Last modified time of a DAM resource

[pnagy]

Hi,

when querying an image resource from AEM (e.g. /content/dam/blackrock/440px-AdamSmith.jpg) the value for Last-Modified header in the response does not match the jcr:lastModified timestamp value in the CRX. I would expect them to be the same, can you please help why they could differ?
I have attached the screenshots for both values.

Regards,
Peter

[arunpatidar]

Hi @pnagy 
One of the reason could be that assets has different modify time on publisher or cached copy at dispatcher.

Could you please check timestamp at dispatcher?

[pnagy]

Hi @arunpatidar ,

Thanks for all the replies. TBH not sure how I can check the dispatcher but that was an author instance I used for testing.
I have uploaded a new image on my local where I don't have any dispatcher / CDN, and the same behaviour (the difference in hours is just timezone difference but there is 18 sec difference yet).

Regards,
Peter

[gkalyan]

@pnagy I tried to verify on my instance for multiple assets, but I don't see this issue(the timestamp is same on both locations). 

I understand the curiosity piece of it but is there a specific use case you are trying to solve with Last Modified?

I'm curious to see what is the jcr:lastModified on the metadata node. Can you share.

[gkalyan]

@pnagy 

Dates in both locations seem to be same except for the format. ISO vs verbose/human readable.

The small difference in seconds might be due what @arunpatidar explained. The Last-Modified header is typically set by the Dispatcher cache, not directly from the JCR repository. If you are hitting the from Author instance, it should be the same.

[MukeshYadav_]

Hi @pnagy ,

Timestamp jcr:lastModified on AEM instance and  last-modified in browser network console can  be different because content  served to end user might be from 

• CDN or
• Dispatcher

which can be different based on last flushed cache or minute time taken in replication.

Thanks