[Improvement][remote] set connect time out (#3670)

dolphinscheduler-remote/src/main/java/org/apache/dolphinscheduler/remote/NettyRemotingClient.java

@@ -159,6 +159,7 @@ public class NettyRemotingClient {
             .option(ChannelOption.TCP_NODELAY, clientConfig.isTcpNoDelay())
             .option(ChannelOption.SO_SNDBUF, clientConfig.getSendBufferSize())
             .option(ChannelOption.SO_RCVBUF, clientConfig.getReceiveBufferSize())
+            .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, clientConfig.getConnectTimeoutMillis())
             .handler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {

dolphinscheduler-remote/src/main/java/org/apache/dolphinscheduler/remote/config/NettyClientConfig.java

@@ -14,6 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.apache.dolphinscheduler.remote.config;
 
 import org.apache.dolphinscheduler.remote.utils.Constants;
@@ -48,6 +49,11 @@ public class NettyClientConfig {
      */
     private int receiveBufferSize = 65535;
 
+    /**
+     * connect timeout millis
+     */
+    private int connectTimeoutMillis = 3000;
+
     public int getWorkerThreads() {
         return workerThreads;
     }
@@ -88,4 +94,11 @@ public class NettyClientConfig {
         this.receiveBufferSize = receiveBufferSize;
     }
 
+    public int getConnectTimeoutMillis() {
+        return connectTimeoutMillis;
+    }
+
+    public void setConnectTimeoutMillis(int connectTimeoutMillis) {
+        this.connectTimeoutMillis = connectTimeoutMillis;
+    }
 }