Re: [Make-wifi-fast] flent adds more text output

["Toke Høiland-Jørgensen" <toke@toke.dk>]

Sebastian Moeller <moeller0@gmx.de> writes:

> Hi Toke,
>
>> On Nov 20, 2016, at 12:17, Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>> 
>> Sebastian Moeller <moeller0@gmx.de> writes:
>> 
>>> Hi Dave,
>>> 
>>>> On Nov 19, 2016, at 19:10, Dave Taht <dave.taht@gmail.com> wrote:
>>>> 
>>>> While I have always encouraged people to "go right to the graphs", I
>>>> have generally
>>>> wanted a bit more text output to make email comms easier, and toke has
>>>> just added
>>>> some basic output stats to flent in git head.
>>> 
>>> 	Is that pushed to github yet? I tried a git pull but got nothing new. Testing with:
>>> date ; ping -c 10 netperf-eu.bufferbloat.net ; ./run-flent --ipv4 -l 60 -H netperf-eu.bufferbloat.net rrul_cs8 --remote-metadata=root@192.168.1.1 -p all_scaled -D . -t IPv4_SQM_LLA-simple-fq_codel-ETH_OH16_U095pct9545of10048K-D90pct46246of51385K_2_netperf-eu
>>> did not give any stats. So is the output generic or restricted to
>>> specific tests?
>> 
>> No, it only happens if you don't select another output format; in this
>> case a plot. You can select this the summary formatter explicitly (and
>> thus turn off plots) by passing '-f summary'. Works when loading a
>> previous data file as well…
>
> Ah, now git pull acyually got me something new and without a -p directive I also see the stats output, great! Now I actually do wonder how hard it would be to add
> a measure of variance, say the standard deviation or the standard error of the
> mean to the output (to qualify the average, which probably is the arithmetic
> mean, which might be worth noting in the header column). And finally for the
> latency probes, I believe maybe the 95th or 99th percentile would be closer to
> what we recommend people looking at? (I note that I typically start my flent
> runs with 10 un-contended ICMP echo requests from the command line to get a
> reasonable idea what the best case RTT actually is, a similar value could be
> extracted from the start of the flent run before the data streams have started?)
> I guess instead of writing emails I should actually look and write code… (maybe
> I find tie to look into that).

SummaryFormatter in formatters.py. Pretty straight forward :)

> Final questions why is this output mutually exclusive with plots?

Because internally Flent's notion of output is to format the data with a
Formatter class, only one of which can be active at a time. One of those
is the PlotFormatter that outputs plots, so if that is active no other
output is seen.

-Toke