Flash Player and AIR send AMF requests in the body of HTTP POST requests. The POST method (http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html - section 9.5) is technically not cacheable by HTTP components (proxies, browsers, etc.) unless the AMF endpoint explicitly enables this by setting necessary HTTP response headers to allow caching. I think in general, AMF endpoints do the opposite and set response headers to explicitly disallow caching to deal with old buggy proxies that cache things they shouldn't.
Because your Flex app is running in a stateful client, the need for caching along the network path is reduced. Your app can hang onto data from the server as long as you think is prudent, and it can fetch more or refresh existing data as needed. Traditional web apps on the other hand often end up triggering many "duplicate" requests as the user navigates forward and back through pages, so caching along the network path is essential to protect your servers from inadvertent DoS attacks :) Best, Seth From: flexcoders@yahoogroups.com [mailto:flexcod...@yahoogroups.com] On Behalf Of Mike Oliver Sent: Sunday, January 11, 2009 4:26 PM To: flexcoders@yahoogroups.com Subject: [flexcoders] Server Side Cache and AMF What are the pros and cons to using a serverside cache or proxy cache with Flex and AMF? I can see a cache on a web service that is primarily a lookup service, but don't see much if any benefit to a cache related to transactions, and for lookup, except for really large data sets I think a client side actionscript object will be every bit as effective, and for really large data sets you don't want to fetch more than you need anyway so a cache won't do much there either. I think server side cache is best for pages of information like HTML pages, XML documents, JSP pages where the content is keyed in the cache by the URL for the GET, and anything else is a waste of effort or worse due to stale data in the cache. But what do I know? If I knew everything I wouldn't ask.
