Hello C* community, I have been experimenting a bit with my lab node. I am assuming the following as observing the progress of metrics over time:
1. EstimatedPartitionSizeHistogram metric derives from READ operations. Cassandra reports values to this metric as it serves Read queries. 2. <Min,Max,Mean>PartitionSize derives from the Compaction activities. Cassandra reports values to this metric as it performs the compaction of sstables. I am not sure whether those assumptions are valid but at least provide a good explanation to the progress of the stats observed. Thanks a lot and CU on the next topic. BR MK From: Michail Kotsiouros via user <user@cassandra.apache.org> Sent: Thursday, May 11, 2023 14:08 To: user@cassandra.apache.org Subject: RE: Questions about high read latency and related metrics Hello Erick, No Max/Min/Mean vs Histogram difference is clear. What confuses me is the description of those metrics: Size of the <largest,smallest,average> compacted partition (in bytes). Vs estimated partition size. I am after what is measured by each metric. To be more specific: What metric should be consider when we want to see the partition size over time? Does this “compacted partition” means that only the partitions which have undergone a compaction in the respective sstables are taken into account for <Min,Max,Mean>PartitionSize metrics? What “estimated” means in the EstimatedPartitionSizeHistogram metric? Excuse me if those questions sound trivial. BR MK From: Erick Ramirez <erickramire...@apache.org<mailto:erickramire...@apache.org>> Sent: Thursday, May 11, 2023 13:16 To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>; Michail Kotsiouros <michail.kotsiou...@ericsson.com<mailto:michail.kotsiou...@ericsson.com>> Subject: Re: Questions about high read latency and related metrics Is it the concept of histograms that's not clear? Something else?
