Hi Thank you very much, after played around for sometime, concept about caching are much clear now! On Fri, Jun 6, 2008 at 4:00 AM, Henrik Nordstrom <henrik@xxxxxxxxxxxxxxxxxxx> wrote: > > There is a default refresh_pattern in the code, equal to > refresh_pattern . 0 20% 4320 > 1. Isn't this violating the standard (assuming the absence of squid as reverse proxy)? http://www.mozilla.org/projects/netlib/http/http-caching-faq.html expirationTime = responseTime + freshnessLifetime - currentAge RFC 2616: If only LM can be used, freshness = value of the "Date" header minus the value of the "Last-modified" header divided by 10... 2. Another interesting behavior I have tested is Squid will only store cache if expire > 60, where this value can be set? Thank very much. Howard