I can't say for sure, as I don't know the code, but it might have to do with the interval at which the metrics are reported vs the time resolution of each interval on the x axis. For example, if each interval is 30 seconds and you report data every 60 seconds, then every other value on the x axis would be zero. I don't think the monitor does any interpolation for missing values.
I am trying to figure out something that I always notice across our Accumulo instantiations. It’s concerning the Scan (Entries/s) graph in the attached screenshot from the Accumulo monitor.
For the given time period there is only steady heartbeat activity. For every hearbeat received, a relatively small set of Accumulo records are scanned and a couple of those rows are updated. Since the number of rows scanned is constant, the saw-tooth shape doesn’t make sense.
My initial reaction was that the compactions might be affecting the number of scans, but as you can see the ‘notch’ in the saw-tooth pattern doesn’t line up with when the minor or major compaction occur.
Can anyone shade some light please? Thank you.
