Deck 14: Professional Cloud DevOps Engineer

Question 1

You are running an experiment to see whether your users like a new feature of a web application. Shortly after deploying the feature as a canary release, you receive a spike in the number of 500 errors sent to users, and your monitoring reports show increased latency. You want to quickly minimize the negative impact on users. What should you do first?

A) Roll back the experimental canary release.
B) Start monitoring latency, traffic, errors, and saturation.
C) Record data for the postmortem document of the incident.
D) Trace the origin of 500 errors and the root cause of increased latency.

Answer 1

Trace the origin of 500 errors and the root cause of increased latency.

Question 2

You encountered a major service outage that affected all users of the service for multiple hours. After several hours of incident management, the service returned to normal, and user access was restored. You need to provide an incident summary to relevant stakeholders following the Site Reliability Engineering recommended practices. What should you do first?

A) Call individual stakeholders to explain what happened.
B) Develop a post-mortem to be distributed to stakeholders.
C) Send the Incident State Document to all the stakeholders.
D) Require the engineer responsible to write an apology email to all stakeholders.

Answer 2

Call individual stakeholders to explain what happened.

Question 3

Your company experiences bugs, outages, and slowness in its production systems. Developers use the production environment for new feature development and bug fixes. Configuration and experiments are done in the production environment, causing outages for users. Testers use the production environment for load testing, which often slows the production systems. You need to redesign the environment to reduce the number of bugs and outages in production and to enable testers to toad test new features. What should you do?

A) Create an automated testing script in production to detect failures as soon as they occur.
B) Create a development environment with smaller server capacity and give access only to developers and testers.
C) Secure the production environment to ensure that developers can't change it and set up one controlled update per year.
D) Create a development environment for writing code and a test environment for configurations, experiments, and load testing.

Answer 3

Create an automated testing script in production to detect failures as soon as they occur.

Question 4

Your application images are built wing Cloud Build and pushed to Google Container Registry (GCR). You want to be able to specify a particular version of your application for deployment based on the release version tagged in source control. What would you do when you push the image?

A) Reference the image digest in the source control tag.
B) Supply the source control tag as a parameter within the image name.
C) Use Cloud Build to include the release version tag in the application image.
D) Use GCR digest versioning to match the image to the tag in source control.

Question 5

Your application images are built and pushed to Google Container Registry (GCR). You want to build an automated pipeline that deploys the application when the image is updated while minimizing the development effort. What should you do?

A) Use Cloud Build to trigger a Spinnaker pipeline.
B) Use Cloud Pub/Sub to bigger a Spinnaker pipeline.
C) Use a custom builder in Cloud Build to trigger Jenkins pipeline.
D) Use Cloud Pub/Sub to trigger a custom deployment service running in Google Kubernetes Engine (GKE).

Question 6

You support an application deployed on Compute Engine. The application connects to a Cloud SQL instance to store and retrieve data. After an update to the application, users report errors showing database timeout messages. The number of concurrent active users remained stable. You need to find the most probable cause of the database timeout. What should you do?

A) Check the serial port logs of the Compute Engine instance.
B) Use Stackdriver Profiler to visualize the resources utilization throughout the application.
C) Determine whether there is an increased number of connections to the Cloud SQL instance.
D) Use Cloud Security Scanner to see whether your Cloud SQL is under a Distributed Denial of Service (DDoS) attack.

Question 7

You deploy a new release of an internal application during a weekend maintenance window when there is minimal user tragic. After the window ends, you learn that one of the new features isn't working as expected in the production environment. After an extended outage, you roll back the new release and deploy a fix. You want to modify your release process to reduce the mean time to recovery so you can avoid extended outages in the future. What should you do? (Choose two.)

A) Before merging new code, require 2 different peers to review the code changes.
B) Adopt the blue/green deployment strategy when releasing new code via a CD server.
C) Integrate a code linting tool to validate coding standards before any code is accepted into the repository.
D) Require developers to run automated integration tests on their local development environments before release.
E) Configure a CI server. Add a suite of unit tests to your code and have your CI server run them on commit and verify any changes.

Question 8

You are part of an organization that follows SRE practices and principles. You are taking over the management of a new service from the Development Team, and you conduct a Production Readiness Review (PRR). After the PRR analysis phase, you determine that the service cannot currently meet its Service Level Objectives (SLOs). You want to ensure that the service can meet its SLOs in production. What should you do next?

