CloudFront “age” header effect on “cache-control: private; max-age=3600”

Question

I am using CloudFront with fixed cache time (say 1 day) for a particular static resource. At the same time, I want the browser to cache that only for one hour, that's why the response is:

cache-control: private; max-age=3600

However, CloudFront is always adding a response header:

age: 35

Which is the number of seconds that has been cached on the proxy (CloudFront in this case).

Reading https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching really makes sense and there's no mention of age header. What is possible is that header has value of say 24678 seconds, and the resource would be considered expired.

I just want to confirm that that age header has no effect on the local browser cache. Am I correct?

Answer 1

Unfortunately after a couple of hours of testing and experiments, it doesn't seem possible to achieve what I wanted - cache a resource in CloudFront for long period (say 1 day) but make this cached in the browser for 30 mins.

The age header affects the expiration of a HTTP resource.

Eg if you have cache-control: private; max-age=3600 cache-control: private; max-age=3600 and you try to fetch a resource from CloudFront with age: 4000 then this resource is considered already expired by the browser and next time it has to be re-downloaded again.