We are averaging almost 600ms collection time for young generation, with occasional spikes of over 1s. These collection times might translate to increased request latency, or reduced throughput; They should be investigated, and a plan to lower them formed (including a move back to CMS).
Additionally, some effort should be made to determine if adequate performance can be obtained using a smaller heap size (current size: 16GB).
- https://issues.apache.org/jira/browse/CASSANDRA-7486 (G1GC as a default in 3.0)
- https://gist.github.com/tobert/ea9328e4873441c7fc34 (performance results)