When upgrading from a previous version of Graylog you follow the previous used installation method (ex. from image or package) using the new version numbers.
The following Upgrade notes should be read carefully before you start the upgrade process. Breaking changes and dependency upgrades are documented in those upgrade notes.
You should always follow minor versions when updating across multiple versions to make sure necessary migrations are run correctly. The upgrade notes are always written coming from the stable release before.
Upgrading Graylog Originally Installed from Image¶
The Virtual Machine Appliance (OVA) and Amazon Web Services (AMI) installations of Graylog use the Omnibus package. The upgrade documentation using Omnibus is part of the graylog-ctl documentation.
Upgrading Graylog Originally Installed from Package¶
If the current installation was installed using a package manager (ex. yum, apt), update the repository package to the target version, and use the system tools to upgrade the package. For .rpm based systems this update guide and for .deb based systems this update guide should help.
Since Graylog 2.3 Elasticsearch 5.x is supported. This Graylog version supports Elasticsearch 2.x and 5.x. It is recommended to update Elasticsearch 2.x to the latest stable 5.x version, after you have Graylog 2.3 or later running. This Elasticsearch upgrade does not need to be made during the Graylog update.
When upgrading from Elasticsearch 2.x to Elasticsearch 5.x, make sure to read the upgrade guide provided by Elastic. The Graylog Elasticsearch configuration documentation contains information about the compatible Elasticsearch version. After the upgrade you must rotate the indices once manually.