switch server optimize and loader balance base on max client count (#…

…3420)

* Add gprc support-> authentication on client

* Add gprc support-> optimize switch server and submit loader balance base on up limit clients count.

api/src/main/java/com/alibaba/nacos/api/remote/ResponseRegistry.java

@@ -28,6 +28,7 @@
 import com.alibaba.nacos.api.naming.remote.response.QueryServiceResponse;
 import com.alibaba.nacos.api.naming.remote.response.SubscribeServiceResponse;
 import com.alibaba.nacos.api.remote.response.ConnectResetResponse;
+import com.alibaba.nacos.api.remote.response.ConnectionUnregisterResponse;
 import com.alibaba.nacos.api.remote.response.HeartBeatResponse;
 import com.alibaba.nacos.api.remote.response.ResponseTypeConstants;
 import com.alibaba.nacos.api.remote.response.UnKnowResponse;
@@ -51,6 +52,7 @@ public class ResponseRegistry {
         REGISTRY_RESPONSES.put(ResponseTypeConstants.HEART_BEAT, HeartBeatResponse.class);
         REGISTRY_RESPONSES.put(ResponseTypeConstants.CONNECT_SWITCH, ConnectResetResponse.class);
         REGISTRY_RESPONSES.put(ResponseTypeConstants.UNKNOW, UnKnowResponse.class);
+        REGISTRY_RESPONSES.put(ResponseTypeConstants.CONNECION_UNREGISTER, ConnectionUnregisterResponse.class);
 
         //config response registry
         REGISTRY_RESPONSES.put(ConfigResponseTypeConstants.CONFIG_CHANGE, ConfigChangeListenResponse.class);

api/src/main/java/com/alibaba/nacos/api/remote/connection/Connection.java

@@ -26,6 +26,40 @@
  */
 public abstract class Connection {
 
+    public static final String HEALTHY = "healthy";
+
+    public static final String UNHEALTHY = "unhealthy";
+
+    public static final String SWITCHING = "swtiching";
+
+    private String status;
+
+    public boolean isHealthy() {
+        return HEALTHY.equals(this.status);
+    }
+
+    public boolean isSwitching() {
+        return HEALTHY.equals(this.status);
+    }
+
+    /**
+     * Getter method for property <tt>status</tt>.
+     *
+     * @return property value of status
+     */
+    public String getStatus() {
+        return status;
+    }
+
+    /**
+     * Setter method for property <tt>status</tt>.
+     *
+     * @param status value to be assigned to property status
+     */
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
     private final ConnectionMetaInfo metaInfo;
 
     public Connection(ConnectionMetaInfo metaInfo) {
@@ -53,6 +87,7 @@ public void freshActiveTime() {
 
     /**
      * return last active time, include request occurs and.
+     *
      * @return
      */
     public long getLastActiveTimestamp() {

api/src/main/java/com/alibaba/nacos/api/remote/exception/ConnectionAlreadyClosedException.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.api.remote.exception;
+
+/**
+ * connection already closed exception.
+ *
+ * @author liuzunfei
+ * @version $Id: ConnectionAlreadyClosedException.java, v 0.1 2020年07月22日 7:28 PM liuzunfei Exp $
+ */
+public class ConnectionAlreadyClosedException extends RemoteException {
+
+    private static final int CONNECTION_ALREADY_CLOSED = 600;
+
+    public ConnectionAlreadyClosedException() {
+        super(CONNECTION_ALREADY_CLOSED);
+    }
+
+    public ConnectionAlreadyClosedException(Throwable throwable) {
+        super(CONNECTION_ALREADY_CLOSED, throwable);
+    }
+}

api/src/main/java/com/alibaba/nacos/api/remote/exception/RemoteException.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.api.remote.exception;
+
+import com.alibaba.nacos.api.exception.runtime.NacosRuntimeException;
+
+/**
+ * super exception in remote module.
+ *
+ * @author liuzunfei
+ * @version $Id: RemoteException.java, v 0.1 2020年07月22日 7:24 PM liuzunfei Exp $
+ */
+public class RemoteException extends NacosRuntimeException {
+
+    public RemoteException(int errorCode) {
+        super(errorCode);
+    }
+
+    public RemoteException(int errorCode, Throwable throwable) {
+        super(errorCode, throwable);
+    }
+}

api/src/main/java/com/alibaba/nacos/api/remote/request/HeartBeatRequest.java

@@ -18,18 +18,15 @@
 
 /**
  * HeartBeatRequest.
+ *
  * @author liuzunfei
  * @version $Id: HeartBeatRequest.java, v 0.1 2020年07月14日 11:38 AM liuzunfei Exp $
  */
-public class HeartBeatRequest extends Request {
-
+public class HeartBeatRequest extends InternalRequest {
+    
     @Override
     public String getType() {
         return RequestTypeConstants.HEART_BEAT;
     }
-
-    @Override
-    public String getModule() {
-        return "internal";
-    }
+
 }

