The _shardsvrMovePrimaryExitCriticalSection command is used in the context of the movePrimary command by the donor to ask the recipient to exit its critical section.

There are situation where the command reply is not received by the donor, although the critical section was actually exited. The critical section (on the recipient) could be re-entered by another operation, and the second call attempt from the donor could fail since the passed reason differs from the one of the entered critical section.

One goal of this ticket is make the _shardsvrMovePrimaryExitCriticalSection command idempotent (in the end the passed critical section is actually exited).