Config and log enhancement for cluster token client

- Refactor token client common config and assign config
- Log enhancement when transport to token server failed
- Add `getState` method to `ClusterTokenClient` interface

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/DefaultClusterTokenClient.java

@@ -19,11 +19,12 @@ import java.util.Collection;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import com.alibaba.csp.sentinel.cluster.ClusterConstants;
+import com.alibaba.csp.sentinel.cluster.ClusterErrorMessages;
 import com.alibaba.csp.sentinel.cluster.ClusterTransportClient;
 import com.alibaba.csp.sentinel.cluster.TokenResult;
 import com.alibaba.csp.sentinel.cluster.TokenResultStatus;
 import com.alibaba.csp.sentinel.cluster.TokenServerDescriptor;
-import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfig;
+import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientAssignConfig;
 import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfigManager;
 import com.alibaba.csp.sentinel.cluster.client.config.ServerChangeObserver;
 import com.alibaba.csp.sentinel.cluster.log.ClusterClientStatLogUtil;
@@ -51,14 +52,14 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
     public DefaultClusterTokenClient() {
         ClusterClientConfigManager.addServerChangeObserver(new ServerChangeObserver() {
             @Override
-            public void onRemoteServerChange(ClusterClientConfig clusterClientConfig) {
-                changeServer(clusterClientConfig);
+            public void onRemoteServerChange(ClusterClientAssignConfig assignConfig) {
+                changeServer(assignConfig);
             }
         });
         initNewConnection();
     }
 
-    private boolean serverEqual(TokenServerDescriptor descriptor, ClusterClientConfig config) {
+    private boolean serverEqual(TokenServerDescriptor descriptor, ClusterClientAssignConfig config) {
         if (descriptor == null || config == null) {
             return false;
         }
@@ -84,7 +85,7 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
         }
     }
 
-    private void changeServer(/*@Valid*/ ClusterClientConfig config) {
+    private void changeServer(/*@Valid*/ ClusterClientAssignConfig config) {
         if (serverEqual(serverDescriptor, config)) {
             return;
         }
@@ -93,7 +94,7 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
                 transportClient.stop();
             }
             // Replace with new, even if the new client is not ready.
-            this.transportClient = new NettyTransportClient(config);
+            this.transportClient = new NettyTransportClient(config.getServerHost(), config.getServerPort());
             this.serverDescriptor = new TokenServerDescriptor(config.getServerHost(), config.getServerPort());
             startClientIfScheduled();
             RecordLog.info("[DefaultClusterTokenClient] New client created: " + serverDescriptor);
@@ -132,6 +133,14 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
         stopClientIfStarted();
     }
 
+    @Override
+    public int getState() {
+        if (transportClient == null) {
+            return ClientConstants.CLIENT_STATUS_OFF;
+        }
+        return transportClient.isReady() ? ClientConstants.CLIENT_STATUS_STARTED : ClientConstants.CLIENT_STATUS_OFF;
+    }
+
     @Override
     public TokenServerDescriptor currentServer() {
         return serverDescriptor;
@@ -146,7 +155,9 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
             .setFlowId(flowId).setPriority(prioritized);
         ClusterRequest<FlowRequestData> request = new ClusterRequest<>(ClusterConstants.MSG_TYPE_FLOW, data);
         try {
-            return sendTokenRequest(request);
+            TokenResult result = sendTokenRequest(request);
+            logForResult(result);
+            return result;
         } catch (Exception ex) {
             ClusterClientStatLogUtil.log(ex.getMessage());
             return new TokenResult(TokenResultStatus.FAIL);
@@ -162,16 +173,31 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
             .setFlowId(flowId).setParams(params);
         ClusterRequest<ParamFlowRequestData> request = new ClusterRequest<>(ClusterConstants.MSG_TYPE_PARAM_FLOW, data);
         try {
-            return sendTokenRequest(request);
+            TokenResult result = sendTokenRequest(request);
+            logForResult(result);
+            return result;
         } catch (Exception ex) {
             ClusterClientStatLogUtil.log(ex.getMessage());
             return new TokenResult(TokenResultStatus.FAIL);
         }
     }
 
