I'm utilizing both CloudFlare and MaxCDN for my website; MaxCDN handles images and scripts while CloudFlare handles HTML pages (in terms of CDN). I'm not using a custom subdomain for MaxCDN (i.e. I'm using their URLs instead of my own subdomain).
I'm looking at the headers in Chrome for my website, and it is showing that the CloudFlare cache as a HIT for MaxCDN URLs. Huh? What is going on? How (and why) is CloudFlare caching resources on MaxCDN URLs -- I thought CloudFlare caches resources on your own domain only?
I'm asking because, ideally, I want my caching stack to be CloudFlare -> MaxCDN -> my server. In other words, if CloudFlare has a cached resource, it should serve it; if not, it should send users to MaxCDN (when applicable, such as for images and script). So first I need to understand what is going on.