Upgrading to AEM 6.4

Last update: May 3, 2023

CREATED FOR:

  • Developer
CAUTION
AEM 6.4 has reached the end of extended support and this documentation is no longer updated. For further details, see our technical support periods. Find the supported versions here.

In this section, we cover upgrading an AEM installation to AEM 6.4:

For easier reference to the AEM instances involved in these procedures, the following terms are used throughout these articles:

  • The source instance is the AEM instance that you are upgrading from.
  • The target instance is the one that you are upgrading to.
NOTE
As part of the efforts to improve the reliability of upgrades, AEM 6.4 has undergone a comprehensive repository restructuring. For more information on how to align with the new structure, see Repository Restructuring in AEM 6.4

What Has Changed?

The following are major changes of note over the last several releases of AEM:

AEM 6.0 introduced the new Jackrabbit Oak repository. Persistence Managers were replaced by Micro Kernels. Starting from version 6.1, CRX2 is no longer supported. A migration tool called crx2oak needs to be run to migrate CRX2 repositories from 5.6.1 instances. For more information, see Using the CRX2OAK Migration Tool.

If Assets Insights is to be used and you are upgrading from a version older than AEM 6.2, assets must be migrated and have IDs generated through a JMX bean. In our internal tests, 125K assets on a TarMK environment were migrated in an hour, but your results may vary.

AEM 6.3 introduced a new format for the SegmentNodeStore, which is the basis of the TarMK implementation. If you are upgrading from a version older than AEM 6.3, this will require a repository migration as part of the upgrade, involving system downtime.

Adobe Engineering estimates this to be around 20 minutes. Note that reindexing will not be necessary. Additionally, a new version of the crx2oak tool has been released to work with the new repository format.

This migration is not required if upgrading from AEM 6.3 to AEM 6.4.

The pre-upgrade maintenance tasks have been optimized to support automation.

The crx2oak tool command line usage options have been changed to be automation friendly and support more upgrade paths.

The post-upgrade checks have also been made automation friendly.

Periodic garbage collection of revisions and data store garbage collection are now routine maintenance tasks that need to be performed periodically. With the introduction of AEM 6.3, Adobe supports and recommends Online Revision Cleanup. See Revision Cleanup for information on how to configure these tasks.

AEM 6.4 introduces the Pattern Detector for assessment of complexity of the upgrade as you start planning for the upgrade. 6.4 also has a strong focus on backward compatibility of features. Finally, best practices for sustainable upgrades are also added.

For more details about what else has changed in recent AEM versions, see the complete release notes: