Manuals / Selenium WebDriver / Ch 8

C · Test InfrastructureIntermediate50 min read

8. Selenium Grid awareness

Selenium WebDriver · 48 pages source format

Grid runs browsers on remote nodes — parallel cross-browser at scale. You may not run Grid locally, but enterprise interviews expect awareness.

What you'll learn

  • Hub and Node model
  • RemoteWebDriver
  • Docker Grid quickstart
  • Cloud grids (BrowserStack, Sauce Labs)

Grid architecture

Hub routes commands. Nodes run browsers. Client uses RemoteWebDriver pointing at hub URL.

Do this now

Draw hub-node diagram in GRID-NOTES.md.

Clear?

Docker Selenium Grid

selenium/standalone-chrome or docker-compose with hub + nodes — local Grid in minutes.

docker run -d -p 4444:4444 -p 7900:7900 --shm-size="2g" selenium/standalone-chrome:latest
# Python RemoteWebDriver
from selenium.webdriver import Remote
 driver = Remote(command_executor="http://localhost:4444", options=options)

Do this now

Run standalone-chrome container. Connect RemoteWebDriver to localhost:4444. Run one test.

Clear?

Cloud providers

BrowserStack, Sauce Labs, LambdaTest — capabilities object sets browser/OS. Know for resume/interview.

Do this now

Read one provider docs page. List capability keys for Chrome on Windows.

Clear?

When Grid vs local

Local for dev. Grid/cloud for CI parallel cross-browser. Document strategy in README.

Do this now

Write 1 paragraph: when your project would use Grid.

Clear?

Checklist