Hi Rahul, threadPoolSize tells the TestNG to form a thread pool to run the test method through multiple threads. Though this attribute is ignored if invocationCount is not specified. In this example, the method testCase1 will be invoked from three different threads:
@Test(threadPoolSize = 3, <code class="plain">invocationCount = </code><code class="value">10</code>)
public void testCase1(){}