An insert-heavy workload shows that the biggest bottleneck is the contention on the replication coordinator mutex between calls to getTerm() and calls to setMyLastAppliedOpTimeForward().

In 3.4, these same mutex acquisitions were there, so I'm not sure if this is a new issue. However, I do get a big boost in performance if I comment out the mutex acquisition for getTerm(), so I would like to pursue making this more efficient.