[[setup-upgrade]]
== Upgrading

[IMPORTANT]
===========================================
Before upgrading Elasticsearch:

* Consult the <<breaking-changes,breaking changes>> docs.
* Test upgrades in a dev environment before upgrading your production cluster.
* Always <<modules-snapshots,back up your data>> before upgrading.
  You **cannot roll back** to an earlier version unless you have a backup of your data.
* If you are using custom plugins, check that a compatible version is available.
===========================================

Elasticsearch can usually be upgraded using a rolling upgrade process,
resulting in no interruption of service.  This section details how to perform
both rolling upgrades and upgrades with full cluster restarts.

To determine whether a rolling upgrade is supported for your release, please
consult this table:

[cols="1<m,1<m,3",options="header",]
|=======================================================================
|Upgrade From   |Upgrade To     |Supported Upgrade Type
|2.x            |2.y            |<<rolling-upgrades,Rolling upgrade>> (where `y > x`)
|5.x            |5.y            |<<rolling-upgrades,Rolling upgrade>> (where `y > x`)
|2.x            |5.x            |<<restart-upgrade,Full cluster restart>>
|5.0.0-alpha1   |5.y            |<<restart-upgrade,Full cluster restart>>
|5.0.0-alpha2   |5.y            |<<restart-upgrade,Full cluster restart>>
|5.0.0-beta1    |5.y            |<<restart-upgrade,Full cluster restart>>
|=======================================================================

include::rolling_upgrade.asciidoc[]

include::cluster_restart.asciidoc[]
