Selenium Cloud Computing & Services 3 — Questions and Answers
Question 1: Which Selenium Grid 4 component acts as the entry point that accepts new session requests and routes them to available nodes?
- Distributor
- Router (Correct answer)
- Event Bus
- Session Map
Correct answer: Router
The Router is the front-door component that receives WebDriver commands and delegates them to the appropriate internal Grid components.
Question 2: A cloud Selenium test suite needs to run against a staging site accessible only inside a VPC. Which approach best enables this?
- Use a public Selenium SaaS grid without any tunneling
- Deploy the Selenium Grid nodes inside the same VPC as the staging site (Correct answer)
- Disable VPC firewall rules entirely
- Use only local WebDriver instances
Correct answer: Deploy the Selenium Grid nodes inside the same VPC as the staging site
Deploying Grid nodes inside the VPC gives them direct network access to internal staging URLs without exposing them to the internet.
Question 3: Which Google Cloud service is commonly used to run containerized Selenium Grid nodes as serverless jobs without managing VM infrastructure?
- Google Cloud SQL
- Google Cloud Run (Correct answer)
- Google BigQuery
- Google Cloud DNS
Correct answer: Google Cloud Run
Cloud Run executes containers on demand and scales to zero when idle, making it cost-efficient for running Selenium node containers.
Question 4: What Helm chart is officially provided by the Selenium project for deploying Selenium Grid on Kubernetes?
- selenium/selenium-server
- docker-selenium/chart
- seleniumhq/selenium-grid (Correct answer)
- selenium/k8s-grid
Correct answer: seleniumhq/selenium-grid
The official Helm chart is maintained at seleniumhq/selenium-grid and supports deploying Hub, Router, Distributor, and nodes on Kubernetes.
Question 5: In cloud-based parallel Selenium testing, what is the role of a 'session queue'?
- Stores browser screenshots for later review
- Holds pending WebDriver session requests until a node becomes available (Correct answer)
- Manages user login sessions across tests
- Queues DOM events for replay
Correct answer: Holds pending WebDriver session requests until a node becomes available
The session queue buffers incoming new-session requests so they are not dropped when all nodes are busy, ensuring orderly dispatch.
Question 6: Which Azure service provides a fully managed Kubernetes cluster suitable for hosting Selenium Grid?
- Azure Blob Storage
- Azure Kubernetes Service (AKS) (Correct answer)
- Azure Functions
- Azure Logic Apps
Correct answer: Azure Kubernetes Service (AKS)
AKS manages the Kubernetes control plane for you, letting teams focus on deploying Selenium Grid workloads rather than cluster administration.
Question 7: What does 'node-max-sessions' control in a Selenium Grid node configuration?
- The maximum number of Grid Hubs allowed
- How many concurrent browser sessions a single node will accept (Correct answer)
- The timeout before a node is deregistered
- The maximum script execution time per test
Correct answer: How many concurrent browser sessions a single node will accept
node-max-sessions caps concurrency on a single node to prevent resource exhaustion from too many simultaneous browser instances.
Selenium Cloud Computing & Services 3
Which Selenium Grid 4 component acts as the entry point that accepts new session requests and routes them to available nodes?