Does Squid cache "response headers" ?

nima0102 · 03-21-2010, 08:40 AM

Hi
One of our user inform me about some problems in viewing one site that he does not get fresh objects from site's server while site is updated everyday!!
After some investigate and dig on headers I get, I found out in response headers that "date" field is for 2 or 3 last week!!
1- Does Squid cache "response headers" ?If so, when user send "If-none-match" or "if-modified-since" in request header the cached "response header" will be updated?

Thanks in advance

bertl · 03-23-2010, 12:10 PM

I think it not so much caches them as honours them. If the response headers do not indicate any expiry information, or the document hasn't expired yet, and the headers and content show the document seems to be identical after the second or third fetch, squid would probably decide it can be cached for a while without re-checking.

A lot of sites don't send proper expiry information which makes life harder for caching web proxies and their users.

You might want to have a look at http://code.google.com/p/doctype/wik...cleHttpCaching and http://www.mnot.net/cache_docs/