Overview

This article describes how to request an upgrade of an individual Content Hub environment from versions earlier than 4.2 to a later version.

Note that upgrade requests for environments on version 4.2 or later are no longer supported. More information on how environments starting from version 4.2 get upgraded can be found in the Upgrading Content Hub environment starting from version 4.2 section below.

Required actions

Requesting an upgrade can be done by creating a service request from the Sitecore Support Portal.

The following information should be specified by the requestor (Customer or Partner):

• the Customer’s name
• the environment that needs upgrading
• the target Content Hub version
• the preferred execution timeslot

Requestors will also have to acknowledge that they have read, understood, and planned for mitigation of any breaking changes that might occur due to the upgrade.

Content Hub Versions

Content Hub versions earlier than 4.2 are identified with 3 digits as follows:

X.Y.Z, where X - the major version, Y - the minor version, Z - the patch version.

Notes:

• Major and minor versions are feature releases, while the patch releases only contain bug fixes.
• A requestor can request an upgrade to a specific feature or patch release.
• Sitecore automatically upgrades the environment to the latest X.Y.Z patch release if only the feature release X.Y is specified.

Downtime during the upgrade from versions earlier than 4.2

Feature releases (X.Y) require some downtime, while patch releases (X.Y.Z) for Content Hub 4.x onwards do not.  The amount of downtime needed depends on the source version of the environment and the size of the database.

The below table gives an indication only of the required downtimes:

		Upgrade type
		Feature upgrade (X or X.Y) with more than 50 GB Redis database	Feature upgrade (X or X.Y) with less than 50 GB Redis database	Patch upgrade (X.Y.Z)
Current Content Hub version	Earlier than 3.3	Analysis is required to estimate downtime	Analysis is required to estimate downtime	Not applicable
	Earlier than 4.0	Analysis is required to estimate downtime	16 hours	4 hours
	4.0 or later	Analysis is required to estimate downtime	4 hours per upgrade step (for example, 4.0- 4.1- 4.2 takes 2 times 4 hours = 8 hours)	No downtime needed

Note: Public links remain available during upgrades, even for upgrades that require downtime.

Breaking changes

While breaking changes are avoided as much as possible, a requestor should be familiar with the breaking changes documented in Content Hub Release Notes before requesting a feature upgrade: https://doc.sitecore.com/ch/en/users/42/content-hub/digital-assets.html

The requestor is explicitly expected to plan for mitigation of these breaking changes.

Rollbacks

When encountering unexpected difficulties during the upgrade, Sitecore always tries to complete the upgrade first.  Only as a last resort, Sitecore executes a rollback making use of the following measures:

• A manual backup of the Redis DB is taken before each upgrade.
• If the upgrade fails, there are no changes to the application, and it stays at the old version without any impact.
• In case of issues after the upgrade, the Redis DB backup can be used to restore the application to the old state.

Upgrading Content Hub environment starting from version 4.2

Sitecore is releasing maintenance in an automated way for Content Hub environments on version 4.2 or later. 

• Standard releases will happen regularly across all environments and require zero downtime.
• Any releases with "breaking changes" will be communicated at least 30 calendar days in advance. Releases with "breaking changes" will be applied to non-production environments first and to production environments at least 14 calendar days later. More details can be found in the Sitecore SaaS Products Service Level Agreement (SLA) here: https://www.sitecore.com/legal/sla/saas

As a result of this, individual upgrade requests for environments on version 4.2 or later are no longer supported.