Google PCA Ensure solution and operations reliability Practice Test 3 — 15 Questions

Question 1

An organization wants to define an SLO for their API hosted on Cloud Endpoints. Which metric should they use as a Service Level Indicator (SLI) for availability?

Accepted Answer

Ratio of HTTP 200 responses to total requests. For an availability SLO, the SLI must measure the proportion of successful requests. In Cloud Endpoints, availability is defined as the ratio of successful (HTTP 200) responses to total requests, as this directly reflects whether the API is functioning correctly. Option C is correct because it captures the fraction of requests that completed without error, which is the standard definition of availability in service-level monitoring.

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Number of HTTP 5xx errors

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Request latency at the 99th percentile

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CPU utilization of backend instances

Question 2

A company uses Cloud Armor to protect their HTTP Load Balancer from DDoS attacks. During a traffic spike from a legitimate source, legitimate requests are being blocked. How should they tune the security policy to minimize false positives?

Accepted Answer

Enable adaptive protection with machine learning. Option C is correct because enabling adaptive protection uses machine learning to distinguish between legitimate and malicious traffic, automatically adjusting rules. Increasing rate limiting threshold may help but is static. Whitelisting IPs is not scalable. Disabling WAF rules removes protection entirely.

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Increase the rate limiting threshold

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Disable the Web Application Firewall (WAF) rules

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Use the JSON Web Token (JWT) authentication to filter requests

Question 3

A developer wants to monitor a custom application metric from their application running on GKE. What should they use?

Accepted Answer

Cloud Monitoring custom metrics API. Cloud Monitoring custom metrics API (option D) is the correct choice because it allows a developer to push custom application-specific metrics (e.g., request latency, queue depth) from a GKE pod using the `custom.googleapis.com` metric domain. This integrates directly with Cloud Monitoring for alerting and dashboards, whereas Cloud Logging is for log data, not metrics.

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Cloud Logging

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Cloud Trace

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Cloud Debugger

Question 4

After a data corruption incident, a company needs to restore their Cloud SQL for PostgreSQL instance from a backup. What is the correct procedure to minimize downtime?

Accepted Answer

Restore the backup directly to the existing Cloud SQL instance. Restoring a backup directly to the existing Cloud SQL instance is the fastest method to minimize downtime because it overwrites the current data in-place without requiring DNS propagation, connection string changes, or reconfiguration of applications. Cloud SQL supports in-place restore from automated or on-demand backups, which typically completes within minutes for most instance sizes, as the operation leverages the underlying storage layer to apply the backup snapshot directly to the existing persistent disk.

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Create a new instance from the backup, then rename and delete the old instance

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Use point-in-time recovery to restore to a time before corruption

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Export the backup to Cloud Storage and import into the existing instance

Question 5

A company runs a stateful application on Compute Engine with persistent disks. They want to ensure data durability across a zone failure. What is the best approach?

Accepted Answer

Use regional persistent disks. Regional persistent disks (RPDs) synchronously replicate data between two zones in the same region, providing an RPO of zero and automatic failover without application-level changes. This ensures data durability across a zone failure while maintaining consistent performance and low latency.

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Replicate data at application level to another instance in a different zone

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Use Google Cloud NetApp Volumes with replication

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Take regular snapshots of the persistent disks and store them in a multiregional bucket

Question 6

A company wants to improve the reliability of their microservices architecture on Google Cloud. Which TWO practices should they implement? (Choose 2)

Accepted Answer

Implement retry with exponential backoff. B is correct because implementing retry with exponential backoff allows transient failures (e.g., network timeouts, temporary service unavailability) to be handled gracefully by automatically retrying the request after increasing delays, reducing load on the recovering service. This pattern is essential in microservices on Google Cloud to improve reliability without overwhelming downstream dependencies.

Answer

Design with a single point of failure for simplicity

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Use synchronous communication between all services

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Disable health checks to reduce latency

Question 7

A team is designing a disaster recovery (DR) plan for a critical application. Which THREE components are essential for a robust DR plan? (Choose 3)

Accepted Answer

Failover procedures and runbooks. Failover procedures and runbooks (A) are essential because they provide step-by-step instructions for executing a controlled transition to the secondary site, ensuring minimal downtime and consistent recovery actions. Without documented runbooks, teams risk misconfigurations during a disaster, which can extend recovery time objectives (RTO) beyond acceptable limits.

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A single-region deployment for consistency

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Load testing to validate performance

Question 8

A company wants to monitor the health of their Cloud Run services. Which THREE metrics should they use to define a comprehensive health SLI? (Choose 3)

Accepted Answer

Latency (e.g., p99 response time). Latency (p99 response time) is a critical metric for Cloud Run because it measures the end-to-end request processing time, directly reflecting user experience. In a serverless environment, high latency can indicate cold starts, insufficient concurrency, or downstream service bottlenecks, making it essential for a comprehensive health SLI.

Answer

CPU utilization

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Instance count

Question 9

A company is deploying a critical application on Compute Engine with an HTTP load balancer. They want to ensure that if an instance health check fails, traffic is automatically rerouted to healthy instances. Which configuration should they implement?

Accepted Answer

Use an HTTP(S) load balancer with a backend service configured with a health check and enable connection draining.. Option A is correct because an HTTP(S) load balancer with a backend service configured with a health check automatically monitors instance health and reroutes traffic away from unhealthy instances. Enabling connection draining ensures that in-flight requests to an unhealthy instance are given time to complete before the instance is removed from the load balancing pool, preventing disruption to active sessions.

Answer

Use an internal load balancer with a backend service configured with a health check.

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Use a network load balancer with a health check configured on the target pool.

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Use an HTTP(S) load balancer with a backend service configured with a health check and enable session affinity.

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Use a TCP proxy load balancer with a backend service configured with a health check.

Question 10

A financial services company runs a stateful backend service on Google Kubernetes Engine (GKE) using StatefulSets with Persistent Volumes. They observe that after a node failure, the pod is rescheduled on a different node but the Persistent Volume cannot be attached because it is still "released" and not "available". What is the most likely cause and solution?

Accepted Answer

The PersistentVolume has retain policy "Retain"; manually delete and recreate the volume.. Option A is correct because when a PersistentVolume (PV) has a reclaim policy of 'Retain', after the PersistentVolumeClaim (PVC) is deleted, the PV enters a 'Released' state and is not automatically recycled for reuse. The underlying storage resource (e.g., a Compute Engine persistent disk) still exists but the PV cannot be re-attached until an administrator manually deletes the PV and recreates it, or edits the PV to remove the claim reference. This explains why the pod rescheduled on a new node cannot attach the volume.

Answer

The PersistentVolume has reclaim policy "Recycle"; it is not supported in GKE.

Answer

The PersistentVolumeClaim was not created with the correct storage class; recreate with reclaim policy "Delete".

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The PersistentVolumeClaim's access mode is ReadWriteOnce, which prevents attachment to a new node; change to ReadWriteMany.

Answer

The PersistentVolume has reclaim policy "Retain" and the previous pod's volume attachment is not cleared; use a StatefulSet with volumeClaimTemplates and reclaim policy "Delete".

Question 11

A startup runs a web application on App Engine standard environment. They want to ensure the application can handle sudden traffic spikes without manual intervention. Which App Engine feature should they configure?

Accepted Answer

Automatic scaling with a maximum number of idle instances.. Option E is correct because App Engine's automatic scaling with a maximum number of idle instances is designed to handle sudden traffic spikes by dynamically creating and removing instances based on request load. This configuration allows the application to scale up quickly when traffic increases, ensuring responsiveness without manual intervention, while the maximum idle instances setting prevents over-provisioning and controls costs.

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Manual scaling with a fixed number of instances.

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Basic scaling with automatic instance creation.

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Resident instances with a minimum number of always-on instances.

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Custom scaling based on CPU utilization.

Question 12

A company uses Cloud Storage for backups of on-premises databases. They want to ensure that data is protected against accidental deletion or modification by users. Which combination of features should they enable?

Accepted Answer

Object versioning and bucket locking with retention policy.. Option D is correct because object versioning protects against accidental deletion or modification by preserving all versions of an object, while a bucket lock with a retention policy enforces a minimum retention period, preventing premature deletion or alteration. Together, they provide both recoverability and immutable compliance, which is essential for backup data integrity.

Answer

Object versioning and lifecycle management to delete old versions.

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Bucket locking with retention policy and bucket-level IAM restrictions.

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Bucket locking with retention policy and object holds.

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Object versioning and IAM conditions restricting access to specific IP ranges.

Question 13

A company uses Cloud Logging to monitor their application logs. They notice that some logs from their Compute Engine instances are missing. The instances have the required logging permission. What is the most likely cause?

Accepted Answer

The logging agent is not configured to send logs to Cloud Logging.. Compute Engine instances do not automatically send logs to Cloud Logging. They require the Cloud Logging agent (based on fluentd) to be installed and configured to forward logs. Even with correct IAM permissions, without the agent, logs will not be collected. Option B correctly identifies this missing agent as the most likely cause.

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The log sink is not configured correctly.

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The instances are using a custom image without the logging agent.

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The log bucket is in a different project.

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The log entries are being filtered by the exclusion filter.

Question 14

A company uses Cloud NAT to allow private instances to access the internet. They notice intermittent connectivity issues. What should they check first?

Accepted Answer

Cloud NAT gateway has at least one NAT IP address configured.. Intermittent connectivity issues when using Cloud NAT are most commonly caused by a lack of NAT IP addresses. Cloud NAT uses source network address translation (SNAT) to map private instance traffic to a public IP address; if the gateway has no NAT IP addresses configured, or if the number of concurrent connections exceeds the available port capacity of the assigned NAT IPs, packets are dropped, leading to intermittent failures. Checking that at least one NAT IP address is assigned is the first and most critical troubleshooting step.

Answer

Cloud NAT router has a configured IP address range.

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Cloud NAT gateway is in the same region as the instances.

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The VPC subnet has private Google access enabled.

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The instances have external IP addresses assigned.

Question 15

A company needs to deploy a stateless web application that can handle variable traffic. Which compute option is the most cost-effective and scales automatically?

Accepted Answer

App Engine standard environment with automatic scaling.. App Engine standard environment with automatic scaling is the most cost-effective and automatically scales to zero when there is no traffic, making it ideal for variable traffic stateless web applications. It abstracts infrastructure management, charges only for resources used, and handles scaling instantly without provisioning overhead.

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Google Kubernetes Engine (GKE) with cluster autoscaling.

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Compute Engine with managed instance groups and autoscaling.

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Compute Engine with preemptible VMs.

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Cloud Run with CPU always allocated.