Running parallel test in TestNG Appium Selenium

Question

I have windows 7 which is connected to two android devices and I am using Selenium and Appium to automate an App but not able to run the test simultaneously in both the devices. below is the code I am using along with contents from testng.xml. let me know where I am wrong. The below code runs fine but it installs the app on first device then on second device what I want to acheive is install the app simultaneously on both the devices. Any help appreciated.

package ca.automation.com;

import org.testng.annotations.Test;

import com.relevantcodes.extentreports.ExtentReports;
import com.relevantcodes.extentreports.ExtentTest;
import com.relevantcodes.extentreports.LogStatus;

import io.appium.java_client.android.AndroidDriver;

import org.testng.annotations.BeforeSuite;
import org.testng.annotations.BeforeTest;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;
import java.util.concurrent.TimeUnit;

import org.junit.Assert;
import org.openqa.selenium.By;
import org.openqa.selenium.NoSuchElementException;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;

public class StackOverflow {

    WebDriver driver1;
    WebDriver driver2;
//  ExtentReports report;
//  ExtentTest logger;
//  Boolean present;
    File app = new File("App\\app_US_IT_Ananta.apk");


    @BeforeSuite
    public void startReport(){
//      report=new ExtentReports("C:\\Anuj\\MobileAppResults.html");

    }

    @Test (priority =0)
    public void installapp() {
        //      logger=report.startTest("VerifyAppInstalltion");

        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability("udid", "1015fadb1a274005");
        //      capabilities.setCapability("udid", "ee92ba92");
        capabilities.setCapability("deviceName","Android Emulator");
        capabilities.setCapability("platformVersion", "4.4");
        capabilities.setCapability("autoAcceptAlerts", true);
        capabilities.setCapability("app", app.getAbsolutePath());
        try {
            driver1 = new AndroidDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

    @Test (priority =0)
    public void installapp1() {
        DesiredCapabilities capabilities1 = new DesiredCapabilities();
        capabilities1.setCapability("udid", "ee92ba92");
        capabilities1.setCapability("deviceName","Android Emulator");
        capabilities1.setCapability("platformVersion", "4.4");
        capabilities1.setCapability("autoAcceptAlerts", true);
        capabilities1.setCapability("app", app.getAbsolutePath());
        try {
            driver2 = new AndroidDriver(new URL("http://127.0.0.1:4730/wd/hub"), capabilities1);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

}

Testng.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Suite" parallel="tests" thread-count="2">
  <test name="Test">
    <classes>
      <class name="ca.automation.com.StackOverflow"/>
    </classes>
  </test> <!-- Test -->

Answer 1

Change parallel="tests" to parallel="methods" because you have to execute the methods in parallel, as its in your case.

Also, running tests in parallel wont be exactly 100% simultaneous execution. There would be some lag between execution in both devices. Try out a complete script with few more additional steps. That way we can easily make out that the tests are running simultaneously.