The ShardRegistry is the only component living on the Grid that requires an additional initializing procedure after its creation. My claim is that this initializing procedure can be perform directly in the constructor. This will allow to simplify the logic of the ShardRegistry because it will eliminate one of its possible states:

1. Created
2. Initialized
3. Up
4. Shutdown
5. Destructed

The shardRegistry creation happen respectively:

• Mongod
• Mongos