PCDE Applying Site Reliability Engineering Practices to a Service Practice Test 8 — 15 Questions

Question 1

A site reliability team wants to define an SLO for a service with a target availability of 99.9% over a 30-day window. The error budget is exhausted. Which action MUST the team take?

Accepted Answer

Freeze all non-critical releases until the budget recovers.. When the error budget is exhausted, the SRE practice is to stop all non-critical releases and focus on improving reliability, as defined by the error budget policy. This aligns with SRE principles of using the budget to balance velocity and stability.

Answer

Ignore the budget and continue normal development.

Answer

Deploy a new feature to attract more users.

Answer

Increase the SLO to 99.95% to make up for lost budget.

Question 2

An SRE wants to measure latency SLI for a web service. Which metric is the BEST indicator of user-perceived performance?

Accepted Answer

Proportion of requests served in under 200ms.. The proportion of requests that complete within a defined threshold (e.g., 200ms) directly measures user-perceived performance. Other options are less representative.

Answer

Maximum latency observed in the last 5 minutes.

Answer

Average latency over the last hour.

Answer

99th percentile latency.

Question 3

A team uses Cloud Monitoring to create an SLO for a request-based service. They want to alert when the error budget burn rate exceeds 14x the budget for a short window. Which alert type and window should they configure?

Accepted Answer

Fast burn alert with a 1-hour window.. A fast burn alert fires when the burn rate is very high over a short window (1 hour). 14x burn rate means the entire budget would be consumed in ~1/14 of the SLO window. The correct configuration is a fast burn alert with a 1-hour window.

Answer

Slow burn alert with a 6-hour window.

Answer

Fast burn alert with a 6-hour window.

Answer

Slow burn alert with a 1-hour window.

Question 4

An SRE team notices that a routine database cleanup task takes 30 minutes of manual effort each week. The task does not add enduring value and scales linearly with the number of databases. How should the team classify this work?

Accepted Answer

Toil.. This work is manual, repetitive, does not add enduring value, and scales with service growth — the classic definition of toil. SREs should automate it and track it against the toil budget.

Answer

Technical debt.

Answer

Operational overhead.

Answer

Engineering project.

Question 5

After a major incident, the SRE team conducts a postmortem. Which practice is ESSENTIAL for a blameless culture?

Accepted Answer

Focus on systemic failures and contributing factors.. Blameless postmortems focus on systemic causes and contributing factors, not individual mistakes. This encourages honest reporting and learning.

Answer

Assign action items with owners and due dates.

Answer

Skip the postmortem if the incident was minor.

Answer

Identify the person who caused the incident.

Question 6

An SRE team wants to perform fault injection testing on a GKE cluster by injecting network latency into a specific set of pods. Which tool should they use?

Accepted Answer

Chaos Mesh on GKE.. Chaos Mesh is an open-source chaos engineering platform specifically designed for Kubernetes. It can inject faults like network latency into targeted pods.

Answer

Cloud Functions with network disruption script.

Answer

Traffic Director fault injection.

Answer

Google Cloud Armor.

Question 7

A team uses Cloud Monitoring to track availability SLI as good-request-count / valid-request-count. They want to create a window-based SLO. Which metric filter should they use for the numerator?

Accepted Answer

count of minutes where availability >= 99.9%.. Window-based SLOs use 'good minutes' where the availability is above a threshold (e.g., 99.9% of requests succeeded). The numerator is the count of minutes where the SLI was good.

Answer

total number of minutes in a month.

Answer

count of requests with status 200.

Answer

count of errors.

Question 8

An SLA guarantees 99.9% monthly uptime. The team's SLO is 99.95% and error budget is 0.05%. What is the maximum allowed downtime per month according to the SLA?

Accepted Answer

43.8 minutes.. 99.9% uptime allows 0.1% downtime. Per month (30 days = 43,800 minutes), 0.1% is 43.8 minutes. The SLO is stricter but the question asks for SLA allowance.

Answer

7.2 hours.