A) Adjust the SLO targets to be achievable by the service so you can bring it into production.
B) Notify the development team that they will have to provide production support for the service.
C) Identify recommended reliability improvements to the service to be completed before handover.
D) Bring the service into production with no SLOs and build them when you have collected operational data.

Question 9

You support an application running on App Engine. The application is used globally and accessed from various device types. You want to know the number of connections. You are using Stackdriver Monitoring for App Engine. What metric should you use?

A) flex/connections/current
B) tcp_ssl_proxy/new_connections
C) tcp_ssl_proxy/open_connections
D) flex/instance/connections/current

Question 10

You support an e-commerce application that runs on a large Google Kubernetes Engine (GKE) cluster deployed on-premises and on Google Cloud Platform. The application consists of microservices that run in containers. You want to identify containers that are using the most CPU and memory. What should you do?

A) Use Stackdriver Kubernetes Engine Monitoring.
B) Use Prometheus to collect and aggregate logs per container, and then analyze the results in Grafana.
C) Use the Stackdriver Monitoring API to create custom metrics, and then organize your containers using groups.
D) Use Stackdriver Logging to export application logs to BigQuery, aggregate logs per container, and then analyze CPU and memory consumption.

Question 11

Your application artifacts are being built and deployed via a CI/CD pipeline. You want the CI/CD pipeline to securely access application secrets. You also want to more easily rotate secrets in case of a security breach. What should you do?

A) Prompt developers for secrets at build time. Instruct developers to not store secrets at rest.
B) Store secrets in a separate configuration file on Git. Provide select developers with access to the configuration file.
C) Store secrets in Cloud Storage encrypted with a key from Cloud KMS. Provide the CI/CD pipeline with access to Cloud KMS via IAM.
D) Encrypt the secrets and store them in the source code repository. Store a decryption key in a separate repository and grant your pipeline access to it.

Question 12

You need to run a business-critical workload on a fixed set of Compute Engine instances for several months. The workload is stable with the exact amount of resources allocated to it. You want to lower the costs for this workload without any performance implications. What should you do?

A) Purchase Committed Use Discounts.
B) Migrate the instances to a Managed Instance Group.
C) Convert the instances to preemptible virtual machines.
D) Create an Unmanaged Instance Group for the instances used to run the workload.

Question 13

You are performing a semi-annual capacity planning exercise for your flagship service. You expect a service user growth rate of 10% month-over-month over the next six months. Your service is fully containerized and runs on Google Cloud Platform (GCP), using a Google Kubernetes Engine (GKE) Standard regional cluster on three zones with cluster autoscaler enabled. You currently consume about 30% of your total deployed CPU capacity, and you require resilience against the failure of a zone. You want to ensure that your users experience minimal negative impact as a result of this growth or as a result of zone failure, while avoiding unnecessary costs. How should you prepare to handle the predicted growth?

A) Verify the maximum node pool size, enable a horizontal pod autoscaler, and then perform a load test to verify your expected resource needs.
B) Because you are deployed on GKE and are using a cluster autoscaler, your GKE cluster will scale automatically regardless of growth rate.
C) Because you are at only 30% utilization, you have significant headroom and you won't need to add any additional capacity for this rate of growth.
D) Proactively add 60% more node capacity to account for six months of 10% growth rate, and then perform a load test to make sure you have enough.

Question 14

You use Spinnaker to deploy your application and have created a canary deployment stage in the pipeline. Your application has an in-memory cache that loads objects at start time. You want to automate the comparison of the canary version against the production version. How should you configure the canary analysis?

A) Compare the canary with a new deployment of the current production version.
B) Compare the canary with a new deployment of the previous production version.
C) Compare the canary with the existing deployment of the current production version.
D) Compare the canary with the average performance of a sliding window of previous production versions.

Question 15

Your company follows Site Reliability Engineering practices. You are the person in charge of Communications for a large, ongoing incident affecting your customer-facing applications. There is still no estimated time for a resolution of the outage. You are receiving emails from internal stakeholders who want updates on the outage, as well as emails from customers who want to know what is happening. You want to efficiently provide updates to everyone affected by the outage. What should you do?

A) Focus on responding to internal stakeholders at least every 30 minutes. Commit to "next update" times.
B) Provide periodic updates to all stakeholders in a timely manner. Commit to a "next update" time in all communications.
C) Delegate the responding to internal stakeholder emails to another member of the Incident Response Team. Focus on providing responses directly to customers.
D) Provide all internal stakeholder emails to the Incident Commander, and allow them to manage internal communications. Focus on providing responses directly to customers.

