What are private and public keys?
keys refers to the database keys which Squid uses to index cache objects. Every object in the cache–whether saved on disk or currently being downloaded–has a cache key. For Squid-1.0 and Squid-1.1 the cache key was basically the URL. Squid-2 uses MD5 checksums for cache keys. The Squid cache uses the notions of private and public cache keys. An object can start out as being private, but may later be changed to public status. Private objects are associated with only a single client whereas a public object may be sent to multiple clients at the same time. In other words, public objects can be located by any cache client. Private keys can only be located by a single client–the one who requested it. Objects are changed from private to public after all of the HTTP reply headers have been received and parsed. In some cases, the reply headers will indicate the object should not be made public. For example, if the no-cache Cache-Control directive is used.
keys refers to the database keys which Squid uses to index cache objects. Every object in the cache–whether saved on disk or currently being downloaded–has a cache key. We use MD5 checksums for cache keys. The Squid cache uses the notions of private and public cache keys. An object can start out as being private, but may later be changed to public status. Private objects are associated with only a single client whereas a public object may be sent to multiple clients at the same time. In other words, public objects can be located by any cache client. Private keys can only be located by a single client–the one who requested it. Objects are changed from private to public after all of the HTTP reply headers have been received and parsed. In some cases, the reply headers will indicate the object should not be made public. For example, if the no-cache Cache-Control directive is used.
