I'm currently using 1-node cluster with DataStax Opscenter 5.2.1 (Cassandra 2.2.3) installed on Windows.
There is not too much data is sent to the cluster, and here is the graph (last 20 minutes) of write requests that I can see in Opscenter. The graph looks normal and expected for me: write_requests(20min)
However, when I've switched the data range to last 1 hour, as turns out there were much more write requests (according to cluste(max) line): write_requests(1h)
I'm confused, could someone clarify what cluster(max) means in my case? Why these values are so big in comparison with cluster(total) or cluster(min)?
The first graph (20 minute) uses an average. The 1h graph will have 3 lines - min per sample, average, and max per sample.
What you're likely seeing is that something (perhaps opscenter itself) is doing a flood of writes, about 700/second for a few seconds, and on the 20 minute graph it gets averaged out, but with the min/max lines, you'll see the outliers.
