DUBBO-490 graceful shutdown :当注册中心尚未推送到客户端时，重连时不能报error级别日志。

重试连接报错时间距离上一次成功连接10秒内 则warn 否则error

git-svn-id: http://code.alibabatech.com/svn/dubbo/trunk@73 1a56cb94-b969-4eaa-88fa-be21384802f2

dubbo-common/src/main/java/com/alibaba/dubbo/common/Constants.java

@@ -225,6 +225,8 @@ public class Constants {
     
     public static final int          DEFAULT_RECONNECT_PERIOD       =  2000;
     
+    public static final String       SHUTDOWN_TIMEOUT_KEY           =  "shutdown.timeout";
+    
     public static final int          DEFAULT_SHUTDOWN_TIMEOUT       =  10000;
 
     public static final String       CHECK_KEY                      = "check";

dubbo-remoting/src/main/java/com/alibaba/dubbo/remoting/transport/AbstractClient.java

@@ -57,13 +57,20 @@ public abstract class AbstractClient extends AbstractEndpoint implements Client
     
     protected volatile ExecutorService executor;
     
-    private final boolean send_reconnect ;
+    private final boolean send_reconnect ;
+    
+    //the last successed connected time
+    private long lastConnectedTime = System.currentTimeMillis();
+    
+    private final int shutdown_timeout ;
     
     
     public AbstractClient(URL url, ChannelHandler handler) throws RemotingException {
         super(url, handler);
         
-        send_reconnect = url.getBooleanParameter(Constants.SEND_RECONNECT_KEY, false);
+        send_reconnect = url.getBooleanParameter(Constants.SEND_RECONNECT_KEY, false);
+        
+        shutdown_timeout = url.getIntParameter(Constants.SHUTDOWN_TIMEOUT_KEY, Constants.DEFAULT_SHUTDOWN_TIMEOUT);
         
         try {
             doOpen();
@@ -103,17 +110,23 @@ public abstract class AbstractClient extends AbstractEndpoint implements Client
      * init reconnect thread
      */
     private synchronized void initConnectStatusCheckCommand(){
-        //如果配置了 reconnect = false 则不尝试重连。
+        //reconnect=false to close reconnect 
         int reconnect = getReconnectParam(getUrl());
         if(reconnect > 0 && reconnectExecutorFuture == null){
-            Runnable connectStatusCheckCommand =  new Runnable() {
+            Runnable connectStatusCheckCommand =  new Runnable() {
+                String errorMsg = "Unexpected error occur at client reconnect";
                 public void run() {
                     try {
                         if (! isConnected()) {
-                            connect();//定时检查与消息发送时检测都要做。
+                            connect();
+                        }
+                    } catch (Throwable t) { 
+                        // wait registry sync provider list
+                        if (System.currentTimeMillis() - lastConnectedTime > shutdown_timeout){
+                            logger.warn(errorMsg, t);
+                        } else {
+                            logger.error(errorMsg, t);
                         }
-                    } catch (Throwable t) { // 防御性容错
-                        logger.error("Unexpected error occur at client reconnect", t);
                     }
                 }
             };
@@ -236,7 +249,8 @@ public abstract class AbstractClient extends AbstractEndpoint implements Client
                 throw new RemotingException(this, "Failed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName()
                                             + NetUtils.getLocalHost() + " using dubbo version " + Version.getVersion()
                                             + ", cause: Connect wait timeout: " + getTimeout() + "ms.");
-            }
+            }
+            lastConnectedTime = System.currentTimeMillis();
         } catch (RemotingException e) {
             throw e;
         } catch (Throwable e) {