Pre-Upgrade Maintenance Tasks pre-upgrade-maintenance-tasks

Before beginning your upgrade, it is important to follow these maintenance tasks to ensure that the system is ready and can be rolled back should issues occur:

Ensure Sufficient Disk Space ensure-sufficient-disk-space

When executing the upgrade, in addition to the content and code upgrade activities, a repository migration must be performed. The migration creates a copy of the repository in the new Segment Tar format. As a result, you need enough disk space to retain a second, potentially larger, version of your repository.

Fully Back Up AEM fully-back-up-aem

AEM should be fully backed up before beginning the upgrade. Make sure to back up your repository, application installation, datastore, and Mongo instances if applicable. For more information on backing up and restoring an AEM instance, see Backup and Restore.

Back Up Changes to /etc backup-changes-etc

The upgrade process does a good job of maintaining and merging existing content and configurations from under the /apps and /libs paths in the repository. For changes made to the /etc path, including Context Hub configurations, it is often necessary to reapply these changes after the upgrade. While the upgrade makes a backup copy of any changes that it cannot merge under /var, Adobe recommends that you back up these changes manually before beginning the upgrade.

Generate The quickstart.properties File generate-quickstart-properties

When starting AEM from the jar file, a quickstart.properties file is generated under crx-quickstart/conf. If AEM has only been started with the start script in the past, this file is not present and the upgrade fails. Make sure to check for the existence of this file and restart AEM from the jar file if it is not present.

Configure Workflow and Audit Log Purging configure-wf-audit-purging

The WorkflowPurgeTask and com.day.cq.audit.impl.AuditLogMaintenanceTask tasks require separate OSGi configurations and cannot work without them. If they fail during pre-upgrade task execution, missing configurations is the most likely reason. Therefore, make sure to add OSGi configurations for these tasks or remove them altogether from the pre-upgrade optimization tasks list if you do not wish to run them. Documentation for configuring workflow purging tasks can be found at Administering Workflow Instances and audit log maintenance task configuration can be found at Audit Log Maintenance in AEM 6.

For workflow and audit log purging on CQ 5.6 and audit log purging on AEM 6.0, see Purge workflow and audit nodes.

Install, Configure, and Run The Pre-Upgrade Tasks install-configure-run-pre-upgrade-tasks

Because of the level of customization AEM allows, environments usually do not adhere to a uniform way of performing upgrades. As such, it makes creating a standardized procedure for upgrades a difficult process.

In previous versions, it was also difficult for AEM upgrades that were stopped or that have failed to safely resume. This issue led to situations in which restarting the full upgrade procedure was necessary or where defective upgrades were carried out without triggering any warnings.

To address these issues, Adobe has added several enhancements to the upgrade process, making it more resilient and user-friendly. Pre-upgrade maintenance tasks that before had to be performed manually are being optimized and automated. Also, post-upgrade reports have been added so that the process can be fully scrutinized in the hope that any issues are found more easily.

Pre-upgrade maintenance tasks are currently spread over various interfaces which are partially or entirely performed manually. The pre-upgrade maintenance optimization introduced in AEM 6.3 enables a unified way to trigger these tasks and be able to inspect their result on demand.

All tasks included in the pre-upgrade optimization step are compatible with all versions from AEM 6.0 onwards.

How to Set It Up how-to-set-it-up

In AEM 6.3 and later, the pre-upgrade maintenance optimization tasks come included in the quickstart jar.

How to Use It how-to-use-it

The PreUpgradeTasksMBean OSGI component comes preconfigured with a list of pre-upgrade maintenance tasks that can be run all at once. You can configure the tasks by following the below procedure:

The task list differs depending on the run mode that is being used to start the instance. Below is a description of the run mode that each maintenance task is designed for.

Default Configuration of the Pre-Upgrade Health Checks default-configuration-of-the-pre-upgrade-health-checks

The PreUpgradeTasksMBeanImpl OSGI component comes pre-configured with a list of pre-upgrade health check tags to execute when the runAllPreUpgradeHealthChecks method is called:

The list is editable. You can use the plus (+) and minus (-) buttons besides the tags to add more custom tags, or remove the default ones.

