If a getMore command tries to use a cursor while a releaseMemory is using it, the getMore command will fail with error ErrorCodes::CursorInUse . This does not provide a good user experience.

When a command tries to pin a cursor, there is the error CursorInUse If a getMore command gets this error maybe it can check if it is in use by a releaseMemory command, wait (with a timeout? in a condition?) and retry.