Rollout Conflicts msm-rollout-conflicts
Conflicts can occur if new pages with the same page name are created in both the blueprint branch and a dependent Live Copy branch. Such conflicts must be handled and resolved on rollout.
Conflict Handling conflict-handling
When conflicting pages do exist (in the blueprint and Live Copy branches), MSM lets you define how (or even if) they should be handled.
To ensure that the rollout is not blocked, possible definitions can include:
- Which page (blueprint or Live Copy) has priority during rollout
- Which pages are renamed, and how
- How this affects any published content
The default behavior of Adobe Experience Manager (AEM) out-of-the-box is that published content is not impacted. So, if a page that was manually created in the Live Copy branch has been published, that content is still published after the conflict handling and rollout.
In addition to the standard functionality, customized conflict handlers can be added to implement different rules. These can also allow publishing actions as an individual process.
Example Scenario example-scenario
In the following sections, an example of a new page b is used, created in both the blueprint, and the Live Copy branch (created manually), to illustrate the various methods of conflict resolution:
-
blueprint:
/bA master page with one child page,
bp-level-1 -
Live Copy:
/bA page manually created in the Live Copy branch with one child page,
lc-level-1- Activated on publish as
/b, together with the child page
- Activated on publish as
Before Rollout before-rollout
bbbb that was manually created in the Live Copy branch/bp-level-1/lc-level-1/lc-level-1child-level-1 that was manually created in the Live Copy branchRollout Manager and Conflict Handling rollout-manager-and-conflict-handling
The rollout manager lets you activate or deactivate conflict management.
This is done using OSGi configuration of Day CQ WCM Rollout Manager. Set the value Handle conflict with manually created Pages ( rolloutmgr.conflicthandling.enabled) to true if the rollout manager should handle conflicts from a page created in the Live Copy with a name that exists in the blueprint.
AEM has predefined behavior when conflict management has been deactivated.
Conflict Handlers conflict-handlers
AEM uses conflict handlers to resolve any page conflicts that exist when rolling out content from a blueprint to a Live Copy. Renaming pages is the usual (not only) method of resolving such conflicts. More than one conflict handler can be operational to allow for a selection of different behaviors.
AEM provides:
- The default conflict handler:
ResourceNameRolloutConflictHandler
- The possibility to implement a customized handler
- The service ranking mechanism that lets you set the priority of each individual handler
- The service with the highest ranking is used.
Default Conflict Handler default-conflict-handler
The default conflict handler is ResourceNameRolloutConflictHandler
- With this handler, the blueprint page is given precedence.
- The service ranking for this handler is set low. That is, below the default value for the
service.rankingproperty because the assumption is that customized handlers need a higher ranking. However, the ranking is not the absolute minimum to ensure flexibility when required.
This conflict handler gives precedence to the blueprint. For example, the Live Copy page /b is moved within the Live Copy branch to /b_msm_moved.
-
Live Copy:
/bIs moved within the Live Copy to
/b_msm_moved. This acts as a backup and ensures that no content is lost.lc-level-1is not moved.
-
Blueprint:
/bIs rolled out to the Live Copy page
/b.bp-level-1is rolled out to the Live Copy.
After Rollout after-rollout
bbb_msm_movedbb that was rolled outb that was manually created in the Live Copy branchb that was manually created in the Live Copy branch and is now called b_msm_moved/bp-level-1/bp-level-1/lc-level-1/lc-level-1Customized Handlers customized-handlers
Customized conflict handlers allow you to implement your own rules. Using the service ranking mechanism you can also define how they interact with other handlers.
Customized conflict handlers can:
- Be named according to your requirements.
- Be developed/configured according to your requirements.
- For example, you can develop a handler so that the Live Copy page is given precedence.
- It can be configured using the OSGi configuration. In particular the:
- Service Ranking defines the order related to other conflict handlers (
service.ranking).- The default value is
0.
- The default value is
- Service Ranking defines the order related to other conflict handlers (
Behavior When Conflict Handling is Deactivated behavior-when-conflict-handling-deactivated
If you manually deactivate conflict handling, AEM takes no action on any conflicting pages. Non-conflicting pages are rolled out as expected.
In this case, the Live Copy effectively takes precedence. The blueprint page /b is not copied and the Live Copy page /b is left untouched.
-
Blueprint:
/bIt is not copied at all, but is ignored.
-
Live Copy:
/bIt stays the same.
After Rollout after-rollout-no-conflict
bbbb that was manually created in the Live Copy branchb that was manually created in the Live Copy branch/bp-level-1,/lc-level-1/lc-level-1Service Rankings service-rankings
The OSGi service ranking can be used to define the priority of individual conflict handlers.