We create a new test suite called concurrency_replication_causal_consistency in SERVER-32883, which runs all the fsm workloads with causal consistency on a 5-node linear chained replica set.
Tests such as auth_create_role.js timed out due to very slow dropRole operations which are done with majority write concerns. We later figured out the slowness was caused by not notifying the oplog waiter immediately after advancing the lastApplied timestamp. So another secondary which syncs from the secondary would wait long time(~20s) for the notification that lastApplied has been advanced.