C100DBA Sharding Practice Question
During routine cluster maintenance, an administrator needs to remove an underperforming shard from a production MongoDB sharded cluster safely. What is the mandatory first step the administrator must execute?
⚠ Common exam trap
Candidates often assume they must manually stop the balancer or move data off the shard first. In reality, the removeShard command automates the entire migration process internally once triggered.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Run the removeShard command on the admin database via a mongos connection to initiate the automated chunk draining process.
Removing a shard safely begins with executing the removeShard command, which initiates the draining process. The cluster balancer automatically migrates all chunks residing on the target shard to other available shards in the cluster, ensuring no user data is lost before the node is decommissioned.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Run the removeShard command on the admin database via a mongos connection to initiate the automated chunk draining process.
Why this is correct
Run the removeShard command on the admin database via a mongos connection to initiate the automated chunk draining process. The removeShard command instructs the cluster balancer to begin migrating all data chunks off the specified shard onto remaining active shards in a controlled manner.
- ✗
Execute the dropDatabase command on every secondary member of the shard replica set to clear local storage blocks instantly.
Why it's wrong here
Execute the dropDatabase command on every secondary member of the shard replica set to clear local storage blocks instantly. Dropping databases directly on shard members causes catastrophic data loss and corrupts cluster metadata maintained by the config servers.
- ✗
Manually shut down all mongod processes associated with the target shard before notifying the config server replica set.
Why it's wrong here
Manually shut down all mongod processes associated with the target shard before notifying the config server replica set. Abruptly shutting down a shard without draining leaves stranded chunks and triggers critical cluster metadata synchronization errors.
- ✗
Run the reshardCollection command to merge all orphaned documents into a single backup file on the primary config server.
Why it's wrong here
Run the reshardCollection command to merge all orphaned documents into a single backup file on the primary config server. ReshardCollection is used to change an existing shard key, not to remove a physical shard from a cluster infrastructure.
About these practice questions
This C100DBA question is part of Courseiva's 222-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official MongoDB exam blueprint
This C100DBA practice question is part of Courseiva's free MongoDB certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the C100DBA exam.