[netperf-talk] Help me to understand the results

[Steevan Rodrigues]

Hi Rick,

Thanks for the details.
Can I consider the result even when there is a warning about confidence
level ?
Will  that lead to inaccuracy ?

Also what happens when I use -r options (i.e  Allow confidence to be hit on
result only) ?
Is it more accurate or is to ignore confidence warning ?

Thanks,
Steev


On Thu, Jan 13, 2011 at 11:58 PM, Rick Jones <rick.jones2 at hp.com> wrote:

> Steevan Rodrigues wrote:
>
>> Hi,
>>
>> I am newbie to netperf.
>> I ran following command
>> $ /usr/local/bin/netperf -l 5 -H 192.168.11.207 -t TCP_STREAM -c LOC_CPU
>> -C REM_CPU -i 10,2 -I 95,3 -- -m 1 -s 32768 -S 32768
>>
>> And obtained following output (please see below). Can you please explain
>> me following ?
>> 1) Why there is a warning about desired "Confidence level" ?
>>
>
>
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#index-g_t_002dI_002c-Global-26
>
>
>  2) When I include -c LOC_CPU  -C REM_CPU  I get  details about
>> "utilization" and "Service Demand" . What do they represent ?
>> Do they represent local and remote CPU utilization ?
>>
>
> I suspect there has been some cut-and-paste confusion from a script
> somewhere as I would expect that to be $LOC_CPU and $REM_CPU.  Regardless
> the -c option requests measurement of local CPU utilization, -C requests
> measurement of remote CPU utilization.
>
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#CPU-Utilization
>
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#index-g_t_002dc_002c-Global-18
>
>
>  3) How max and min number of iterations are actually used ?
>>
>
> See the URL in the answer to 1.
>
>
>  4) Actually I want to measure throughput vs CPU Load for my system.
>>   What is the best command for the above purpose ?
>>
>
> Are you trying to say you want to measure what throughput can be achieved
> at discrete levels of CPU utilization?   That may be something of a
> challenge.
>
> It may be possible to measure CPU utilization at a given throughput level
> via:
>
>
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#index-g_t_002dw_002c-Global-39
>
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#index-g_t_002db_002c-Global-16
>
> However, achieving a given level of throughput can be accomplished with
> more than one set of values for -b and -w, which may affect the CPU
> utilization. Toss-in the effect of the various values of the -m
> test-specific option and one is really talking about a rather large space.
>
>
>  5) Do I need to use a crossover cable for the test setup ?
>>
>
> 1GbE and later networking does not require a cross-over cable.  100BT and
> below does.
>
>
>  6) Can I have multiple servers and one client ? Or multiple client and one
>> server setup ?
>>
>
>
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#Using-Netperf-to-Measure-Aggregate-Performance
>
>
>  ==================================================
>> TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.11.207
>> (192.168.11.207) port 0 AF_INET : +/-1.500% @ 95% conf.
>> !!! WARNING
>> !!! Desired confidence was not achieved within the specified iterations.
>> !!! This implies that there was variability in the test environment that
>> !!! must be investigated before going further.
>> !!! Confidence intervals: Throughput      : 1.164%
>> !!!                       Local CPU util  : 0.000%
>> !!!                       Remote CPU util : 56.955%
>>
>> Recv   Send     Send                                         Utilization
>>     Service Demand
>> Socket Socket  Message  Elapsed                     Send     Recv     Send
>>    Recv
>> Size     Size     Size           Time     Throughput    local    remote
>> local   remote
>> bytes    bytes   bytes         secs.    10^6bits/s      % S      % S
>>  us/KB   us/KB
>>
>>  65536  65536      1             5.00          9.46        100.00   59.60
>>    865.994  516.212
>> ==============================================================
>>
>> Thanks for your help,
>> Steevan
>>
>>
>> ------------------------------------------------------------------------
>>
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>
>
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