280 sec: 865658 operations; 2661.5 current ops/sec; [INSERT
AverageLatency(us)=3640.16]
290 sec: 865658 operations; 0 current ops/sec;
It also may indicate that C* trying to finished active tasks and your write
requests have been
in the queue all 10 sec. Try to monitor C* doing*$watch nodetool
ParNew GC (used by default in cassandra) uses 'stop-the-world' algorithm,
which means your application has to be stopped to do gc.
You can run jstat command to monitor gc activity and check if your write
performance is related to GC, eg:
$ jstat -gc 1s
But it shouldn't drop throughtput to 0 ops/s.