PCD Deploying applications Practice Test 3 — 15 Questions

Question 1

A developer is troubleshooting a deployment on Cloud Run. The service fails with 'Container failed to start' error. The container image is built from a Dockerfile that uses CMD ['npm', 'start']. What is the most likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The application does not listen on the port specified by the PORT environment variable.. Cloud Run requires the containerized application to listen on the port specified by the PORT environment variable (default 8080). If the application is hardcoded to listen on a different port (e.g., 3000) or does not read the PORT variable, Cloud Run's health checks and routing will fail, resulting in a 'Container failed to start' error. The CMD instruction is correct for starting npm, but the application must bind to the correct port.

Answer

The Dockerfile uses CMD instead of ENTRYPOINT.

Answer

The container image is too large and exceeds the memory limit.

Answer

The Cloud Run service does not have permission to pull the image from Container Registry.

Question 2

An organization runs a stateful application on GKE that uses PersistentVolumes. They want to perform a rolling update of the application without disrupting the underlying persistent data. What should they use?

Accepted Answer

A StatefulSet with a PersistentVolumeClaim template.. A StatefulSet is the correct choice because it is designed for stateful applications that require stable, unique network identifiers and persistent storage. By including a PersistentVolumeClaim template in the StatefulSet spec, each Pod gets its own dedicated PersistentVolume that persists across rescheduling and rolling updates, ensuring data is not disrupted.

Answer

A ReplicaSet with a headless service.

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A DaemonSet with a PodDisruptionBudget.

Answer

A Deployment with a PersistentVolumeClaim template.

Question 3

A developer wants to automatically deploy a new version of an application to App Engine Standard every time code is pushed to the main branch of a Cloud Source Repositories repository. Which service should be used?

Accepted Answer

Cloud Build. Cloud Build is the correct service because it is a fully managed CI/CD platform that integrates natively with Cloud Source Repositories and App Engine Standard. You can configure a Cloud Build trigger to automatically build and deploy your application whenever code is pushed to the main branch, using a cloudbuild.yaml file that specifies the build steps and the `gcloud app deploy` command.

Answer

Cloud Run

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Cloud Scheduler

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Cloud Deploy

Question 4

A company has a multi-region deployment on GKE and needs to route traffic to the closest regional cluster based on user location. They want to minimize latency. Which approach should they use?

Accepted Answer

Use a global external HTTP(S) Load Balancer with backend services pointing to NEGs in each region.. A global external HTTP(S) Load Balancer uses Anycast IP addresses and is backed by backend services that reference Network Endpoint Groups (NEGs) in each regional GKE cluster. This allows the load balancer to direct traffic to the closest healthy backend based on the user's geographic location and the load balancer's proximity algorithm, minimizing latency without requiring DNS-based routing.

Answer

Create separate internal load balancers in each region and use Cloud DNS geo-routing.

Answer

Configure an external TCP/UDP Network Load Balancer in each region and use Cloud DNS geo-routing.

Answer

Deploy a single regional cluster and use Cloud CDN to cache content globally.

Question 5

A developer is deploying a microservice on GKE that needs to be accessible only from within the same VPC network. The microservice must have a stable, internal IP address that does not change when pods are updated. Which options should be used?

Accepted Answer

Use a Service of type LoadBalancer with the annotation 'cloud.google.com/load-balancer-type: Internal'.. Deploying a Service of type LoadBalancer with the annotation 'cloud.google.com/load-balancer-type: Internal' creates an internal TCP/UDP load balancer within the VPC network. This provides a stable, internal IP address that persists across pod updates, as the load balancer's IP is independent of the underlying pods and is managed by Google Cloud's networking layer.

Answer

Use a Service of type NodePort with a static reservation.

Answer

Use a Service of type ClusterIP with a static IP.

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Use a Service of type ExternalName pointing to the pods' internal IPs.

Question 6

Which TWO strategies can be used to reduce cold start latency in Cloud Run? (Choose 2)

Accepted Answer

Set a minimum number of instances (min-instances) to keep instances warm.. Setting a minimum number of instances (min-instances) ensures that a specified number of container instances are always running and ready to serve requests, eliminating the cold start latency that occurs when an instance must be started from scratch. This pre-warming strategy directly reduces the time users wait for the first request to be processed.

Answer

Increase the maximum number of concurrent requests per instance.

Answer

Deploy the Cloud Run service in a region closer to the users.

Answer

Use a VPC connector to access resources in a VPC network.

Question 7

Which THREE are valid methods for authenticating a user or service when deploying a Cloud Function via the Google Cloud SDK? (Choose 3)

Accepted Answer

Using a user account with 'gcloud auth login'. 'gcloud auth login' authenticates a user account via OAuth 2.0, which is a valid method for deploying Cloud Functions. The Google Cloud SDK uses the user's credentials to authorize API calls, including deployments, making this a standard authentication approach for interactive or user-driven workflows.

Answer

Using an API key

Answer

Using an OAuth 2.0 client ID

Question 8

Which TWO statements about Cloud Run for Anthos are correct? (Choose 2)

Accepted Answer

Cloud Run for Anthos allows users to autoscale their containerized applications without worrying about underlying GKE nodes.. Cloud Run for Anthos leverages the Knative Serving autoscaler to automatically scale container instances up or down based on incoming request traffic, including scaling to zero when idle. This autoscaling operates at the pod level within the GKE cluster, abstracting away the underlying node management from the user.

Answer

Cloud Run for Anthos is a multi-region service by default.

Answer

Cloud Run for Anthos supports only HTTP requests, not gRPC.

