PCDOE Applying site reliability engineering practices Practice Test 2 — 15 Questions

Question 1

Arrange the steps to migrate a monolithic application to microservices on Google Kubernetes Engine.

Accepted Answer

Identify contexts, then containerize, then deploy, then set up communication between microservices, then redirect traffic.. Identify contexts, containerize, deploy, set up communication, redirect traffic.

Answer

Containerize, then identify contexts, then deploy, then set up communication between microservices, then redirect traffic.

Answer

Identify contexts, then deploy, then containerize, then set up communication between microservices, then redirect traffic.

Answer

Identify contexts, then containerize, then set up communication between microservices, then deploy, then redirect traffic.

Question 2

Match each CI/CD concept to its definition.

Accepted Answer

Continuous Integration: The practice of frequently merging code changes into a shared repository, verified by automated builds and tests.. Continuous Integration focuses on frequent merging and automated testing; Continuous Delivery extends to staging deployment with manual production release; Continuous Deployment automates production releases. Common confusions arise from mixing these definitions.

Answer

Continuous Integration: The practice of automatically deploying code to production after each change.

Answer

Continuous Delivery: The practice of merging code changes frequently into a shared repository.

Question 3

Match each Google Cloud DevOps capability to its benefit.

Accepted Answer

Cloud Build: Automates build, test, and deployment. Cloud Build automates CI/CD pipelines, and Artifact Registry stores build artifacts. Common confusions involve mixing capabilities like monitoring (Cloud Monitoring) or source code management (Cloud Source Repositories) with other tools.

Answer

Cloud Build: Monitors application performance

Answer

Cloud Deploy: Manages source code repositories

Answer

Cloud Monitoring: Provides continuous delivery pipelines

Question 4

Your team receives an alert that the Error Reporting count for a critical service has increased tenfold in the last 10 minutes. You suspect a recent code deployment is the cause. What is the first action you should take?

Accepted Answer

Roll back the deployment to the previous version.. A tenfold increase in error reporting within 10 minutes strongly indicates a recent code deployment introduced a critical bug. The immediate priority is to restore service stability by rolling back the deployment to the previous known-good version, as this directly mitigates the root cause. Delaying the rollback risks further degradation of the service and potential data loss or corruption.

Answer

Disable the alert to reduce noise.

Answer

Increase the instance count to handle the load.

Answer

Open a post-mortem to document the incident.

Question 5

You are investigating a slow increase in latency for a service running on Compute Engine. You have Cloud Monitoring and Cloud Logging set up. Which tool would best help you identify the cause of the latency?

Accepted Answer

Cloud Trace. Cloud Trace is designed to capture latency data from distributed applications by tracing requests as they propagate through services. It provides detailed latency distributions and per-span breakdowns, allowing you to pinpoint which component or operation is causing the slowdown. For a Compute Engine service with Cloud Monitoring and Logging already in place, Cloud Trace is the most direct tool to analyze request-level latency.

Answer

Error Reporting

Answer

Cloud Profiler

Answer

Cloud Debugger

Question 6

Your team uses a canary deployment strategy on Google Kubernetes Engine (GKE). During a rollback, you notice that the rollback caused a brief period of downtime because the previous version's readiness probe was not properly configured. Which of the following best prevents this issue in the future?

Accepted Answer

Ensure that the readiness probe is tested as part of the pre-deployment validation.. The root cause of the downtime was a misconfigured readiness probe on the previous version. By testing the readiness probe as part of pre-deployment validation, you ensure that the probe correctly reflects the application's ability to serve traffic before it is used in a rollback. This prevents the scenario where a rollback deploys a version that fails its readiness check, causing the service to be removed from the load balancer and resulting in downtime.

Answer

Perform a gradual rollback with a managed instance group.

Answer

Use a blue/green deployment instead.

Answer

Use a Kubernetes Job to run a post-deployment validation.

Question 7

Your SLO for availability is 99.9% over a 30-day window. You want an alert that fires when the error budget burn rate is high, leaving less than 5% of the error budget remaining in the next 6 hours. What type of alerting policy should you configure?

Accepted Answer

A burn rate alert based on the forecasted consumption.. A burn rate alert based on forecasted consumption directly monitors the rate at which the error budget is being consumed and triggers when the projected remaining budget falls below 5% within the next 6 hours. This aligns with Google SRE best practices for proactive error budget management, using a multi-window, multi-burn-rate approach to detect rapid consumption before the budget is exhausted.

Answer

A custom log-based metric.

Answer

A static threshold alert based on the error rate.

Answer

An exponential decay alert.

Question 8

A GKE cluster node fails, causing pods to be rescheduled. However, some pods remain in 'CrashLoopBackOff' state. After examining logs, you find the application has a dependency on local SSD that was ephemeral. What is the best long-term solution?

