Squid access log is very informative if you know how to dig something out of it. Following is an a line from access.log file. 1201172176.719 1190 127.0.0.1 TCP_MISS/200 529 GET http://www.blogger.com/status.g? - DIRECT/72.14.221.191 application/xml This line can be written as: Timestamp, Total time, Source, Action/Code, Size, Method, URL, Ident, Hierarchy/From, Content type 1: Timestamp Time when the request was completed. 2: Total time Total time taken to complete the request 3: Source IP address of the client 4: Action/Code Action taken for the request 5: Size Total size of the request in bytes 6: Method Whether the request was GET or POST 7: URL The actual request 8: Ident Usually - 9: Hierarchy/From How the object is fetched and from where 10: Content type Type of object Action "TCP_" refers to requests on the HTTP port (3128) TCP_HIT A valid copy of the requested object was in the cache. TCP_MISS The requested object was not in the cache. ...