• with workload to insert into capped collection with MMAPv1, the secondary could not keep up
• the speed to drain oplog is slow with capped collection, this may cause performance test timeout for waiting for w:ALL (w:NUM_OF_NODES) write (2 hours)
• the repro step is same as SERVER-21646, except test this with MMAPv1
• this issue recently surfaced due to we added forceSyncOplog for some of the workload, thus triggered timeout.

for comparison, after fix for SERVER-21646, WR insert_capped operates at 12,230 ops, and MMAPv1 is doing 34,250 ops