Re: The cache deny QUERY change... partial rollback?

2008/12/1 Henrik Nordstrom <henrik_at_henriknordstrom.net>:
> After analyzing a large cache with significantly declining hit ratio
> over the last months I have came to the conclusion that the removal of
> cache deny QUERY can have a very negative impact on hit ratio, this due
> to a number of flash video sites (youtube, google, various porno sites
> etc) who include per-view unique query parameters in the URL and
> responding with a cachable response.
>
> Because of this I suggest that we add back the cache deny rule in the
> recommended config, but leave the refresh_pattern change as-is.
>
> People running reverse proxies or combating these cache busting sites
> using store rewrites know how to change the cache rules, while many
> users running general proxy servers are quite negatively impacted by
> these sites if caching of query urls is allowed.

Hm, thats kind of interesting actually. Whats it displacing from the
cache? Is the drop of hit ratio due to the removal of other cachable
large objects, or other cachable small objects? Is it -just- flash
video thats exhibiting this behaviour?

Are you able to put up some examples and statistics? I really think
the right thing to do here is look at what various sites are doing and
try to open a dialogue with them. Chances are they don't really know
exactly how to (ab)use HTTP to get the semantics they want whilst
retaining control over their content.

Adrian
Received on Mon Dec 01 2008 - 14:40:11 MST