eXo Platform aims at providing a transparent upgrade experience so that the upgrade to a newer version is seamless for an administrator.

As eXo makes changes between versions, it is sometimes required to run some routines that will alter data. eXo Platform comes with a service dedicated to it - called the Upgrade Service. This generic framework can detect a version change and identify which upgrade routines to be executed.

Since the framework leverages the eXo plugins mechanism, eXo refers to these routines as "upgrade plugins". At startup, eXo Platform will load and execute the upgrade plugins identified by the Upgrade Service.

This chapter outlines requirements before the upgrade and helps you get familiar with the upgrade process between versions of eXo Platform 4 via the following topics:

Also, this chapter contains links to sections that you need before starting an upgrade.