Process limits for epoll tests

Process limits for epoll tests

[Philippe Meloche (LMC)]

Hi,

We tried to reproduce the tests you've done with /dev/epoll and we've 
come to ask us some questions.

1. How did you managed httperf to perform more than 1024 connections 
when it's using select() ?

2. Did you get some errors like client-timeout or connections reset when 
you were doing your tests ?

3. How much time did a burst test ( 27000 connections and 2 calls per 
connection ) last and how many sample did httperf
    took during those tests.

Thanks a lot

Philippe Meloche
philippe.meloche@lmc.ericsson.se

Re: Process limits for epoll tests

[Davide Libenzi]

On Tue, 1 Apr 2003, Philippe Meloche (LMC) wrote:

> Hi,

Hi,


> We tried to reproduce the tests you've done with /dev/epoll and we've
> come to ask us some questions.

I hope you are not using the old /dev/epoll since it is no more supported.
The kernel 2.5.x has epoll, that is supported :

http://www.xmailserver.org/linux-patches/epoll.txt
http://www.xmailserver.org/linux-patches/epoll_create.txt
http://www.xmailserver.org/linux-patches/epoll_ctl.txt
http://www.xmailserver.org/linux-patches/epoll_wait.txt



> 1. How did you managed httperf to perform more than 1024 connections
> when it's using select() ?

Yes, you can't have more than 1024 simultaneous connections with httperf.
But if the session time is short, you can achieve a pretty high rate with
1024 maximum connections. Lately I am using the http blaster ( ver very
simple http loader ) that uses epoll. The latest source code is here :

http://www.xmailserver.org/linux-patches/epoll-lib-0.7.tar.gz

You need this coroutine library to build that package :

http://www.xmailserver.org/libpcl.html



> 2. Did you get some errors like client-timeout or connections reset when
> you were doing your tests ?
>
> 3. How much time did a burst test ( 27000 connections and 2 calls per
> connection ) last and how many sample did httperf
>     took during those tests.

You definitely have to tweak kernel/net params to run the test ( port
range, fin timeout, tw recycle, max files, ... ).




- Davide