Accepted Answer

Use PersistentVolumes with ReadWriteOnce access mode.. The application's dependency on local SSD (ephemeral storage) means that when the node fails, the data is lost, causing the pods to crash. PersistentVolumes (PVs) with ReadWriteOnce (RWO) access mode provide durable, node-independent storage that survives node failures, ensuring pods can be rescheduled on any node and access their data. This is the best long-term solution because it decouples storage from the node lifecycle, preventing CrashLoopBackOff due to missing local data.

Answer

Configure pod anti-affinity.

Answer

Increase the node pool size.

Answer

Use a DaemonSet to run the application.

Question 9

During a post-mortem, you identify that an incident was caused by a configuration change that was not reviewed. Which of the following is the most effective preventive action?

Accepted Answer

Implement a change management process with mandatory peer review.. A change management process with mandatory peer review directly addresses the root cause: a configuration change was made without oversight. By requiring at least one additional engineer to review and approve changes before implementation, the process catches misconfigurations, policy violations, or unintended side effects before they reach production. This is a preventive control, not a detective or corrective one, and aligns with ITIL best practices for change management.

Answer

Add more monitoring alerts.

Answer

Schedule weekly meetings to review changes.

Answer

Use a configuration management database (CMDB).

Question 10

Your incident response team uses a follow-the-sun model. An incident occurs during the Asia-Pacific shift, but the escalation path requires sign-off from the US-based team lead. This causes delays. What change should you recommend?

Accepted Answer

Implement a global incident commander role with delegated authority.. A global incident commander with delegated authority can make escalation decisions without waiting for a specific time-zone-based team lead. This role operates across shifts, ensuring that critical incident response actions are not delayed by geographic handoffs. In a follow-the-sun model, this role provides continuous, authoritative decision-making, aligning with ITIL incident management best practices for global teams.

Answer

Use a chatbot for automated responses.

Answer

Increase the number of US team members.

Answer

Schedule the US team lead to work overnight.

Question 11

You are debugging a production issue where a Cloud Function occasionally throws a 'memory limit exceeded' error. You want to inspect the memory usage at the time of the error. What should you do?

Accepted Answer

Enable Cloud Profiler and analyze the snapshot.. Cloud Profiler provides continuous, low-overhead profiling of CPU and memory usage, and its snapshot analysis can pinpoint memory allocation patterns at the time of a memory limit exceeded error. Unlike other tools, Profiler captures the call stack and memory consumption per function invocation, enabling you to identify the specific code path causing the spike.

Answer

Check Cloud Logging for memory metrics.

Answer

Use Cloud Trace to trace the invocations.

Answer

Use Cloud Debugger to set a breakpoint.

Question 12

Your application runs in two GCP regions. A regional outage occurs in the primary region. You have a Cloud Load Balancer with a failover backend. However, the failover did not trigger because the health check passed on a stale connection. What is the best solution?

Accepted Answer

Use a global load balancer with HTTP health checks based on application health.. A global load balancer with HTTP health checks can probe the actual application endpoint (e.g., /healthz) to verify end-to-end functionality, not just TCP connectivity. This prevents the stale connection issue where a TCP health check passes on an existing but broken session, ensuring failover triggers only when the application is genuinely unhealthy.

Answer

Use a passive health check.

Answer

Configure a custom health check that checks the database.

Answer

Use TCP health checks with a shorter interval.

Question 13

You are responding to an incident where a new release has caused increased error rates. Which TWO actions should you take immediately?

Accepted Answer

Notify stakeholders.. Immediately notifying stakeholders (such as product owners, support teams, and affected users) is a critical first step in incident management. It ensures transparency, sets expectations, and allows coordinated response efforts. In the PCDOE framework, stakeholder communication is prioritized to maintain trust and align business impact with technical remediation.

Answer

Disable the alert.

Answer

Push a hotfix without testing.

Answer

Create a post-mortem document.

Question 14

Which THREE of the following are recommended practices for writing effective post-mortem documents?

Accepted Answer

Focus on the root cause and contributing factors.. Effective post-mortem documents must focus on root cause analysis and contributing factors to identify systemic issues rather than individual errors. This aligns with the Site Reliability Engineering (SRE) principle of blameless post-mortems, which prioritize learning and process improvement over punishment. By analyzing the technical chain of events—such as a misconfigured load balancer or a cascading failure due to missing circuit breakers—teams can implement lasting fixes.

Answer

Assign blame to the responsible engineer.

Answer

Keep the document brief to save time.

Question 15

You are designing alerting policies for a microservice architecture. Which TWO metrics are most suitable for triggering a page to the on-call engineer?

Accepted Answer

Latency P99 exceeding the SLO target for 5 minutes.. Error budget burn rate and high latency (P99 breaching SLO) directly indicate customer-facing issues and require immediate attention. CPU and request count are less critical.

Answer

Number of requests per second.

Answer

CPU utilization at 50%.

Answer

Memory usage trend.