testNGテストで簡単な同時テストができます

import org.testng.annotations.Test;

@SpringBootTest(classes = MyServiceTest.TestApplication.class, properties = {"spring.profiles.active=dev"})
public class MyServiceTest extends AbstractTransactionalTestNGSpringContextTests {

    @Test(invocationCount = 10,threadPoolSize = 5)
    public void updateProcess() throws Exception {

        System.out.println("test");

    }

    @SpringBootApplication
    @ComponentScan(value = {"com.my.foo"})
    public static class TestApplication {
    }
}

一般テスト

@SpringBootTest(classes = SensiTest.TestApplication.class )
@ActiveProfiles("dev")
@RunWith(SpringRunner.class)
public class SensiTest {
 //testing...

    @SpringBootApplication
    @ComponentScan(value = {"com.my.foo"})
    public static class TestApplication {
    }
}