eventual incorporation of push and hint cache into Squid-HEAD?

-- I would like to discuss the desirability of incorporating push into
the main branch once it is reasonably stable.

Push basically consists of three protocol bits:

     PUT to a neighboring cache
     dist to a tree of 'interested' caches.
     Hint caching

The hint cache basically amounts to a distributed metadata system for
cached objects.

There are all sorts of reasons why it's worth while to incorporate
it. I'll start with the most convincing to you. Hint caching speeds
up old-fashioned pull caching in clouds of caches better than even
cache digests. It solves the need for big arrays of caches.

See http://www.pushcache.com/tr98-04.pdf for details about hint
caching.

It also supports push. That means that clouds of caches can now be
used for all manner of push applications, from prepush of important
content, to satellite push, to video push eventually.

See http://www.pushcache.com/wp1.html for details about push.
 
In the long run, these push applications could get quite interesting.
Pushcaches are potentially invaluable to push of everything from vital
business information to video to virtual world updates.

On the research side,it could be used to support research into RUP
protocols.

Disadvantages up front: push and hint caching are big, weighing in at
over 8,000 lines spread over eleven files. An operational hint cache
consumes 80-160M of disk space for Cache-Digest-like stuff.

And, of course, this only matters if I actually get enough of the port
to Squid-HEAD done to be worth doing. But I thought it would be worth
starting the argument today, in case people have doubts.

In short, push can help with just about anything but motherhood. :-)

Once again, the biggest immediate reason to incorporate this feature
is lower latency from clouds of hint caches vs. clouds of pushless
Squids.

--
Jon Kay        pushcache.com                      jkay@pushcache.com
http://www.pushcache.com/                             (512) 420-9025
Squid consulting				  'push done right.'