-based system, update the source list:

sudo apt-get update

Step 3: Upgrade Elasticsearch

Using the package manager for your operating system, upgrade Elasticsearch. On a Debian-based system, you can use the following command:

sudo apt-get install elasticsearch

Step 4: Restart and Verify

After the installation, restart the Elasticsearch service and verify that the upgrade was successful:

sudo systemctl restart elasticsearch

curl -X GET "localhost:9200"

{ "name" : "node-1", "cluster_name" : "elasticsearch", "cluster_uuid" : "abc123", "version" : { "number" : "7.10.0", "build_flavor" : "default", "build_type" : "deb", "build_hash" : "abc123", "build_date" : "2020-11-11T14:33:48.223973Z", "build_snapshot" : false, "lucene_version" : "8.7.0" }, "tagline" : "You Know, for Search" }

Post-Upgrade Tasks

After a successful upgrade, perform the following tasks:

Check the cluster health: Use the GET /_cluster/health API to ensure that the cluster status is green.
Re-enable index allocation: If you disabled it before the upgrade, re-enable index allocation.
Review and address any deprecation warnings: Check the logs for any deprecation warnings and address them.

Conclusion

Upgrading Elasticsearch is a critical task to maintain the health and performance of your search infrastructure. By following the steps outlined in this tutorial, you can ensure a smooth and successful upgrade process. Always remember to back up your data, test in a staging environment, and carefully follow the upgrade steps.

Introduction to Upgrading Elasticsearch