Selenium Server -

WebDriver driver = new RemoteWebDriver( new URL("http://localhost:4444"), new ChromeOptions() ); | Metric | Value/Note | |--------|-------------| | Max concurrent sessions per node | Default 1 per browser type (configurable) | | Protocol overhead | ~5-10ms per command over localhost; higher over network | | Scalability limit | ~100-200 nodes per hub in Selenium 3; Selenium 4 improves with event bus | | Browser launch time | Adds 1-3 seconds vs direct WebDriver |

java -jar selenium-server.jar hub

java -jar selenium-server.jar node --detect-drivers true selenium server

# Check grid status curl http://localhost:4444/status java -jar selenium-server.jar node --max-sessions 5 Run with Docker docker run -d -p 4444:4444 --name selenium-hub selenium/hub:4.10 docker run -d -p 5555:5555 --link selenium-hub selenium/node-chrome:4.10 new ChromeOptions() )