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? Regards, solomon. --- Henrik Nordstrom <henrik@xxxxxxxxxxxxxxxxxxx> wrote: > On mån, 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 >
