Whilst debugging our CollectD and Graphite setup, I found that CollectD was generating hundreds of repeated errors.
<br /> Jun 13 17:11:14 hmon collectd[15336]: rrdtool plugin: rrd_update_r (/var/lib/collectd/rrd/hmon/processes/ps_state-running.rrd) failed: /var/lib/collectd/rrd/hmon/processes/ps_state-running.rrd: illegal attempt to update using time 1371136272 when last update time is 1371136272 (minimum one second step)<br /> Jun 13 17:11:14 hmon collectd[15336]: rrdtool plugin: rrd_update_r (/var/lib/collectd/rrd/hmon/processes/ps_state-sleeping.rrd) failed: /var/lib/collectd/rrd/hmon/processes/ps_state-sleeping.rrd: illegal attempt to update using time 1371136272 when last update time is 1371136272 (minimum one second step)<br /> Jun 13 17:11:14 hmon collectd[15336]: rrdtool plugin: rrd_update_r (/var/lib/collectd/rrd/hmon/processes/ps_state-zombies.rrd) failed: /var/lib/collectd/rrd/hmon/processes/ps_state-zombies.rrd: illegal attempt to update using time 1371136272 when last update time is 1371136272 (minimum one second step)<br />