C100DBA Replication Practice Question
Which THREE factors can significantly impact the time taken for a new primary election?
⚠ Common exam trap
Candidates often overlook network latency and heartbeat timeouts, incorrectly assuming replica set elections are instantaneous or solely dependent on hardware specs.
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
✓
The network latency between replica set members.
The speed of a failover is determined by how quickly nodes detect the primary is down and how quickly they can reach a consensus. Network latency between nodes, the heartbeat interval, and the number of nodes in the set are all critical. Optimizing these factors is necessary for maintaining a high-availability architecture that can recover from outages within the expected time window defined by SLAs.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The network latency between replica set members.
Why this is correct
Higher network latency increases the time required for heartbeat signals to travel between nodes. If heartbeats take longer to arrive, the remaining nodes will wait longer before declaring the primary unreachable, thereby increasing the total time elapsed before a new election is triggered and a new primary is established.
- ✗
The total number of documents in the largest collection.
Why it's wrong here
The election process is independent of the dataset size or the document count. It relies on the exchange of metadata and configuration information between members. While large datasets can affect initial sync time, they have no bearing on how quickly nodes can negotiate and elect a new primary.
- ✓
The heartbeat timeout setting (electionTimeoutMillis).
Why this is correct
This setting directly controls how long a secondary waits without receiving a heartbeat before it suspects the primary is offline and initiates an election. A smaller value results in faster failover, but it may also increase the risk of false positives caused by transient network spikes or congestion.
- ✗
The amount of free RAM available on the primary node.
Why it's wrong here
Memory availability on the primary does not influence election timing. The election is a protocol-level event managed by the set members. While a healthy primary node is essential for performance, the election mechanism itself is entirely decoupled from the hardware-level resource utilization of the nodes involved in the voting.
- ✓
The total number of voting members in the replica set.
Why this is correct
In a larger replica set, the consensus process requires more nodes to communicate and agree on the election outcome. Coordinating votes among a larger group naturally adds overhead to the election process, as the candidate must establish connectivity and verify status across a wider, more complex network topology.
About these practice questions
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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.