Re: squid disk cache

On 10/04/2011 12:03 PM, pavi wrote:

> whenever a client sends a request how does the proxy server identifies
> whether the requested object is in the disk cache or not

Squid computes a "key" using Request-URI, Request method, and other
transaction properties and then looks up that key in one or more storage
indexes. If there is a match, the requested object is probably in the
cache. Additional checks are performed as the identified stored object
entry is located and swapped in.

With SMP caching, there are up to three kinds of storage indexes:

  * shared memory cache index (if memory caching is enabled);
  * shared disk cache indexes (one per Rock cache_dir, if any); and
  * local index of in-transit objects (unused to the extent possible).

Without SMP caching, there is just one global storage index where all
stored objects are recorded.

HTH,

Alex.
Received on Tue Oct 04 2011 - 19:13:36 MDT