api/src/main/java/com/alibaba/nacos/api/remote/request/InternalRequest.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.api.remote.request;
+
+/**
+ * internal request .
+ *
+ * @author liuzunfei
+ * @version $Id: InternalRequest.java, v 0.1 2020年07月22日 8:33 PM liuzunfei Exp $
+ */
+public abstract class InternalRequest extends Request {
+
+    @Override
+    public String getModule() {
+        return "internal";
+    }
+}

api/src/main/java/com/alibaba/nacos/api/remote/request/Request.java

@@ -16,13 +16,59 @@
 
 package com.alibaba.nacos.api.remote.request;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * Request.
  *
  * @author liuzunfei
  */
 public abstract class Request {
 
+    private final Map<String, String> headers = new HashMap<String, String>();
+
+    /**
+     * put header.
+     *
+     * @param key   key of value.
+     * @param value value.
+     */
+    public void putHeader(String key, String value) {
+        headers.put(key, value);
+    }
+
+    /**
+     * put headers .
+     *
+     * @param headers headers to put.
+     */
+    public void putAllHeader(Map<String, String> headers) {
+        headers.putAll(headers);
+    }
+
+    /**
+     * get a header value .
+     *
+     * @param key key of value.
+     * @return return value of key. return null if not exist.
+     */
+    public String getHeader(String key) {
+        return headers.get(key);
+    }
+
+    /**
+     * get a header value of defaut value.
+     *
+     * @param key          key of value.
+     * @param defaultValue default value if key is not exist.
+     * @return return final value.
+     */
+    public String getHeader(String key, String defaultValue) {
+        String value = headers.get(key);
+        return (value == null) ? defaultValue : value;
+    }
+
     /**
      * Getter method for property <tt>type</tt>.
      *
@@ -37,4 +83,12 @@ public abstract class Request {
      */
     public abstract String getModule();
 
+    /**
+     * Getter method for property <tt>headers</tt>.
+     *
+     * @return property value of headers
+     */
+    public Map<String, String> getHeaders() {
+        return headers;
+    }
 }

api/src/main/java/com/alibaba/nacos/api/remote/request/RequestTypeConstants.java

@@ -26,4 +26,6 @@ public class RequestTypeConstants {
 
     public static final String HEART_BEAT = "HEART_BEAT";
 
+    public static final String SERVER_CHECK = "SERVER_CHECK";
+
 }

api/src/main/java/com/alibaba/nacos/api/remote/request/ServerCheckRequest.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.api.remote.request;
+
+/**
+ * request to check server if unimpeded.
+ *
+ * @author liuzunfei
+ * @version $Id: ServerCheckRequest.java, v 0.1 2020年07月22日 8:32 PM liuzunfei Exp $
+ */
+public class ServerCheckRequest extends InternalRequest {
+
+    @Override
+    public String getType() {
+        return RequestTypeConstants.SERVER_CHECK;
+    }
+
+}

api/src/main/java/com/alibaba/nacos/api/remote/response/ConnectionUnregisterResponse.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.api.remote.response;
+
+/**
+ * response indicates that the connection of the request is unregisterd.
+ *
+ * @author liuzunfei
+ * @version $Id: ConnectionUnregisterResponse.java, v 0.1 2020年07月22日 8:44 PM liuzunfei Exp $
+ */
+public class ConnectionUnregisterResponse extends Response {
+
+    @Override
+    public String getType() {
+        return ResponseTypeConstants.CONNECION_UNREGISTER;
+    }
+}

api/src/main/java/com/alibaba/nacos/api/remote/response/ResponseTypeConstants.java

@@ -31,5 +31,9 @@ public class ResponseTypeConstants {
 
     public static final String UNKNOW = "UNKNOW";
 
+    public static final String SERVER_CHECK = "SERVER_CHECK";
+
+    public static final String CONNECION_UNREGISTER = "CONNECION_UNREGISTER";
+
 
 }

api/src/main/java/com/alibaba/nacos/api/remote/response/ServerCheckResponse.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.api.remote.response;
+
+/**
+ * response of server check.
+ *
+ * @author liuzunfei
+ * @version $Id: ServerCheckResponse.java, v 0.1 2020年07月22日 8:37 PM liuzunfei Exp $
+ */
+public class ServerCheckResponse extends Response {
+
+    @Override
+    public String getType() {
+        return ResponseTypeConstants.SERVER_CHECK;
+    }
+}

client/src/main/java/com/alibaba/nacos/client/remote/RpcClientStatus.java

@@ -27,7 +27,8 @@ public enum RpcClientStatus {
     INITED(1, "server list factory is ready,wait to start"),
     STARTING(2, "server list factory is ready,wait to start"),
     RUNNING(3, "client is running..."),
-    RE_CONNECTING(4, "reconnecting...");
+    SWITCHING_SERVER(5, "reconnecting...");
+
 
     int status;