Hi David and Martin, I suppose the network code is still the code I wrote, so there are two problems I know of: 1. yes there is a problem with owerflows 2. the shown network traffic is the sum of all network interfaces including local loopback devices (lo0...).
Both Problems could lead to astonishing data transfer rate in ganglia. Sorry I had promised to fix the problems, but there was to much other work ... Best regards Andreas > Date: Thu, 29 Mar 2007 08:21:38 -0700 (PDT) > From: Martin Knoblauch <[EMAIL PROTECTED]> > Subject: Re: [Ganglia-general] Help! I have a petabyte/s network > To: David Wong <[EMAIL PROTECTED]>, [EMAIL PROTECTED], > [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=iso-8859-1 > > David, > > good catch. I will have to look at it for a bit. > > Cheers > Martin > --- David Wong <[EMAIL PROTECTED]> wrote: > >> > I don't write much code nowadays, so I'm going to need a lot of help >> > with this. >> > >> > I dug through the ganglia code and I found this interesting tidbit in >> > libmetrics/aix/metrics.c which may be indicative of the problem. >> > >> > There's an assignment from cur_ninfo.ibytes to cur_net_stat.ibytes, >> > but >> > the types of the two variables are different. >> > >> > net_stat::ibytes is a double: >> > >> > struct net_stat{ >> > double ipackets; >> > double opackets; >> > double ibytes; >> > double obytes; >> > } cur_net_stat; >> > >> > and we have *ninfo declared here: >> > >> > perfstat_netinterface_total_t ninfo[2],*last_ninfo, *cur_ninfo ; >> > >> > libperfstat.h has perfstat_netinterface_total_t::ibytes as >> > u_longlong_t. >> > >> > Does this code try to do what I think it is doing, i.e. assign an >> > unsigned 64 bit integer to a signed 64bit integer? >> > >> > I'm willing to test the code if someone who's more adept at coding >> > and >> > building will take on the challenge. >> > >> > It looks to me that the type mismatch will have to fixed in a few >> > places, such as CALC_NETSTAT, and we'll have to add an unsigned long >> > long to g_val_t too. Those are the ones I can see so far. >> > >> > David Wong >> > Senior Systems Engineer >> > Management Dynamics, Inc. >> > Phone: 201-804-6127 >> > [EMAIL PROTECTED] >> > >> > -----Original Message----- >> > From: Martin Knoblauch [mailto:[EMAIL PROTECTED] >> > Sent: Wednesday, March 28, 2007 12:00 PM >> > To: David Wong; [email protected] >> > Subject: Re: [Ganglia-general] Help! I have a petabyte/s network >> > >> > David, >> > >> > as far as I remember, the AIX metrics code had an >> > overflow/wrap-around >> > problem prior to 3.0.4. Maybe the fixes are not thorough enough. >> > >> > The packets/sec are of course less affected. >> > >> > Cheers >> > Martin -- Dr. Andreas Schoenfeld | Dr. Andreas Schoenfeld | Technische Universitaet Darmstadt | Technische Universitaet Darmstadt Hochschulrechenzentrum (HRZ)| University Computing Centre | Petersenstrasse 30 | Petersenstrasse 30 64287 Darmstadt | 64287 Darmstadt | Germany | Tel. 06151-16 5608 | Tel. +49 (0) 6151-16 5608 e-mail: [EMAIL PROTECTED]