+    private void logForResult(TokenResult result) {
+        switch (result.getStatus()) {
+            case TokenResultStatus.NO_RULE_EXISTS:
+                ClusterClientStatLogUtil.log(ClusterErrorMessages.NO_RULES_IN_SERVER);
+                break;
+            case TokenResultStatus.TOO_MANY_REQUEST:
+                ClusterClientStatLogUtil.log(ClusterErrorMessages.TOO_MANY_REQUESTS);
+                break;
+            default:
+        }
+    }
+
     private TokenResult sendTokenRequest(ClusterRequest request) throws Exception {
         if (transportClient == null) {
-            RecordLog.warn("[DefaultClusterTokenClient] Client not created, please check your config for cluster client");
+            RecordLog.warn(
+                "[DefaultClusterTokenClient] Client not created, please check your config for cluster client");
             return clientFail();
         }
         ClusterResponse response = transportClient.sendRequest(request);

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/config/ClusterClientAssignConfig.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 1999-2018 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.csp.sentinel.cluster.client.config;
+
+/**
+ * @author Eric Zhao
+ * @since 1.4.1
+ */
+public class ClusterClientAssignConfig {
+
+    private String serverHost;
+    private Integer serverPort;
+
+    public ClusterClientAssignConfig() {}
+
+    public ClusterClientAssignConfig(String serverHost, Integer serverPort) {
+        this.serverHost = serverHost;
+        this.serverPort = serverPort;
+    }
+
+    public String getServerHost() {
+        return serverHost;
+    }
+
+    public ClusterClientAssignConfig setServerHost(String serverHost) {
+        this.serverHost = serverHost;
+        return this;
+    }
+
+    public Integer getServerPort() {
+        return serverPort;
+    }
+
+    public ClusterClientAssignConfig setServerPort(Integer serverPort) {
+        this.serverPort = serverPort;
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        return "ClusterClientAssignConfig{" +
+            "serverHost='" + serverHost + '\'' +
+            ", serverPort=" + serverPort +
+            '}';
+    }
+}

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/config/ClusterClientConfig.java

@@ -21,55 +21,21 @@ package com.alibaba.csp.sentinel.cluster.client.config;
  */
 public class ClusterClientConfig {
 
-    private String serverHost;
-    private int serverPort;
+    private Integer requestTimeout;
 
-    private int requestTimeout;
-    private int connectTimeout;
-
-    public String getServerHost() {
-        return serverHost;
-    }
-
-    public ClusterClientConfig setServerHost(String serverHost) {
-        this.serverHost = serverHost;
-        return this;
-    }
-
-    public int getServerPort() {
-        return serverPort;
-    }
-
-    public ClusterClientConfig setServerPort(int serverPort) {
-        this.serverPort = serverPort;
-        return this;
-    }
-
-    public int getRequestTimeout() {
+    public Integer getRequestTimeout() {
         return requestTimeout;
     }
 
-    public ClusterClientConfig setRequestTimeout(int requestTimeout) {
+    public ClusterClientConfig setRequestTimeout(Integer requestTimeout) {
         this.requestTimeout = requestTimeout;
         return this;
     }
 
-    public int getConnectTimeout() {
-        return connectTimeout;
-    }
-
-    public ClusterClientConfig setConnectTimeout(int connectTimeout) {
-        this.connectTimeout = connectTimeout;
-        return this;
-    }
-
     @Override
     public String toString() {
         return "ClusterClientConfig{" +
-            "serverHost='" + serverHost + '\'' +
-            ", serverPort=" + serverPort +
-            ", requestTimeout=" + requestTimeout +
-            ", connectTimeout=" + connectTimeout +
+            "requestTimeout=" + requestTimeout +
             '}';
     }
 }

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/config/ClusterClientConfigManager.java

@@ -37,23 +37,54 @@ public final class ClusterClientConfigManager {
      */
     private static volatile String serverHost = null;
     private static volatile int serverPort = ClusterConstants.DEFAULT_CLUSTER_SERVER_PORT;
+
     private static volatile int requestTimeout = ClusterConstants.DEFAULT_REQUEST_TIMEOUT;
+    private static volatile int connectTimeout = ClusterConstants.DEFAULT_CONNECT_TIMEOUT_MILLIS;
+
+    private static final PropertyListener<ClusterClientConfig> CONFIG_PROPERTY_LISTENER
+        = new ClientConfigPropertyListener();
+    private static final PropertyListener<ClusterClientAssignConfig> ASSIGN_PROPERTY_LISTENER
+        = new ClientAssignPropertyListener();
 