Answer

Cloud Run for Anthos requires you to bring your own load balancer.

Question 9

A developer runs the command above and receives the error. The developer has just been granted the 'roles/cloudbuild.builds.editor' role on the project. What is the most likely reason for the permission error?

Accepted Answer

The Cloud Build API is not enabled for the project.. The error occurs because the Cloud Build API has not been enabled for the project. Even with the 'roles/cloudbuild.builds.editor' IAM role, the Cloud Build service itself must be explicitly enabled via the Google Cloud Console or using the `gcloud services enable cloudbuild.googleapis.com` command. Without enabling the API, any attempt to run a build will fail with a permission error, as the service is not available to process the request.

Answer

The project ID 'my-project' does not exist or the developer typed it incorrectly.

Answer

The container registry (gcr.io) is incorrect; should use us.gcr.io.

Answer

The developer is using the wrong region; Cloud Build must be enabled per region.

Question 10

A developer deployed the Kubernetes Deployment shown. The application takes about 45 seconds to fully initialize and respond on the /healthz endpoint. What problem will occur with this configuration?

Accepted Answer

The liveness probe will start too early and cause the pod to be restarted before it becomes ready.. The liveness probe has an initialDelaySeconds of 30 seconds, which is less than the application's initialization time of 45 seconds. Therefore, the liveness probe will start checking the /healthz endpoint at 30 seconds, fail, and Kubernetes will restart the pod before it becomes ready. The readiness probe does not prevent the liveness probe from running and causing restarts.

Answer

The readiness probe will never succeed, and the pod will be removed from service.

Answer

The deployment will not create any pods because of a syntax error.

Answer

The pod will be marked ready immediately because the readiness probe uses the same endpoint as liveness.

Question 11

A developer runs the command above. What is the effect of the --promote flag in this deployment?

Accepted Answer

It causes the new version (v2) to receive 100% of traffic after deployment.. The --promote flag in a Google Cloud App Engine deployment command (gcloud app deploy --promote) causes the newly deployed version (v2) to immediately receive 100% of traffic, effectively making it the default serving version. This is the standard behavior unless the --no-promote flag is explicitly used to keep traffic on the previous version.

Answer

It creates a new default service version with split traffic.

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It promotes the previous version to receive traffic.

Answer

It enables automatic scaling for the new version.

Question 12

You deployed a microservice on Cloud Run. Users report intermittent 503 errors. The service uses Cloud SQL with connection pooling. What is the most likely cause?

Accepted Answer

The connection pool is drained due to CPU throttling on Cloud Run.. When Cloud Run CPU throttling occurs (e.g., during cold starts or when the instance is processing requests beyond its allocated CPU), the connection pool can become drained because existing connections are held open while new requests cannot be processed. This leads to intermittent 503 errors as the service cannot establish new database connections or respond to incoming requests in time. Connection pooling does not protect against CPU throttling; it only manages database connections efficiently.

Answer

The service is not using a VPC connector for Cloud SQL access.

Answer

The Cloud SQL auth proxy is not configured.

Answer

The Cloud Run service name is not resolvable via Cloud DNS.

Question 13

A company is migrating a monolithic Java application to Cloud Run. The application takes 10 minutes to start. What is the best deployment approach?

Accepted Answer

Optimize the Java application to start within 10 minutes and use startup CPU boost.. Cloud Run allows a maximum container startup time of 10 minutes (600 seconds) by default, and the startup CPU boost feature temporarily allocates additional CPU during startup to accelerate initialization. By optimizing the application to start within this limit and enabling startup CPU boost, the company can directly address the cold start issue without changing the deployment platform or architecture.

Answer

Migrate to App Engine Flexible Environment.

Answer

Use a custom runtime with a cold start optimization.

Answer

Increase the memory limit to 4 GB.

Question 14

You are deploying a stateful application to GKE. The deployment fails with an error: 'pods failed to fit in any node due to insufficient CPU'. The cluster has 3 nodes with 4 vCPUs each. The deployment requests 2 vCPUs per pod with 5 replicas. What is the most likely issue?

Accepted Answer

Other workloads or system components are consuming CPU resources.. The cluster has 3 nodes × 4 vCPUs = 12 vCPUs total capacity. The deployment requests 5 pods × 2 vCPUs = 10 vCPUs, which is within the total capacity. However, the error indicates that the pods cannot be scheduled due to insufficient CPU. This is most likely because other workloads (e.g., system components, DaemonSets, or other deployments) are consuming CPU on the nodes, reducing the available CPU below what is required. Option A is incorrect because the cluster autoscaler would only add nodes if there is insufficient total capacity, but here the capacity exists but is consumed. Option B is incorrect because missing resource limits would not cause CPU insufficiency; it would allow pods to consume more but not prevent scheduling. Option D is incorrect because the error explicitly mentions insufficient CPU, not taints or tolerations. Therefore, option C is the most likely cause.

Answer

The cluster autoscaler is not enabled.

Answer

The deployment does not specify resource limits.

Answer

The nodes have taints that prevent pod scheduling.

Question 15

You need to deploy a critical update to a production service on GKE with zero downtime. Which deployment strategy should you use?

Accepted Answer

Blue/green deployment using a Kubernetes Service and label selector. Blue/green deployment creates two identical environments (blue and green) and switches traffic atomically by updating the Kubernetes Service's label selector to point to the new version. This ensures zero downtime because the old version remains fully serving until the new version is verified, and traffic cutover is instantaneous with no overlapping broken requests.

Answer

Recreate strategy

Answer

Canary deployment with 10% traffic

Answer

Rolling update with maxSurge=25%, maxUnavailable=25%