DocumentationExperience Cloud KCS

Cloud Manager pipeline stalls and fails when the preview dispatcher is not ready

Last update: August 18, 2026

This article explains how to resolve AEM as a Cloud Service deployment pipelines that remain in a starting state for hours and then fail when the preview dispatcher does not become ready in time.

Description description

Environment

  • Adobe Experience Manager (AEM) as a Cloud Service
  • Cloud Manager deployment pipelines using dispatcher configurations with managed rewrite maps

Issue/Symptoms

  • The deployment pipeline remains in a starting or warming-up state for an extended period before failing.
  • The dispatcher startup and readiness checks failures are seen in the logs related to content/dam/rewrites/redirects.
  • Cloud Manager shows a generic deployment failure message after a long delay.
The deployment failed due to a system issue. Contact Adobe Support if the issue recurs.
  • Build and code quality steps complete successfully, but the deployment does not progress normally afterward.
  • The issue can occur even when the same branch or code deployed successfully in previous runs.
  • This is more likely when the project uses managed rewrite maps and preview dispatcher startup is delayed.

Reproduction conditions

  • Attempting to deploy code (even previously successful code) to the development environment using Cloud Manager.
  • The preview dispatcher or related preview services do not become healthy within the expected timeframe.
  • The pipeline fails after a long wait, or completes successfully but with an unusually long runtime.

Cause

The deployment pipeline hangs and eventually fails because the preview dispatcher container does not reach a ready state, causing Cloud Manager to wait until a timeout occurs. Updating the dispatcher YAML configuration to set the wait flag to false allows the preview dispatcher to start without blocking the pipeline.

Resolution resolution

To fix pipeline delays and failures caused by preview dispatcher startup blocking on managed rewrite maps, follow these steps:

  1. Confirm that all preview services, including the dispatcher, are configured correctly and can start without errors. Check Cloud Manager logs for any readiness or health check failures related to the preview dispatcher.
  2. Edit the dispatcher configuration YAML file, such as rewrite-maps.yaml or managed-rewrite-maps.yaml. Review the file for map entries that can block startup, and ensure that the wait flag is set to false for all map entries. For example:
maps:
        - name: redirects-301.map
        path: /content/dam/rewrites/redirects-301.txt
        ttl: 300
        wait: false
        - name: redirects-302.map
        path: /content/dam/rewrites/redirects-302.txt
        ttl: 300
        wait: false
  1. Save and commit the changes to your repository, then re-run the pipeline in Cloud Manager.
  2. Monitor the pipeline execution to confirm that the preview dispatcher and related services reach a healthy state in a timely manner instead of remaining in a prolonged starting or warming up state.
  3. After a successful deployment, verify that the dispatcher code has been deployed as expected.
  4. If the pipeline still takes longer than expected or fails, review the dispatcher and preview service logs for additional readiness, health check, or startup issues.
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