Hi Dan, yes you did find a number of corner cases here .. the problem realy is what algorithm to use for the proper scaling. At the moment I only look at the median and then add some space on top of it. But maybe we should look at some other property ...
look for the find_max function in Smokeping.pm to see what is presently being done ... as for the logarithm stuff, this is a user contributed feature which is not well integrated. I do all my work without it enabled, I guess it would need rather different settings to work well. For the upcomming ajax version of smoekping I imagine to have graph properties configurable interactively so that you can make a graph look right by hand once you have identified an interesting section. cheers tobi Today G.W. Haywood wrote: > Hello again Tobi, > > On Mon, 28 Apr 2008, G.W. Haywood wrote: > > > On Sat, 26 Apr 2008, Tobias Oetiker wrote: > > > G.W. Haywood wrote: > > > > > > > http://www.jubileegroup.co.uk/JOS/misc/scales_oddity.gif > > > > > > > > Maybe graphs should default to a logarithmic scale? > > > > > > The reason the 'spike' is lower in the last 10 day graph is that a > > > single pixle there represents more data than in the higher > > > resolution graphs ... the net result is, that the spike becomes > > > lower as it gets distributed across time ... > > > > With the result that the graphs give a very misleading impression of > > the data under certain circumstances. > > > > ... you've made some changes in the latest version ... I'll have > > a look at it before commenting further. > > The 'smoke' rising to the top of the graphs is an improvement. I'm > now using logarithmic graphs but I'm still having difficulties with > the scales. > > http://www.jubileegroup.co.uk/JOS/misc/WRT54GS4_logarithmic_graph.gif > http://www.jubileegroup.co.uk/JOS/misc/tornado_logarithmic_graph.gif > http://www.jubileegroup.co.uk/JOS/misc/webserver_logarithmic_graph.gif > > As you can see a minimum RTT on the logarithmic graphs of 100us gives > rather silly results if the typical RTT is 30us... > > The range selection algorithm seems not to take (much?) into account > deviations of RTT substantially above the norm. The results resemble > a hedgehog after mowing the lawn. Possibly the graph parameters need > to be individually configurable for each (probe,target) pair. FWIW my > preference would probably be for manual configuration, at least of the > graph range limits. My logic is that a particular network path will > typically have a 'normal' performance. Large excursions from normal > will be of most interest, while smaller fluctuations will tend to be > ignored. I'm thinking that I would be quite happy with a fixed upper > bound on the logarithmic graphs of ca. one second, and a lower bound > which varies by factors of say 10e+0.5 from 10us to 100ms. Obviously > anyone making ssh connections over a satellite link would want to say > something about that. :) I'll tweak the code and see how it goes. > > Having griped more than enough about relatively easily fixed things > like the graph scales I think I ought to thank you for all the hard > work you've done to make SmokePing such a tremendously useful tool! > > -- > > 73, > Ged. > > _______________________________________________ > smokeping-users mailing list > [email protected] > https://lists.oetiker.ch/cgi-bin/listinfo/smokeping-users > > -- Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten http://it.oetiker.ch [EMAIL PROTECTED] ++41 62 213 9902 _______________________________________________ smokeping-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/smokeping-users
