Hi, we are running a 1.1.6 (datastax) test cluster with 6 nodes. After the recent 1.2 release we have set up a second cluster - also having 6 nodes running 1.2 (datastax).
They are now running in parallel. We noticed an increase in the number of writes in our monitoring tool (Datadog). The tool is using the write count statistic of nodetool cfstats. So we ran nodetool cfstats on one node in each cluster. To get an initial write count. Then we ran it again after 60 sec. It looks like the 1.2 received about twice the amount of writes. The way our application is designed is that the writes are idempotent, so we don't see a size increase. Were there any changes in between 1.1.6 > 1.2 that could explain this behavior? I know that 1.2 has the concept of virtual nodes, to spread out the data more evenly. So if the "write count" value was actually the sum of all writes to all nodes in the, this increase would make sense. Reik ps. the clusters are not 100% identical. i.e. since bloom filters are now off-heap, we changed settings for heap size and memtables. Cluster 1.1.6: heap 8G, memtables 1/3 of heap. Cluster 1.2.0: heap 4G, memtables 2G. Not sure it can have an impact on the problem.
