On Tue, Sep 18, 2007, Solomon Asare wrote: > Hi Henrik, > thanks for your insightful response. However, the > object is a .flv file that hasn't changed in months. > The origin server certainly doesn't want the object > cached, but I want to. Any leads that can help me > achieve this? * set your refresh_pattern's right, you can override almost all the relevant headers in there; * if the URL has a ? in it then you need to look at the cache/no_cache directives * if in doubt, compile with the option to log request/reply headers (I forget what it is, ./configure --help will tell you) and take a look at exactly what headers they're sending back. Adrian > Regards, > solomon. > > --- Henrik Nordstrom <henrik@xxxxxxxxxxxxxxxxxxx> > wrote: > > > On m?n, 2007-09-17 at 11:55 -0700, Solomon Asare > > wrote: > > > Hi Amos, > > > I am not sure if refresh_pattern is the sole > > > determinant in caching an object, that is if it > > has > > > any influence at all. > > > > It has influence, both directly by assigning > > freshness information when > > there is none, and indirectly by overriding various > > HTTP controls.. > > > > Requirementsto cache stale objects: > > > > a) The object must have a cache validator > > (Last-Modified or ETag). If > > there is no cache validator then the response must > > be fresh for at least > > minimum_expiry_time to get cached, this to avoid > > wasting disk I/O for > > caching content which can not be reused. > > > > b) There must not be other headers preventing it > > from getting cached. > > refresh_pattern can override most of these if > > needed. > > > > > I am not discussing getting a > > > HIT for a cached object, but rather caching an > > expired > > > object from an origin server. If this object is > > > expired, by say 60 seconds before being served > > from > > > the origin server, how do I cache it? Date and > > > Last-Modified dates are also not set. > > > > If there is no Last-Modified and no ETag then it's > > useless to cache an > > expired object, as it can not be reused on any > > future request and all > > you get is extra disk I/O for writing the object > > out. > > > > A cache validator (Last-Modified or ETag) is > > required to be able to > > verify with the origin server if an expired object > > is still valid or > > not. Without a cache validator there is nothing to > > relate to and there > > is no other choice than to fetch the complete object > > again when > > expired.. > > > > Regards > > Henrik > > -- - Xenion - http://www.xenion.com.au/ - VPS Hosting - Commercial Squid Support - - $25/pm entry-level bandwidth-capped VPSes available in WA -
