|
Hi,
Some of the emerging redirection switches on the
market support something known as Level 7 redirection
which essentially allows the redirector to look at the
start of the TCP data stream, by spoofing the initial
connection and making load balancing based on what it
sees there. (Apologies if I'm doing the equivalent of
"teaching your grandma to suck eggs", but at least this way
there's less mis-understanding of what I'm getting at/after)
For example if we have X proxy-cache servers, we could
spoof an HTTP connection, grab the requested URL, and
hash it to one of those X servers. If it was possible
to look inside individual UDP packets as well, then we
would be able to route ICP (inter cache prototol) packets
in the same way. The result is a cluster that looks like
a single server to clients.
For generic HTTP servers this could also allow the server
to farm cgi-requests to individual machines, and the normal
requests to the rest. (eg allowing you to buy a dual/quad
processor to handle soley cgi-requests, but cheap/fast
servers for the main donkey work.)
We've spoken to a number of commercial vendors in the past
who are developing these things but they've always failed
to come up with the goods, mainly citing incompatibility
between our needs and their designs :-/
Any ideas how complicated this would be to add to your
system?
Michael.
--
|