Question 16

You have a set of applications running on a Google Kubernetes Engine (GKE) cluster, and you are using Stackdriver Kubernetes Engine Monitoring. You are bringing a new containerized application required by your company into production. This application is written by a third party and cannot be modified or reconfigured. The application writes its log information to /var/log/app_messages.log, and you want to send these log entries to Stackdriver Logging. What should you do?

A) Use the default Stackdriver Kubernetes Engine Monitoring agent configuration.
B) Deploy a Fluentd daemonset to GKE. Then create a customized input and output configuration to tail the log file in the application's pods and write to Stackdriver Logging.
C) Install Kubernetes on Google Compute Engine (GCE) and redeploy your applications. Then customize the built-in Stackdriver Logging configuration to tail the log file in the application's pods and write to Stackdriver Logging.
D) Write a script to tail the log file within the pod and write entries to standard output. Run the script as a sidecar container with the application's pod. Configure a shared volume between the containers to allow the script to have read access to /var/log in the application container.

Question 17

You created a Stackdriver chart for CPU utilization in a dashboard within your workspace project. You want to share the chart with your Site Reliability Engineering (SRE) team only. You want to ensure you follow the principle of least privilege. What should you do?

A) Share the workspace Project ID with the SRE team. Assign the SRE team the Monitoring Viewer IAM role in the workspace project.
B) Share the workspace Project ID with the SRE team. Assign the SRE team the Dashboard Viewer IAM role in the workspace project.
C) Click "Share chart by URL" and provide the URL to the SRE team. Assign the SRE team the Monitoring Viewer IAM role in the workspace project.
D) Click "Share chart by URL" and provide the URL to the SRE team. Assign the SRE team the Dashboard Viewer IAM role in the workspace project.

Question 18

You are managing the production deployment to a set of Google Kubernetes Engine (GKE) clusters. You want to make sure only images which are successfully built by your trusted CI/CD pipeline are deployed to production. What should you do?

A) Enable Cloud Security Scanner on the clusters.
B) Enable Vulnerability Analysis on the Container Registry.
C) Set up the Kubernetes Engine clusters as private clusters.
D) Set up the Kubernetes Engine clusters with Binary Authorization.

Question 19

You use a multiple step Cloud Build pipeline to build and deploy your application to Google Kubernetes Engine (GKE). You want to integrate with a third-party monitoring platform by performing a HTTP POST of the build information to a webhook. You want to minimize the development effort. What should you do?

A) Add logic to each Cloud Build step to HTTP POST the build information to a webhook.
B) Add a new step at the end of the pipeline in Cloud Build to HTTP POST the build information to a webhook.
C) Use Stackdriver Logging to create a logs-based metric from the Cloud Build logs. Create an Alert with a Webhook notification type.
D) Create a Cloud Pub/Sub push subscription to the Cloud Build cloud-builds PubSub topic to HTTP POST the build information to a webhook. Create a Cloud Pub/Sub push subscription to the Cloud Build cloud-builds PubSub topic to HTTP POST the build information to a webhook.

Question 20

You are running an application in a virtual machine (VM) using a custom Debian image. The image has the Stackdriver Logging agent installed. The VM has the cloud-platform scope. The application is logging information via syslog. You want to use Stackdriver Logging in the Google Cloud Platform Console to visualize the logs. You notice that syslog is not showing up in the "All logs" dropdown list of the Logs Viewer. What is the first thing you should do?

A) Look for the agent's test log entry in the Logs Viewer.
B) Install the most recent version of the Stackdriver agent.
C) Verify the VM service account access scope includes the monitoring.write scope. Verify the VM service account access scope includes the monitoring.write scope.
D) SSH to the VM and execute the following commands on your VM: ps ax | grep fluentd . SSH to the VM and execute the following commands on your VM: ps ax | grep fluentd .

Question 21

Your team has recently deployed an NGINX-based application into Google Kubernetes Engine (GKE) and has exposed it to the public via an HTTP Google Cloud Load Balancer (GCLB) ingress. You want to scale the deployment of the application's frontend using an appropriate Service Level Indicator (SLI). What should you do?

