UDP output performance

Mike Tancsa mike at sentex.net
Mon Sep 7 13:39:08 UTC 2009


At 07:40 AM 9/7/2009, Willem Jan Withagen wrote:

>Well this turns out to be a pilot error, in that I created such a 
>complex bandwidth evaluation that on buffer full the packet got 
>tossed in the application.
>:(
>
>Just stripping that out, and just do a
>
>try send
>while(not send) {
>         usleep(1 packet-time);
>         try again;
>}

There are some nice simples tool in /usr/src/tools/tools/netrate that 
are great for generating arbitrary bandwidth via udp packets you 
might want to have a look at.

         ---Mike


>
>Reduced my packet loss to < 0.1% and I'm able to squeeze a nice > 
>900 Mbit/s  out of a single em(4) port. Still no packets begin 
>dropped in netstat -i.
>
>So now I'm off hunting for 'bugs' in snmp, cacti, mrtg to see why 
>they don't like the counters. Even when I'm using the 64bit counters 
>I get really spiky  bandwidth results. Equal to those when using 32 
>bits counters, so certainly things are not as I think they are.
>
>Other thing is to see how Lin* is performing on this test.
>So trying to install ubuntu 9.04.
>
>--WjW
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--------------------------------------------------------------------
Mike Tancsa,                                      tel +1 519 651 3400
Sentex Communications,                            mike at sentex.net
Providing Internet since 1994                    www.sentex.net
Cambridge, Ontario Canada                         www.sentex.net/mike



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