On Wed, Aug 22, 2007 at 12:54:00PM +0400, Oleg Derevenetz wrote: > But is there any way to say rrdupdate that there is no wrap ? For example, if > I getting counters from network device interface, and > I really know that device was rebooted recently, is there any way to say > rrdupdate that only THIS counter value should not be > wrapped, but all subsequent values should be wrapped when necessary ?
What do you know? 1: you know the most recent update (this is already in RRDtool) 2: you know a reboot has occured 3: you know the counter starts at zero when a reboot occurs In step 2, you probably also know (or can know) the exact time when this reboot occured. What do you NOT know? 1: the interval between the most recent update and the reboot 2: the countervalue at time of reboot 3: as a result of 1 and 2: the resulting rate is unknown if you do not know the exact time of the reboot: 4: the interval between the reboot and the first regular update 5: as a result, you can't compute a rate and neither can RRDtool So, there are two distinct cases: a) you do know the exact reboot time b) you don't Some variables to be able to talk: n countervalue at first poll after reboot Tf time of first poll after reboot Tl time of last poll before reboot Tr time of reset In case (a): Update your database at time Tr-1 with value U Update your database at time Tr with value 0 Update your database at time Tf with value n Result: Time Tl to Tr has an unknown rate. Time Tr to Tf has a known rate of n/Tf In case (b): Update your database at time Tf-1 with value U Update your database at time Tf with value n Result: Time Tl to Tr has an unknown rate. Time Tr to Tf has an unknown rate as well. HTH -- Alex van den Bogaerdt http://www.vandenbogaerdt.nl/rrdtool/ _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
