Yep. #2 is kind of a hush-hush way of them fixing a bug that can take a lock on a collection during a chunk merge and fail to release it, resulting in writes to

Yep. #2 is kind of a hush-hush way of them fixing a bug that can take a lock on a collection during a chunk merge and fail to release it, resulting in writes to primaries to stop until they are kill -9'd.