sorry but I have to get back to this, I'm really getting crazy with these spikes in my graphs.
Is there a way to DISABLE that mrtg checks for a counter overflow ? either globally or (better) per device, because I'd rather loose a few bytes sometimes when the counters do really overflow than having 100 spikes per week in my graphs. If a counter overflows MRTG should simply calc the value from zero.. I don't want to play around with the source, if there's no such config-option, which obviously according to the docs isn't, I'm sure then commenting out a few lines would help ;) anybody can tell me which ? I didn't manage to find out from the changelog in which version this "overflowed-counters" feature was implemented. I'd go back to an older version rather than having these spikes anymore.. Michael -----Original Message----- From: Michael Markstaller Sent: Thursday, April 24, 2003 10:03 PM To: (Verstrooid) Profke; Makai József; MRTG Mailing List Subject: [mrtg] Re: Spike after rebooting routers Hi, thanks for the detailed explanation, the "overflow" that mrtg thinks happened is what I already thought the reason for these spikes is.. Maybe I should have stated that more clearly, also, for sure I can make the spike smaller with setting maxbytes, absmax etc, but all of this doesn't solve the problem at the root ;-) I have currently about 80 hosts and 900 targets, configs are generated 90% automatically, tuning maxbytes values manually etc. is quite impossible. The maxbytes determined by reading ifSpeed is a very good thing I don't want to break up with as it affects several other things like percentages etc. After cleaning spikes for some hours today with this horrible killspike.pl I can imagine a possible solution but my perl know-how is far away from being able to realize/change this in mrtg: - Look on sysuptime, compare with the last timestamp in the .rrd and if it's lower than the difference, don't expect the counter wrapped and count the value received from zero. I cannot imagine this wasn't implemented or at least discussed yet but I found nothing in the lists so far.. Michael -----Original Message----- From: (Verstrooid) Profke [mailto:[EMAIL PROTECTED] Sent: Thursday, April 24, 2003 5:54 PM To: Makai József; Michael Markstaller; MRTG Mailing List Subject: Re: [mrtg] Re: Spike after rebooting routers maybe you can minimize the problem by setting a lower maxbytes value for that interface. any values higher than maxbytes are discarded because they are considered false. that way you should never get spikes higher then maxbytes. ----- Original Message ----- From: "Makai József" <[EMAIL PROTECTED]> To: "Michael Markstaller" <[EMAIL PROTECTED]>; "MRTG Mailing List" <[EMAIL PROTECTED]> Sent: Thursday, April 24, 2003 2:50 PM Subject: [mrtg] Re: Spike after rebooting routers > Hi Michael, > > This phenomenon is absolutely normal. > > In the router there are counters, and the mrtg checks the values in every 5 > minutes. > > After reading out the values the counters continues counting without zeroing > their values. > > If the next readout is higher, mrtg calculates the normal difference between > the two values, and stores it. > > If the next readout is lower then the previous one, that means that the > counter reached the 32 or 64 bit limit and continues counting from zero. > > In this case (the current value of a counter is lower then the previous one) > mrtg takes into consideration the overflow of the counters. > > (mrtg can calculate only with one overflow, so if you wanted to increase the > default 5 minutes interval, you must take this into consideration!) > > After a reboot the counters are reset, and the calculated values are > practically never real values. Either lower or higher due to the above > mentioned. (The spikes, what you find strange.) > > I hope this helps, > > Jozsef > > > > Hi there, > > > > I have a strange problem running MRTG against several cisco routers: > > when doing a IOS-update (or only reload) I sometimes get high > > spikes in *some* interface graphs. > > The ifIndex doesn't change and everything works fine besides > > from that, we're also talkking about upgrading minor > > release-versions without any noticeable other change in SNMP > > on the router. After the spike everything works fine again; > > It's quite annoying because it messes up the graphs' scale > > und my traffic totals, and fixing the spikes in the RRDs is > > also a time consuming task.. > > Is there any known workaround out there to prevent this > > (besides from setting AbsMax lower), either manual in advance > > to a (scheduled) reload/upgrade or preferably something > > generic in mrtg-config (might using snmpv2c help) ? > > another question: is there any other tool like killspike.pl > > which allows me to specify the time-period or somthing > > similar) where I want to kill spikes ? > > > > some of my config: mrtg-2.9.29 / RRDtool 1.0.41 on Red Hat Linux 7.3 > > > > > > thanks > > > > Michael > > -- > Unsubscribe mailto:[EMAIL PROTECTED] > Archive http://www.ee.ethz.ch/~slist/mrtg > FAQ http://faq.mrtg.org Homepage http://www.mrtg.org > WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi > > -- Unsubscribe mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/mrtg FAQ http://faq.mrtg.org Homepage http://www.mrtg.org WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi -- Unsubscribe mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/mrtg FAQ http://faq.mrtg.org Homepage http://www.mrtg.org WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
