Dynamic Media image asset updates delayed by CDN cache retention
Adobe Experience Manager (AEM) Dynamic Media image assets continue displaying outdated content after asset replacement or republication when cached Dynamic Media URLs continue serving older binary versions. This issue occurs because Dynamic Media delivers assets through a CDN that retains cached image content for a defined TTL period and does not automatically invalidate cached URLs when an asset is updated. To resolve the issue, invalidate the cache, verify assets, and confirm delivery.
Description description
Environment
- Adobe Experience Manager (AEM) Dynamic Media
- Adobe Experience Manager as a Cloud Service (AEMaaCS)
- Adobe Experience Manager (AEM) Managed Services
Issue/Symptoms
- A Dynamic Media URL continues to display an older image after the asset is replaced. For example, the replacement image updates in the search thumbnail, but the full-view Dynamic Media URL still displays the previous binary.
- Adding a cache-busting query parameter displays the updated image. For example, appending a parameter such as
?abc=xyzto the image URL returns the updated content, which confirms CDN caching. - Dynamic Media Classic displays the updated binary, but the base delivery URL continues to serve the previous version.
- Rendition URLs such as
/jcr:content/renditions/...display inconsistent behavior by showing updated content when a query string is present and stale content when no query string is present. - Republished or reprocessed assets continue to display outdated content on websites and Dynamic Media delivery URLs.
Root cause
The issue occurs because Dynamic Media assets are delivered through a CDN that caches image content for approximately ten hours. When an asset is replaced with the same name, the CDN continues serving the previously cached binary until the cache expires or the specific URL is invalidated. Cache invalidation is URL-specific, and custom CDNs require separate purge actions outside Adobe-managed infrastructure.
Resolution resolution
Follow these steps to identify cached URLs and restore updated Dynamic Media content:
- Identify the exact Dynamic Media delivery URLs that continue serving outdated content, including base URLs, preset URLs, and deep-path URLs.
- Confirm that AEM contains the updated asset by reviewing the asset details, thumbnails, and renditions in the author environment.
- Invalidate the CDN cache through AEM by navigating to Tools
>Assets>CDN Invalidation, entering the affected Dynamic Media URLs, and submitting the invalidation request. - Invalidate the CDN cache through Dynamic Media Classic by navigating to File
>Invalidate CDN and submitting the affected delivery URLs when using Dynamic Media Classic. - Purge the cache directly in the CDN provider platform when the environment uses a customer-managed CDN.
- Confirm CDN caching by appending a random query parameter to the URL and comparing the returned image with the original URL response.
- Validate the resolution by loading each Dynamic Media URL in a clean browser session, verifying updated content without cache-busting parameters, and confirming that presets, width modifiers, and rendition URLs also display the updated asset.
When to escalate
- The updated image does not appear after successful CDN invalidation.
- The invalidation request returns errors or does not complete successfully.
- The image remains stale when accessed through Adobe-managed Dynamic Media URLs after cache invalidation.
- Cache-bypass testing indicates that the asset update does not exist in Dynamic Media delivery services.