AEMaaCS: how do I know if a file is getting served from dispatcher vs CDN?

[jayv25585659]

1. when I worked on a AEM setup usng managed services, Cloudfront inserts extra response header that will tell me if the page is getting served from CDN or from origin.
2. Because it managed service, I can login to the dispatcher and I can manually check if the page is already cache in the dispatcher or needs to be fetched from the publisher.

How can I do both of these on AEMaaCS?

[giuseppebag]

hi @jayv25585659,

For AEMasCS you can determine if a file is served from the CDN or the Dispatcher by examining the HTTP response headers.

The Adobe-provided CDN (Fastly) in AEMaaCS typically adds a debug header that indicates the cache status: look for the X-Cache response header.

Values meaning:

• HIT: The resource was served from the CDN cache
• MISS: The resource was not found in the CDN cache and was fetched from the origin (which is the AEM Dispatcher/Publish stack)
• EXPIRED: The resource was cached but had expired, so it was fetched again from the origin.

In short, if the X-Cache header value is anything other than HIT (typically MISS or EXPIRED), the request has hit your Dispatcher/AEM Publish stack.

[jayv25585659]

is there a way to know if the page is already in the dispatcher or had to be fetched from the publisher?

In managed services, it's easy to check this (as I mentioned above) since clients can login to the dispatcher.

Thanks again.

[giuseppebag]

Check the AEM Dispatcher log, a Dispatcher cache HIT will be visible in Dispatcher access logs but not in AEM Publish request.log, whereas a MISS/PASS will appear in both layers.

You can download the log file from Cloud Manager, or if you use Splunk, you can query the log (see this response here)

[arunpatidar]

Hi @jayv25585659 

You can also check the Last-Modified response header. If Date and Last-Modified are same then page is served from publisher, if not then it is either from CDN or dispatcher cache.