Re: "Predictive" caching

On Tue, Dec 07, 1999 at 02:26:38PM +0800, Miguel A.L. Paraz wrote:
> First of all thanks to those responded about my Squid "data mining" question.
> It was useful.
>
> Next, I'm thinking of something - I wonder what your thoughts on it are.
> It's something like "predictive caching", where you get objects in advance
> in anticipation of your users getting it. How do you know? Consider the
> situation where your cache has a peer whose users have the same usage patterns
> as yours. You log their ICP query MISSes and queue the objects up for
> fetching from your parent or the source, if they match certain criteria (like
> if the extensions are cachable, like gif, jpg, html).
>
> While this may increase the number of hits, the number of bytes downloaded
> also increases. However this is OK if the fetches are done during off-peak
> hours, or, there's a lot of bandwidth available but it's on a high-latency
> link like a satellite.

I think maybe you want to talk to the Skycache or Pushcache people.

The Skycache offering works exactly like what you describe - they log
miss/fetch requests from their clients all over the place, and then
feed the most popular ones out via the satellite link to the
pseudo-cache-server they've placed to peer with yours, so the hits get
stuffed into your cache before your users request them. (With Squid,
it does it by generating faked client queries for what it has in its
server, so that your Squid cache requests it from its "peer", the
Skycache box.) Mixed reports on how well it works in practice, but it's
cheap enough to make it worth using. You also end up with a very cheap
high-bandwidth Usenet newsfeed in the bargain.

I don't know if they can hit the Philippines with their satellite,
though. You'll have to talk to them.

I know less about Pushcache, but I think it works via terrestrial links
and compensates by doing more work to prioritize what it sends you.

  -- Clifton

-- 
 Clifton Royston  --  LavaNet Systems Architect --  cliftonr@lava.net
        "An absolute monarch would be absolutely wise and good.  
           But no man is strong enough to have no interest.  
             Therefore the best king would be Pure Chance.  
              It is Pure Chance that rules the Universe; 
          therefore, and only therefore, life is good." - AC