After ~24 hours or so, I am finding that performance gradually degrades.

• Primary: 2.8.0rc1 WT
• Secondaries: 2.8.0rc1 MMAPv1

Please see attached MMS Screenshot. The displayed range starts shortly after a full system restart. Note that queues increase as well as replication lag on the secondaries. Also attach opcounters, from which you can at least crudely see that the application load is consistent.

I do not see this type of behavior when the primary is MMAPv1.