If you set the TTL for a particular origin to 0, CloudFront will still cache the content from that origin. It will then make a GET request with an If-Modified-Since header, thereby giving the origin a chance to signal that CloudFront can continue to use the cached content if it hasn't changed at the origin.
I wonder how well this works for content that is truly dynamic. Seems like it would necessarily be slower for those pages that change on every request.
I wonder how well this works for content that is truly dynamic. Seems like it would necessarily be slower for those pages that change on every request.