[netperf-talk] Issues using parallel sessions of netperf

[Rick Jones]

> >>>> Here's a sample output:
> >>>> bin/netperf -l30 -P0 -fk -t TCP_MAERTS -p14536 143.215.129.122
> >>>> bin/netperf -l30 -P0 -fk -t TCP_MAERTS -p14536 143.215.129.122
> >>>> bin/netperf -l30 -P0 -fk -t TCP_MAERTS -p14536 143.215.129.122
> >>>> send_tcp_maerts: data recv error: Interrupted system call
> >>>>
> >>>> In this example, one session failed. I tried opening 3 instances of
> >>>> netserver on the server on 3 ports, but the same error occurred.
> >>>>
> >>>> I'm using netperf 2.4.5 on Linux 2.6.32. Please let me know if you need
> >>>> more information. Any help would be greatly appreciated.
> >>>
> >>> My initial guess is that the end-of-test timer is firing when it was not
> >>> expected to - perhaps the rate of data flow through the broadband link
> >>> into the netperf(s) is such that the remote's close does not happen
> >>> before the watchdog timer pops?
> >>>
> >> This testing is in an academic network (1Gbps connection between 2
> >> servers). I was able to replicate it on a broadband link (though I only
> >> ran the experiment a couple of times). Is there any more information
> >> that I can give you that might help in debugging the issue?
> > 
> > How much time passes before the error message(s) appear?
> > 
> 
> I'm running the test for 30 seconds. It occurs after 10s or so.

redirect both stdout and stderr so each netperf has their own file and
add a global -d option.  perhaps we can then see what signal is arriving
and interrupting a recv call.

That or system call trace each of the netperfs to try to get the same
result.

rick