重复加载JSONP在Safari，Chrome中不起作用

Question

I'm using JSONP to load frequently updating score data from my CDN. The JSONP file is loaded via a single URL which never changes from request to request. It works without issue in Firefox and IE, but in Webkit (Safari and Chrome specifically), I'm seeing the file only getting loaded off the server once; after that, the file -- and its old data -- is simply reloaded from cache in these browsers.

I can prevent this behaviour by throwing a random number at the end of the URL (or otherwise making the request unique), but then our CDN (Akamai) would simply forward the request from each and every user and our origin servers would melt.

Does anyone know of any other way to do JSONP efficiently with a CDN?

Answer 1

Your problem is the Cache-Control: you are telling Akamai (which tells your browser) how long to keep the version of the file. You have to figure out ahead of time how long the current version of the file and have your webserver set the Cache-Control header correctly.

It's a complicated subject, but your Akamai rep can help (mine helped me).