Well thanks, but basically darkstat has zero configuration. It just outputs the total download traffic per host IP. And I believe that's the same thing returned by that SQL query I posted. Since both apps are running on the same server, I guess they should pretty much be equivalent. Please do let me know if you think there are specific tests I can do to ensure equivalency
I will in the mean time, try the previosuly suggested test of downloading a fixed file size Thanks and best regards On Tue, Jun 10, 2008 at 12:59 PM, alex <[EMAIL PROTECTED]> wrote: > Hello Ahmed, > I only want to add that you must be strong ensure that you compare > same flows of data. It is seem obviously but you can easy miss something > in setting of both programs and compare hasn't any sense. > > Alex > > > > Hi Ahmed, > > > > On Tue, 10 Jun 2008, Ahmed Kamal wrote: > > > >> I have setup pmacct with your help, and it's been running like a champ. > I > >> have also installed darkstat for comparison. I am seeing a big error > >>(around > >> 30%) between the 2 tools! > > ... > >> Here's what I am seeing: > >> > >> IP START END DELTA > >> DARKSTAT(bytes) > >> 81.10.100.42 7607.7053 9477.4200 1869.7147 1,397,584,555 > >> 81.10.100.73 3603.2834 4716.6248 1113.3414 810,169,491 > >> 81.10.100.37 3540.3343 5698.6758 2158.3415 1,573,900,631 > >> 81.10.100.199 3444.3568 4358.3895 914.0327 575,124,842 > >> 81.10.100.75 2951.8349 3697.5900 745.7551 556,560,149 > >> 81.10.100.30 2770.9552 3807.6038 1036.6486 715,830,077 > >> 81.10.100.46 2698.5764 3987.1379 1288.5615 856,582,079 > >> 81.10.100.44 1982.1858 2381.7297 399.5439 296,992,631 > >> 81.10.100.71 1880.2033 2522.7183 642.5150 548,180,038 > >> 81.10.100.201 1300.2739 2040.0713 739.7974 411,031,858 > >> > >> Those are the top 10 BW users. All measurements are in MB (from SQL > >>query), > >> darkstat data is in bytes. As you can see, the first line it's 1.9GB vs > >> 1.4GB and so on ... > >> > >> Any ideas how to track such errors ? > > > > My first suspicion would be that Darkstat is reporting bytes transferred > > (TCP data) rather than total size of packets. You can confirm this with > > some simple tests. E.g. create a file of exactly 1MB on a remote web > > server and download it through your pmacct/darkstat box. If darkstat > > reports that the amount downloaded is just over 1MB (e.g. 1.001 MB) then > > it's reporting TCP data. > > > > pmacct will always report packet sizes (IP data) and therefore is likely > > to report more bytes downloaded. Given that the TCP overhead is about 40 > > bytes per 1500 byte packet, i.e. about 2.6%, I'd expect it to report > about > > 1.027 MB in this case. > > > > The overhead will be much higher for smaller packets which may explain > > your observed 30% discrepancy. If so, this is arguably a bug (or > > limitation) of darkstat rather than pmacct. > > > > Please let us know what you discover. > > > > Cheers, Chris. > > > > ------ > Недвижимость - по-прежнему самое перспективное вложение денег! > http://www.tmk.by Тел. (029) 628 28 28, (017) 507 61 37 > > > > _______________________________________________ > pmacct-discussion mailing list > http://www.pmacct.net/#mailinglists >
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