On 24 April 2015 at 18:32, Sergey <[email protected]> wrote: > > nothing new: > > [pid 10586] poll([{fd=3, events=POLLIN|POLLPRI}], 1, 500) = 1 ([{fd=3, > revents=POLLIN}]) > [pid 10586] read(3, "update /var/lib/collectd/rrd/hostname/cpu-0/cpu-user.rrd > 1429861837:34507652\n", 8192) = 87 > [pid 10586] write(3, "-1 illegal attempt to update using time > 1429861837.000000 when last update time is 1429861847.000000 (minimum one > second step)\n", 127) = 127 > > Attempt to write timestamp 1429861837 after 1429861847.
The possibilities that come to mind here are: - rrdcached is doing an out-of-order update to the RRD file due to a bug - collectd is passing the values to rrdcached with out of order timestamps - collectd is receiving the data out of order from the collectd agent To determine if it's an rrdcached bug, try connecting over the rrdcached socket and issuing a bunch of UPDATE commands, then issue a FLUSH, then check if the RRD files on disk have been updated. The rrdcached man page has extensive documentation that covers the protocol syntax to do this. To determine if collectd is passing out of order values to rrdcached, kill rrdcached, and use something like nc to listen at the same socket path, and grep to see if the timestamps are monotonically increasing. To determine if collectd is receiving the data out of order, use tshark to capture the traffic, and use the display filters to show a single sample metric, and check if the timestamps are monotonically increasing. Out of those three possibilities, my bet would be on collectd receiving the data from agents out of order. Cheers, Lindsay _______________________________________________ collectd mailing list [email protected] http://mailman.verplant.org/listinfo/collectd