Answer

21.9 minutes.

Answer

4.38 hours.

Question 9

During an incident, the incident commander delegates tasks to multiple teams. Which communication model is MOST effective to reduce noise?

Accepted Answer

Use a single incident channel where all teams post updates.. The recommended approach is to use a single communication channel (e.g., a dedicated chat room) for all incident-related updates, and the incident commander coordinates via that channel.

Answer

Use email for updates to avoid real-time noise.

Answer

Each team communicates in separate channels.

Answer

All updates go through the incident commander only.

Question 10

An SRE team wants to automate a manual process that involves multiple steps and conditional logic (e.g., if a backup fails, retry with a different method). Which TWO Google Cloud services can they use to orchestrate this workflow? (Choose 2 answers)

Accepted Answer

Cloud Composer. Cloud Workflows and Cloud Composer (based on Apache Airflow) are both orchestration services that can handle complex workflows with branching, retries, and conditionals. Cloud Functions is for individual functions, Cloud Build is for CI/CD, and Pub/Sub is for messaging.

Answer

Pub/Sub

Answer

Cloud Functions

Answer

Cloud Build

Question 11

A team wants to implement error budget alerts in Cloud Monitoring. They need TWO policies to detect both rapid and gradual budget consumption. Which TWO alert policies should they configure? (Choose 2 answers)

Accepted Answer

Fast burn alert with 14x burn rate over 1 hour.. The standard practice is to create a fast burn alert (e.g., 14x burn rate over 1 hour) for rapid consumption, and a slow burn alert (e.g., 5x burn rate over 6 hours) for gradual consumption. The other options are not standard.

Answer

Single alert with a burn rate of 10x over 1 hour.

Answer

Alert on error budget remaining < 10%.

Answer

Fast burn alert with 5x burn rate over 6 hours.

Question 12

Which TWO statements correctly describe characteristics of toil in SRE? (Choose 2 answers)

Accepted Answer

Toil is repetitive and manually performed.. Toil in SRE is defined as manual, repetitive work that does not produce enduring value. As a service scales, toil typically increases rather than decreases. Option B correctly identifies toil as repetitive and manually performed. Option E correctly states that toil provides no enduring value. Option A is incorrect because toil is not always automatable; some toil may be difficult or impractical to automate. Option C is incorrect because toil scales with service growth, not decreases. Option D is incorrect because toil does not add enduring value; that is a characteristic of engineering work.

Answer

Toil is always automatable.

Answer

Toil decreases as the service scales.

Answer

Toil adds enduring value to the service.

Question 13

A team wants to reduce toil by automating a recurring cloud resource update. Which THREE Google Cloud services can be used together to build an automated pipeline? (Choose 3 answers)

Accepted Answer

Cloud Scheduler. Cloud Build can run automation scripts, Cloud Functions can be triggered by events, and Cloud Scheduler can trigger periodic jobs. Together they can form a pipeline. Pub/Sub and Deployment Manager are also possible but the question asks for THREE from the given set that are commonly used together.

Answer

Cloud Pub/Sub

Answer

Cloud Deployment Manager

Question 14

An SRE team is conducting a blameless postmortem after an outage. Which THREE elements should be included in the postmortem document? (Choose 3 answers)

Accepted Answer

Contributing factors (e.g., why the failure happened).. A good postmortem includes a timeline, contributing factors, and action items with owners. Blaming individuals is counterproductive, and root cause is often too simplistic; the focus should be on contributing factors.

Answer

Identification of the person responsible.

Answer

Single root cause.

Question 15

A team wants to implement chaos engineering on GKE to test resilience. Which THREE fault types can be injected using Chaos Mesh? (Choose 3 answers)

Accepted Answer

Pod failure (kill pods).. Chaos Mesh supports many fault types including pod failure (kill), network latency, and CPU stress. A whole cluster deletion is not a typical Chaos Mesh experiment (too destructive), and code injection is not a built-in fault type.

Answer

Code injection into running containers.

Answer

Whole cluster deletion.