Add Tear down for tests

Signed-off-by: Sooraj Sinha <[email protected]>

server/src/test/java/org/opensearch/cluster/routing/remote/RemoteRoutingTableServiceFactoryTests.java

@@ -16,6 +16,7 @@
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.threadpool.TestThreadPool;
 import org.opensearch.threadpool.ThreadPool;
+import org.junit.After;
 
 import java.util.function.Supplier;
 
@@ -27,6 +28,12 @@ public class RemoteRoutingTableServiceFactoryTests extends OpenSearchTestCase {
     Supplier<RepositoriesService> repositoriesService;
     private ThreadPool threadPool = new TestThreadPool(getClass().getName());
 
+    @After
+    public void teardown() throws Exception {
+        super.tearDown();
+        threadPool.shutdown();
+    }
+
     public void testGetServiceWhenRemoteRoutingDisabled() {
         Settings settings = Settings.builder().build();
         RemoteRoutingTableService service = RemoteRoutingTableServiceFactory.getService(
@@ -53,4 +60,5 @@ public void testGetServiceWhenRemoteRoutingEnabled() {
         );
         assertTrue(service instanceof InternalRemoteRoutingTableService);
     }
+
 }