our gmetad boxes (2 of them) with 12 data sources, 6 of which are
gmetad and 6 gmonds, are spamming syslog like mad with the following

Sep  6 06:33:32 localhost.localdomain /usr/sbin/gmetad[2526]:
RRD_update (/var/lib/ganglia/rrds/...metric.rrd): illegal attempt to
update using time 1252244010 when last update time is 1252244010
(minimum one second step)

This happens for both metrics and summary graphs.

Looking at the hosts every appear to be fine to me, and ntp is running
everywhere and in sync.

Looking at the code instead both gmetad/gmetad.c and
gmetad/data_thread.c have a possibly suspicious call to sleep:

in gmetad.c:417
         sleep_time = 10 + ((30-10)*1.0) * rand()/(RAND_MAX + 1.0);

in data_thread.c:193
         sleep_time = (d->step - 5) + (10 * (rand()/(float)RAND_MAX))
- (end.tv_sec - start.tv_sec);
         if( sleep_time > 0 )

two observation:
- based on man 3 sleep, if any signal is sent to gmetad, the sleep
interval can be 0
- end.tv_sec - start.tv_sec could compute to a considerably high
number that along with a short step could result in a sleep_time < =



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