DevOps 1-40 Flashcards
1.
You support a Node js application running on Google Kubernetes Engine (GKE) in production. The application makes several HTTP requests to dependent applications. You
want to anticipate which dependent applications might cause performance issues. What should you do?
A. Instrument all applications with Stackdriver Profiler.
B. Instrument all applications with Stackdriver Trace and review inter-service HTTP requests.
C. Use Stackdriver Debugger to review the execution of logic within each application to instrument all applications
D. Modify the Node js application to log HTTP request and response times to dependent applications Use Stackdriver Logging to find dependent applications that are
performing poorly
B. Instrument all applications with Stackdriver Trace and review inter-service HTTP requests.
“The keyword is “make several requests to dependent app”. So you need trace for it.
Cloud Trace
Find performance bottlenecks in production.
Cloud Profiler
Continuous CPU and heap profiling to improve performance and reduce costs.”
2.
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
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
“I think it’s C, because dashboard viewer “Read-only access to dashboard configurations.”
SRE team wants to view data, not configurations.
correct there is no such role - “dashboard viewer” the correct name is monitoring dashboard configuration viewer (and the permission is - Read-only access to dashboard configurations).”
3.
Your organization wants to implement Site Reliability Engineering (SRE) culture and principles Recently, a service that you support had a limited outage. A manager on
another team asks you to provide a formal explanation of what happened so they can action remediations. What should you do?
A. Develop a postmortem that includes the root causes, resolution, lessons learned and a prioritized list of action items Share it with the manager only.
B. Develop a postmortem that includes the root causes, resolution, lessons learned, and a prioritized list of action items Share it on the engineering organization’s
document portal
C. Develop a postmortem that includes the root causes, resolution, lessons learned, the list of people responsible, and a list of action items for each person Share it with
the manager only.
D. Develop a postmortem that includes the root causes, resolution, lessons learned the list of people responsible and a list of action items for each person Share it on
the engineering organization’s document portal
B it could be based on this In order to maintain a healthy postmortem culture within an organization, it’s important to share postmortems as widely as possible.
4.
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 entnes 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
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
- 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 cloudplatform 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
D. SSH to the VM and execute the following commands on your VM: ps ax | grep fluentd.
I think D
Reason : When an instance is created, we can specify which service account the instance uses when calling Google Cloud APIs. The instance is automatically configured with access scope and one such access scope is monitoring.write (Link : https://cloud.google.com/compute/docs/access/service- read is to publish metric data and logging.write is to write compute engine logs.
Considering above, I believe D as the answer (check whether the agent is running)
6.
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 momtonng
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.
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.
“A: No becauseThere is not Structure attribute to create a http request in the steps and remember you want minimize the development effort.
B: The same A
C: minimize the development effort
D: Its OK
To receive messages from push subscriptions, use a webhook and process the POST requests that Pub/Sub sends to the push endpoint. For more information about processing these POST requests in App Engine, see Writing and responding to Pub/Sub messages.”
https: //cloud.google.com/pubsub/docs/push
https: //cloud.google.com/build/docs/subscribe-build-notifications
7.
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.
A. Compare the canary with a new deployment of the current production version.
“Ans A
https://spinnaker.io/guides/user/canary/best-practices/#compare-canary-against-baseline-not-against-production
You might be tempted to compare the canary deployment against your current production deployment. Instead always compare the canary against an equivalent baseline, deployed at the same time.
The baseline uses the same version and configuration that is currently running in production, but is otherwise identical to the canary:
Same time of deployment
Same size of deployment
Same type and amount of traffic
In this way, you control for version and configuration only, and you reduce factors that could affect the analysis, like the cache warmup time, the heap size, and so on.”
8.
You support a high-traffic web application and want to ensure that the home page loads in a timely manner.As a first step, you decide to implement a Service Level Indicator (SLI) to represent home page request latency with an acceptable page load time set to 100 ms. What is the Google-recommended way of calculating this SLI?
A. Bucketize the request latencies into ranges, and then compute the percentile at 100 ms
B. Bucketize the request latencies into ranges, and then compute the median and 90th percentiles
C. Count the number of home page requests that load in under 100 ms, and then divide by the total number of home page requests.
D, Count the number of home page request that load in under 100 ms, and then divide by the total number of all web application requests
C. Count the number of home page requests that load in under 100 ms, and then divide by the total number of home page requests.
“Ans C
https://sre.google/workbook/implementing-slos/
In the SRE principles book, it’s recommended treating the SLI as the ratio of two numbers: the number of good events divided by the total number of events. For example:
Number of successful HTTP requests / total HTTP requests (success rate)”
9.
