[OpenAFS] 1.4.8, Rx Performance Improvements, and a Small Business Innovative Research grant
Ken Hornstein
kenh@cmf.nrl.navy.mil
Fri, 03 Oct 2008 09:58:31 -0400
>With those observations... does rx-over-tcp look like a solution? On
>the packet-transmission side probably, but the encapsulation very
>likely still demands significant processing power. And running a
>server with 10000 or 20000 TCP connections does not sound that obvious
>either.
Here's what I can tell you, based on my experience:
- The encapsulation for rx-over-tcp wasn't, in my experience, a huge
performance sink. The trick was trying to create a protocol that
didn't starve multiple writers who were trying to use the same
connection. I think I made some decent progress on this; I was able
to convince myself that the problem wasn't insurmountable.
- Web servers seem to manage this sort of thing fine (admittedly, there
are a lot of front-end devices they can use than OpenAFS cannot, but
still, a lot of work has been done on handling tons of TCP connections).
There are some obvious ways of dealing with this. I think in practice
it will be a non-issue.
--Ken