MBean Methods

The managed bean functionality can be accessed using the JMX Console.

You can access the MBeans by:

Below is a list of all the available methods that the PreUpgradeTasksMBeanImpl exposes:

Disable Custom Login Modules disable-custom-login-modules

The way custom LoginModules are configured for authentication at the repository level has fundamentally changed in Apache Oak.

In AEM versions that used CRX2 configuration was placed in the repository.xml file, while from AEM 6 onwards it is done in the Apache Felix JAAS Configuration Factory service via the Web Console.

Therefore, any existing configurations will have to be disabled and re-created for Apache Oak after the upgrade.

To disable the custom modules defined in the JAAS configuration of repository.xml, you must edit the configuration to use the default LoginModule, as in the following example:

<Security >
             ....
          <!--
                 Use LoginModule authenticating against repository itself
                 -->
                 <LoginModule class = "com.day.crx.core.CRXLoginModule" >
                     <param name = "anonymousId" value = "anonymous" />
                     <param name = "adminId" value ="admin" />
                     <param name = "disableNTLMAuth" value = "true" />
                     <param name = "tokenExpiration" value = "43200000" />
                     <!-- param name="trust_credentials_attribute" value="d5b9167e95dad6e7d3b5d6fa8df48af8"/
                -->
                 </LoginModule >
         </ Security>

Remove Updates From The /install Directory remove-updates-install-directory

Remove any service packs, feature packs, or hotfixes that were deployed through the crx-quickstart/install directory on the local file system. Doing so prevents the inadvertent installation of old hotfixes and service packs on top of the new AEM version after the update has completed.

Stop Any Cold Standby Instances stop-tarmk-coldstandby-instance

If using TarMK cold standby, stop any cold standby instances. Doing so guarantees an efficient way to come back online if there are issues in the upgrade. After the upgrade has completed successfully, the cold standby instances must be rebuilt from the upgraded primary instances.

Disable Custom Scheduled Jobs disable-custom-scheduled-jobs

Disable any OSGi scheduled jobs that are included in your application code.

Execute Offline Revision Cleanup execute-offline-revision-cleanup

If using TarMK, you should run Offline Revision Cleanup before upgrading. Doing so makes the repository migration step and subsequent upgrade tasks execute much faster and helps to ensure that Online Revision Cleanup can execute successfully after the upgrade has completed. For information on running Offline Revision Cleanup, see Performing Offline Revision Cleanup.

Execute Datastore Garbage Collection execute-datastore-garbage-collection

After running revision cleanup on CRX3 instances, you should run Datastore Garbage Collection to remove any unreferenced blobs in the data store. For instructions, see the documentation on Data Store Garbage Collection.

Upgrade the Database Schema If Needed upgrade-the-database-schema-if-needed

Usually, the underlying Apache Oak stack that AEM uses for persistence takes care of upgrading the database schema, if needed.

However, cases might arise when the schema cannot be upgraded automatically. Such cases are mostly high security environments where the database is running under a user with limited privileges. If such a situation occurs, AEM continues to use the old schema.

To prevent such a scenario from happening, upgrade the schema by doing the following:

Delete Users that Might Hinder the Upgrade delete-users-that-might-hinder-the-upgrade

There are exceptional cases when service users might end up in an older AEM version being improperly tagged as regular users.

If such a situation happens, the upgrade fails with a message like the following:

ERROR [Apache Sling Repository Startup Thread] com.adobe.granite.repository.impl.SlingRepositoryManager Exception in a SlingRepositoryInitializer, SlingRepository service registration aborted
java.lang.RuntimeException: Unable to create service user [communities-utility-reader]:java.lang.RuntimeException: Existing user communities-utility-reader is not a service user.

To work around this issue, make sure you do the following:

Rotate Log Files rotate-log-files

Adobe recommends archiving your current log files before beginning your upgrade. Doing so makes it easier to monitor and scan your log files during and after the upgrade to identify and resolve any issues that may occur.