BAARDA, Don wrote: > [...] > > If you're (also) interested in the maximum number of lines in > > use, a good way of doing so is to define: > > - an RRD with step time of one second, and a heartbeat of > 300. > > - an RRA with averages for 300 PDPs per CDP. > > - an RRA with maxima for 300 PDPs per CDP. > > > This is the solution I would prefer for accurate graphing of > "events", rather than "intervals". If you extend the heartbeat out to a day > or two, the only time you need to feed data to rrd is when the status > changes (provided the status changes at least every day or two). However, > it's probably a good idea to use a low-ish heartbeat and include periodic > updates as well as "status change events" incase you miss an event. The best > way to do this is use snmp for the periodic samples, and snmp-trap for the > "events".
So, you agree with me. I have one addition to this: If possible, use the time on the device and not the time on the monitoring box. This prevents delay (which is not nice but also not a big problem) and jitter (which can be a big problem). > > Everytime something changes in the line status, remember the number > > of lines. The *next* time something changes, or the next 5-minute > > boundary, you enter the remembered value (which will be valid from > > the previous update to the current one). > [...] > > This is the tricky bit. RRD with assumes a sample refers to the > previous interval between samples, not the next interval. This means at each > change in status, you need to tell rrd what it _was_, not what it now _is_. Don't forget the periodic update. First of all you need this when there is no change during a long time. You can *guess* that your heartbeat is long enough, or you can *make sure* it is by forcing an update every 5 minutes or so. This is also good for a second purpose: you don't want a long series of unknown at the end of your database while in fact you know that nothing changed and thus you *do* know the number of lines in use. cheers -- __________________________________________________________________ / [EMAIL PROTECTED] [EMAIL PROTECTED] \ | work private | | My employer is capable of speaking therefore I speak only for myself | +----------------------------------------------------------------------+ | Technical questions sent directly to me will be nuked. Use the list. | +----------------------------------------------------------------------+ | http://faq.mrtg.org/ | | http://rrdtool.eu.org --> tutorial | +----------------------------------------------------------------------+ -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
