Cloud Digital Leader Scaling with Google Cloud operations Practice Question
An SRE team is practicing 'chaos engineering' by simulating a zone-level failure in their staging environment. They find that their application does not automatically recover — traffic is not redirected and the service remains down. What architectural component is most likely missing?
⚠ Common exam trap
Candidates often confuse 'scaling up' (larger machine types or more replicas) with 'resilience through load balancing', failing to recognize that without a load balancer with health checks, no amount of capacity in surviving zones will automatically redirect traffic.
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
✓
A load balancer with health checks across multiple zones is most likely missing — without it, there is no mechanism to detect the zone failure and automatically redirect traffic to healthy instances in surviving zones
In a zone-level failure, traffic cannot be redirected to healthy instances in surviving zones without a load balancer that performs health checks across multiple zones. Google Cloud's external or internal load balancers (e.g., HTTP(S) Load Balancer, TCP/UDP Network Load Balancer) use health checks to detect unhealthy instances and automatically route traffic only to healthy backends. Without this component, the application has no mechanism to detect the zone failure and reroute traffic, leaving the service down.
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 application needs more replicas in the failing zone to survive the failure
Why it's wrong here
Simply increasing the replica count inside the already-failing zone cannot improve availability because when that zone goes down, every instance hosted there becomes unreachable at the same time; the outage is at the zone level, not at the instance level. Spreading replicas across multiple zones is a necessary prerequisite for zone-failure resilience, but the actual mechanism that detects a zone outage and shifts traffic is a cross-zone load balancer with health checks. Without that balancer, even extra replicas elsewhere will not benefit clients who currently connect directly to the dead zone.
- ✓
A load balancer with health checks across multiple zones is most likely missing — without it, there is no mechanism to detect the zone failure and automatically redirect traffic to healthy instances in surviving zones
Why this is correct
The load balancer is the key component. It must be configured with backend instances in multiple zones and health checks enabled. When the health check detects that zone A instances are unhealthy, it automatically removes them from the rotation and sends all traffic to healthy instances in zones B and C. Without the load balancer, clients connect directly to zone A and have no fallback.
- ✗
The application needs a larger machine type to handle the full traffic load without the failed zone's capacity
Why it's wrong here
Larger machines in the remaining zones may be needed to handle full traffic, but this is a capacity concern, not the mechanism for automatic traffic redirection. The load balancer is the missing routing and detection component.
- ✗
Cloud Monitoring alerts need to be configured to notify the team when a zone fails, enabling manual traffic redirection
Why it's wrong here
Configuring Cloud Monitoring alerts and relying on manual redirection introduces human latency, which typically delays failover by minutes and violates the fast, automatic recovery expected during a zone outage. A load balancer with health checks continuously probes each backend instance and automatically removes unhealthy ones from the pool within seconds, then routes all new connections to surviving zones without operator intervention. Alerts are useful for triggering post-incident investigation, but they cannot replace the self-healing, programmatic traffic management that a load balancer provides.
Go deeper
Related to this question
Learn chapter
Cloud Digital Transformation
Key term
TCP
TCP is a connection-oriented transport layer protocol that ensures reliable, ordered, and error-checked delivery of data between applications over IP networks.
Key term
Network Load Balancer
A Network Load Balancer is a cloud service that automatically distributes incoming network traffic across multiple servers to ensure applications remain fast, available, and secure.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This GCDL practice question is part of Courseiva's free Google Cloud 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 GCDL exam.