A) Configure the horizontal pod autoscaler to use the average response time from the Liveness and Readiness probes.
B) Configure the vertical pod autoscaler in GKE and enable the cluster autoscaler to scale the cluster as pods expand.
C) Install the Stackdriver custom metrics adapter and configure a horizontal pod autoscaler to use the number of requests provided by the GCLB.
D) Expose the NGINX stats endpoint and configure the horizontal pod autoscaler to use the request metrics exposed by the NGINX deployment.

Question 22

You need to deploy a new service to production. The service needs to automatically scale using a Managed Instance Group (MIG) and should be deployed over multiple regions. The service needs a large number of resources for each instance and you need to plan for capacity. What should you do?

A) Use the n1-highcpu-96 machine type in the configuration of the MIG.
B) Monitor results of Stackdriver Trace to determine the required amount of resources.
C) Validate that the resource requirements are within the available quota limits of each region.
D) Deploy the service in one region and use a global load balancer to route traffic to this region.

Question 23

You need to reduce the cost of virtual machines (VM) for your organization. After reviewing different options, you decide to leverage preemptible VM instances. Which application is suitable for preemptible VMs?

A) A scalable in-memory caching system.
B) The organization's public-facing website.
C) A distributed, eventually consistent NoSQL database cluster with sufficient quorum.
D) A GPU-accelerated video rendering platform that retrieves and stores videos in a storage bucket.

Question 24

You support an application running on GCP and want to configure SMS notifications to your team for the most critical alerts in Stackdriver Monitoring. You have already identified the alerting policies you want to configure this for. What should you do?

A) Download and configure a third-party integration between Stackdriver Monitoring and an SMS gateway. Ensure that your team members add their SMS/phone numbers to the external tool.
B) Select the Webhook notifications option for each alerting policy, and configure it to use a third-party integration tool. Ensure that your team members add their SMS/phone numbers to the external tool.
C) Ensure that your team members set their SMS/phone numbers in their Stackdriver Profile. Select the SMS notification option for each alerting policy and then select the appropriate SMS/phone numbers from the list.
D) Configure a Slack notification for each alerting policy. Set up a Slack-to-SMS integration to send SMS messages when Slack messages are received. Ensure that your team members add their SMS/phone numbers to the external integration.

Question 25

You support an application that stores product information in cached memory. For every cache miss, an entry is logged in Stackdriver Logging. You want to visualize how often a cache miss happens over time. What should you do?

A) Link Stackdriver Logging as a source in Google Data Studio. Filter the logs on the cache misses.
B) Configure Stackdriver Profiler to identify and visualize when the cache misses occur based on the logs.
C) Create a logs-based metric in Stackdriver Logging and a dashboard for that metric in Stackdriver Monitoring.
D) Configure BigQuery as a sink for Stackdriver Logging. Create a scheduled query to filter the cache miss logs and write them to a separate table.

Question 26

Your organization recently adopted a container-based workflow for application development. Your team develops numerous applications that are deployed continuously through an automated build pipeline to a Kubernetes cluster in the production environment. The security auditor is concerned that developers or operators could circumvent automated testing and push code changes to production without approval. What should you do to enforce approvals?

A) Configure the build system with protected branches that require pull request approval.
B) Use an Admission Controller to verify that incoming requests originate from approved sources.
C) Leverage Kubernetes Role-Based Access Control (RBAC) to restrict access to only approved users.
D) Enable binary authorization inside the Kubernetes cluster and configure the build pipeline as an attestor.

Question 27

Your application services run in Google Kubernetes Engine (GKE). You want to make sure that only images from your centrally-managed Google Container Registry (GCR) image registry in the altostrat-images project can be deployed to the cluster while minimizing development time. What should you do?

A) Create a custom builder for Cloud Build that will only push images to gcr.io/altostrat-images.
B) Use a Binary Authorization policy that includes the whitelist name pattern gcr.io/altostrat-images/.
C) Add logic to the deployment pipeline to check that all manifests contain only images from gcr.io/altostrat-images.
D) Add a tag to each image in gcr.io/altostrat-images and check that this tag is present when the image is deployed.

Question 28

Your team uses Cloud Build for all CI/CD pipelines. You want to use the kubectl builder for Cloud Build to deploy new images to Google Kubernetes Engine (GKE). You need to authenticate to GKE while minimizing development effort. What should you do?

A) Assign the Container Developer role to the Cloud Build service account.
B) Specify the Container Developer role for Cloud Build in the cloudbuild.yaml file.
C) Create a new service account with the Container Developer role and use it to run Cloud Build.
D) Create a separate step in Cloud Build to retrieve service account credentials and pass these to kubectl.