We have a requirement where we want to pre-warm the cache of all the edge server for a specific CloudFront distribution. For this, we will need to direct a few calls to all the edge servers. Is there any way of identifying all edge servers within a region or globally?
For example:
When going through the information available here: http://aws.amazon.com/cloudfront/details/
I found that there are multiple edge servers within Asia, lets take Mumbai (India) and Hong Kong for example, I am interested in directing a few HTTP calls to these edge servers. How can I achieve this? If I can get the identity of all these servers, that will be great.
Also, we originally thought of the following approach: Have a micro instance in all the regions, and access our assets from them.
But there is a problem with this approach. From CloudFront documentation, I have come to understand that there is no hierarchal structure between the edge servers, if any of the edge server does not have the required asset, it directly ask Origin server for that asset. Now, a single region can have multiple edge servers. If within a region, all the edge servers are not having the required assets, then it defeats the purpose of doing this exercise. So, my question is how to ensure that all the edge servers in a region have the required assets in their cache?
Please note that the content is static in nature. And if covering all edge servers is not possible then even if there is an approach which can cover, lets say, 70% of the edge servers, I would like to try that.
Here is a post from an Amazon employee from a few years ago regarding pre-warming:
The issue is, if everyone pre-cached objects to a edge location all of the edge locations would run out of space because they would be flooded with objects that may or may not be being accessed. Right now the edge location only caches objects that are being accessed by users and will dump objects that have no been accessed recently if there is no more room on the server. I am not sure how a pre-cached scenario would work if it were a service.
Unless you know that you're going to be getting a steady flow of traffic over an extended period of time then pre-warming simply may not be effective. CloudFront may very well expire your objects to make room for other customers objects if they're getting more (or more recent) traffic than your own. Once that happens you've completely lost the advantage of any pre-warming you're able to perform.