Exam C100DBA Topic 5 Question 110 Discussion

MongoDB supports a clean server shutdown through the shutdown administrative command and through the mongosh helper db.shutdownServer(). Option A uses db.adminCommand({ shutdown: 1 }), which executes the shutdown command against the admin database and requests an orderly termination of the server process.
Option D explicitly switches to the admin database and calls db.shutdownServer(), the documented shell helper that wraps the same administrative behavior. Option B uses killOp, which terminates a specific database operation identified by an operation ID; port 27017 is not an operation ID and killing an operation is not equivalent to shutting down mongod. Option C uses killAllSessions, which ends logical sessions but leaves the server process running. A controlled shutdown is preferred over abruptly terminating the process because MongoDB can close resources and complete its shutdown procedures cleanly. In replica-set deployments, administrators should also consider whether the member is primary and whether a planned step- down is appropriate before maintenance. Among the commands shown, A and D are the two valid mongosh- based shutdown mechanisms.
Study Guide reference/topic:MongoDB Architecture and Core Operations - clean server shutdown, admin commands, and db.shutdownServer().