From e8aaa4074ab1689795de9376460261cc2c466fa5 Mon Sep 17 00:00:00 2001 From: Kliment Mamykin Date: Sun, 17 Apr 2011 08:10:55 -0400 Subject: [PATCH] Updated README with CloudFront known issues --- README.md | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/README.md b/README.md index 44bdc56..2e3c197 100644 --- a/README.md +++ b/README.md @@ -94,6 +94,25 @@ distribution, and you will see Distribution ID and Domain Name values. This will use the CloudFront domain name for your assets instead of serving them from the (slow) S3 bucket. +### Known issues with CloudFront invalidation + +1. It may reportedly take up to 15 minutes to invalidate all the CloudFront +caches around the globe (and Amazon charges for more than a certain number +of invalidations per month). + +2. It's non-atomic from the perspective of the end-user: They may get an +older version of the site with a newer version of the JavaScript and CSS, or +vice versa. + +3. It doesn't play nicely with aggressive HTTP caching. For example, once I +serve a script or a stylesheet, I would like it to be cached indefinitely +with no more round trips to see whether it is valid. + +Given these constraints, there's still an important need for some kind of +content-based hashing. Done right, this assures that all files can be cached +indefinitely, and the user will always get matched HTML/JS/CSS files. (This currently +is in the works). + ## Bugs / Feature Requests To suggest a feature or report a bug: