problem regarding running .xml file in TestNG for parallel tests

[abhi005]

when i am trying to run parallel tests for wikipedia page with the help of .xml file in TestNG, its only
working for Firefox..and giving Exception for Chrome.kindly help me to resolve this problem.
below is details of Exception

FAILED CONFIGURATION: @BeforeTest launchbrowser("Chrome")
java.lang.IllegalStateException: The path to the driver executable must be set by the webdriver.chrome.driver system property; for more information, see http://code.google.com/p/selenium/wiki/ChromeDriver. The latest version can be downloaded from http://chromedriver.storage.googleapis.com/index.html
        at com.google.common.base.Preconditions.checkState(Preconditions.java:197)
        at org.openqa.selenium.remote.service.DriverService.findExecutable(DriverService.java:110)
        at org.openqa.selenium.chrome.ChromeDriverService.access$0(ChromeDriverService.java:1)
        at org.openqa.selenium.chrome.ChromeDriverService$Builder.findDefaultExecutable(ChromeDriverService.java:118)
        at org.openqa.selenium.remote.service.DriverService$Builder.build(DriverService.java:291)
        at org.openqa.selenium.chrome.ChromeDriverService.createDefaultService(ChromeDriverService.java:82)
        at org.openqa.selenium.chrome.ChromeDriver.<init>(ChromeDriver.java:117)
        at com.selenium.SelTestCase.launchbrowser(SelTestCase.java:24)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
        at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:564)
        at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:213)
        at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:138)
        at org.testng.TestRunner.beforeRun(TestRunner.java:641)
        at org.testng.TestRunner.run(TestRunner.java:609)
        at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
        at org.testng.SuiteRunner.access$000(SuiteRunner.java:37)
        at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:368)
        at org.testng.internal.thread.ThreadUtil$2.call(ThreadUtil.java:64)
        at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)

SKIPPED CONFIGURATION: @AfterTest closebrowser
SKIPPED: wikipedia

===============================================
    wiki in Chrome
    Tests run: 1, Failures: 0, Skips: 1
    Configuration Failures: 1, Skips: 1
===============================================

[softwaretestingforum]

It seem from error message that chrome binary is missing

The path to the driver executable must be set by the webdriver.chrome.driver system property; for more information, see http://code.google.com/p/selenium/wiki/ChromeDriver. The latest version can be downloaded from http://chromedriver.storage.googleapis.com/index.html

You can download the chrome driver from here - https://sites.google.com/a/chromium.org/chromedriver/downloads

and start selenium server with following command -

java -jar selenium-server-standalone-${SELENIUMVERSION}.jar -role hub & java -jar selenium-server-standalone-${SELENIUMVERSION}.jar -role node  -hub http://localhost:4444/grid/register -Dwebdriver.chrome.driver=<your path>chromedriver

replace - ${SELENIUMVERSION} with the version of selenium you are using( I suppose latest version is 2.45) and replace "<your path>chromedriver" with the path where you have downloaded chrome binary

Hope this helps