We need to handle waitForDelete flags from migrations, and cleanupOrphaned commands, that won't continue until the range is deleted. Therefore we'll create a Notification object to return to notify when the range has been removed. A future addition would be to put the range to clean at the head of the a rangesToClean vector of some sort so that it is the next range to be deleted, but we're not going to worry about that right now.

Suppose ranges to clean is this right now:

map<BSONObj, Range> rangesToClean

we're changing it to

map<BSONObj, RangeDescriptor> rangesToClean

RangeDescriptor has

• Range
• Notification

The Notification will need to be threaded back to the caller somehow. We'll look at the MetadataManager code and figure this out when it is more stable