Android parallel testing with Selenium Grid and Docker

I know that this topic was brought up many times, but still I cannot get it.

I have the following docker-compose file:

version: '2'

services:
  # Selenium hub
  selenium_hub:
    image: selenium/hub
    container_name: selenium-hub
    ports:
      - 4444:4444

  # Appium Docker Android
  appium_android_device:
    image: appium/appium
    container_name: appium-real-device
    ports:
    - 4723:4723
    depends_on:
      - selenium_hub
    privileged: true
    volumes:
      - /dev/bus/usb:/dev/bus/usb
      - ~/.android:/root/.android
    environment:
      - CONNECT_TO_GRID=true
      - SELENIUM_HOST=selenium_hub

My OS is Ubuntu. Works fine, my android devices are added to the Selenium Grid.

BUT I do not understand what should I do from this point.

When I launch my tests, they run only on one device. Should I apply multithreading or something in my code? I thought Selenium Grid will take care of parallel execution.

My Java setup:

        DesiredCapabilities capabilities = new DesiredCapabilities();

        capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "Android");
        capabilities.setCapability(MobileCapabilityType.FULL_RESET, false);
        capabilities.setCapability(MobileCapabilityType.NO_RESET, true); 
        capabilities.setCapability(MobileCapabilityType.NEW_COMMAND_TIMEOUT, 10000);
        capabilities.setCapability(MobileCapabilityType.AUTOMATION_NAME, "uiAutomator2");
        capabilities.setCapability("appPackage", "com.some.app.package");

        capabilities.setCapability("appActivity", "com.some.MainActivity");

        AndroidDriver driver = new AndroidDriver<>(new URL("http://127.0.0.1:4444/wd/hub"), capabilities);

pouvez vous partager ton code avec nous pour qu’on puisse comprendre car appareil mobile ne s’affiche pas sur selenium grid