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, i ]
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 Cl server Add a suite of unit tests to your code and have your Cl server run them on commit and verify any changes
Ans: B & E
A: No, More peers to review dont automate anything
B: Ok CD
C: No, Linting is for code format
D: No, Integration test are needed but its better automatically
E: Ok CI
10.
You have a pool of application servers running on Compute Engine. You need to provide a secure solution that requires the least amount of configuration and allows developers
to easily access application logs for troubleshooting How would you implement the solution on GCP?
A.
•Deploy the Stackdriver logging agent to the application servers.
•Give the developers the IAM Logs Viewer role to access Stackdriver and view logs
B.
•Deploy the Stackdriver logging agent to the application servers
•Give the developers the IAM Logs Private Logs Viewer role to access Stackdriver and view logs
C.
•Deploy the Stackdriver monitoring agent to the application servers
•Give the developers the IAM Monitoring Viewer role to access Stackdriver and view metrics
D.
•Install the gsutil command line tool on your application servers
•Write a script using gsutil to upload your application log to a Cloud Storage bucket, and then schedule it to run via cron every 5 minutes.
•Give the developers the IAM Object Viewer access to view the logs in the specified bucket.
tvt_vn/ebay
A.
•Deploy the Stackdriver logging agent to the application servers.
•Give the developers the IAM Logs Viewer role to access Stackdriver and view logs
“Answer A
roles/logging.viewer (Logs Viewer) gives you read-only access to all features of Logging, except Access Transparency logs and Data Access audit logs.
https://cloud.google.com/logging/docs/access-control”
11.
You support the backend of a mobile phone game that runs on a Google Kubernetes Engine (GKE) cluster.The application is serving HTTP requests from users. You need to implement a solution that will reduce the network cost. What should you do?
A. Configure the VPC as a Shared VPC Host project
B. Configure your network services on the Standard Tier
C. Configure your Kubernetes cluster as a Private Cluster
D. Configure a Google Cloud HTTP Load Balancer as Ingress
D. Configure a Google Cloud HTTP Load Balancer as
“A: No, Doest make sense
B: Who says that we are using a premium tier?
C: This does not help with the network cost?
D: Ok :)
Costs associated with a load balancer are charged to the project containing the load balancer components.
Because of these benefits, container-native load balancing is the recommended solution for load balancing through Ingress. When NEGs are used with GKE Ingress, the Ingress controller facilitates the creation of all aspects of the L7 load balancer. This includes creating the virtual IP address, forwarding rules, health checks, firewall rules, and more.”
https://cloud.google.com/architecture/best-practices-for-running-cost-effective-kubernetes-applications-on-gke
12.
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
B. Develop a post-mortem to be distributed to stakeholders
“B, blameless postmortem
https://sre.google/sre-book/postmortem-culture/”
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 capacity
A.
Verify the maximum node pool size, enable a horizontal pod autoscaler, and then perform a load test to verify your expected resource needs.
“A: Correct. The Horizontal Pod Autoscaler changes the shape of your Kubernetes workload by automatically increasing or decreasing the number of Pods in response to the workload’s CPU or memory consumption
B: Incorrect. It is not based on the CPU its based on the workload
C: No, Hope is not an strategy
D: No, have more resource than needed”
14.
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 trigger 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).
B.
Use Cloud Pub/Sub to trigger a Spinnaker pipeline
B is correct : https://cloud.google.com/architecture/continuous-delivery-toolchain-spinnaker-cloud#triggering_a_spinnaker_pipeline_when_a_docker_image_is_pushed_to_container_registry
15.
Your product is currently deployed in three Google Cloud Platform (GCP) zones with your users divided between the zones. You can fail over from one zone to another, but it
causes a 10-minute service disruption for the affected users. You typically experience a database failure once per quarter and can detect it within five minutes. You are cataloging the reliability risks of a new real-time chat feature for your product. You catalog the following information for each risk:
•Mean Time to Detect (MTTD) in minutes
•Mean Time to Repair (MTTR) in minutes
•Mean Time Between Failure (MTBF) in days
•User Impact Percentage
The chat feature requires a new database system that takes twice as long to successfully fail over between zones. You want to account for the risk of the new database failing in one zone. What would be the values for the risk of database failover with the new system?
A. MTTD: 5 MTTR: 10 MTBF 90 Impact 33%
B. MTTD 5 MTTR 20 MTBF: 90 Impact: 33%
C. MTTD: 5 MTTR 10 MTBF 90 Impact: 50%
D. MTTD: 5 MTTR: 20 MTBF: 90 Impact 50%
B. MTTD 5 MTTR 20 MTBF: 90 Impact: 33%
16.
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 Cl/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
D. Set up the Kubernetes Engine clusters with Binary Authorization
“D because binary authorization is deploy time security tool and it will allow only trusted and attested containers into GKE”
