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Akamai • Akamai, Mirror Image
Akamai Content DistribuOon Networks have servers around the world They distribute your content so downloads can come from a nearby locaOon Major CDN providers are – Akamai • –
– Distributes OS X and iOS updates SAVVis Limelight OnApp BityGravity Amazon CloudFront distribute your static content before distributing your dynamic content Copyright 2009 - 2013 Horowitz 14 Rule 3: Add an Expires Header • All caches use a set of rules to determine whether to deliver an object from the cache or request a new version –
– If the object’s headers tell the cache not to keep the object, it won’t If the object is authenOcated or secure, it wont be cached A cached object is “fresh” (able to be sent to a client without checking with the server) if • It has an expiry Ome or other age- controlling direcOve that is set and sOll within the fresh period • If a browser cache has already seen the object and has been set to check once a session • If a proxy cache has seen the object recently, and it was modiﬁed long ago – If an object is “stale”, the origin server will be asked to validate the object or tell the cache whether the copy that is has is sOll good • As part of HTTP protocol there is a Cache- Control header • HTTP headers are sent by the server before the HTML, and only seen by the browser and any intermediate caches....
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- Spring '07
- Web page, World Wide Web, Cascading Style Sheets, Horowitz