-    private static final PropertyListener<ClusterClientConfig> PROPERTY_LISTENER = new ClientConfigPropertyListener();
-    private static SentinelProperty<ClusterClientConfig> currentProperty = new DynamicSentinelProperty<>();
+    private static SentinelProperty<ClusterClientConfig> clientConfigProperty = new DynamicSentinelProperty<>();
+    private static SentinelProperty<ClusterClientAssignConfig> clientAssignProperty = new DynamicSentinelProperty<>();
 
     private static final List<ServerChangeObserver> SERVER_CHANGE_OBSERVERS = new ArrayList<>();
 
     static {
-        currentProperty.addListener(PROPERTY_LISTENER);
+        bindPropertyListener();
+    }
+
+    private static void bindPropertyListener() {
+        removePropertyListener();
+        clientAssignProperty.addListener(ASSIGN_PROPERTY_LISTENER);
+        clientConfigProperty.addListener(CONFIG_PROPERTY_LISTENER);
     }
 
-    public static void register2Property(SentinelProperty<ClusterClientConfig> property) {
-        synchronized (PROPERTY_LISTENER) {
-            RecordLog.info("[ClusterClientConfigManager] Registering new property to cluster client config manager");
-            currentProperty.removeListener(PROPERTY_LISTENER);
-            property.addListener(PROPERTY_LISTENER);
-            currentProperty = property;
+    private static void removePropertyListener() {
+        clientAssignProperty.removeListener(ASSIGN_PROPERTY_LISTENER);
+        clientConfigProperty.removeListener(CONFIG_PROPERTY_LISTENER);
+    }
+
+    public static void registerServerAssignProperty(SentinelProperty<ClusterClientAssignConfig> property) {
+        AssertUtil.notNull(property, "property cannot be null");
+        synchronized (ASSIGN_PROPERTY_LISTENER) {
+            RecordLog.info("[ClusterClientConfigManager] Registering new server assignment property to cluster "
+                + "client config manager");
+            clientAssignProperty.removeListener(ASSIGN_PROPERTY_LISTENER);
+            property.addListener(ASSIGN_PROPERTY_LISTENER);
+            clientAssignProperty = property;
+        }
+    }
+
+    public static void registerClientConfigProperty(SentinelProperty<ClusterClientConfig> property) {
+        AssertUtil.notNull(property, "property cannot be null");
+        synchronized (CONFIG_PROPERTY_LISTENER) {
+            RecordLog.info("[ClusterClientConfigManager] Registering new global client config property to "
+                + "cluster client config manager");
+            clientConfigProperty.removeListener(CONFIG_PROPERTY_LISTENER);
+            property.addListener(CONFIG_PROPERTY_LISTENER);
+            clientConfigProperty = property;
         }
     }
 
@@ -68,54 +99,83 @@ public final class ClusterClientConfigManager {
      * @param config new config to apply
      */
     public static void applyNewConfig(ClusterClientConfig config) {
-        currentProperty.updateValue(config);
+        clientConfigProperty.updateValue(config);
     }
 
-    private static class ClientConfigPropertyListener implements PropertyListener<ClusterClientConfig> {
+    public static void applyNewAssignConfig(ClusterClientAssignConfig clusterClientAssignConfig) {
+        clientAssignProperty.updateValue(clusterClientAssignConfig);
+    }
 
+    private static class ClientAssignPropertyListener implements PropertyListener<ClusterClientAssignConfig> {
         @Override
-        public void configUpdate(ClusterClientConfig config) {
+        public void configLoad(ClusterClientAssignConfig config) {
+            if (config == null) {
+                RecordLog.warn("[ClusterClientConfigManager] Empty initial client assignment config");
+                return;
+            }
             applyConfig(config);
         }
 
+        @Override
+        public void configUpdate(ClusterClientAssignConfig config) {
+            applyConfig(config);
+        }
+
+        private synchronized void applyConfig(ClusterClientAssignConfig config) {
+            if (!isValidAssignConfig(config)) {
+                RecordLog.warn(
+                    "[ClusterClientConfigManager] Invalid cluster client assign config, ignoring: " + config);
+                return;
+            }
+            if (serverPort == config.getServerPort() && config.getServerHost().equals(serverHost)) {
+                return;
+            }
+
+            RecordLog.info("[ClusterClientConfigManager] Assign to new target token server: " + config);
+
+            updateServerAssignment(config);
+        }
+    }
+
+    private static class ClientConfigPropertyListener implements PropertyListener<ClusterClientConfig> {
+
         @Override
         public void configLoad(ClusterClientConfig config) {
             if (config == null) {
-                RecordLog.warn("[ClusterClientConfigManager] Empty initial config");
+                RecordLog.warn("[ClusterClientConfigManager] Empty initial client config");
                 return;
             }
             applyConfig(config);
         }
 
+        @Override
+        public void configUpdate(ClusterClientConfig config) {
+            applyConfig(config);
+        }
+
         private synchronized void applyConfig(ClusterClientConfig config) {
-            if (!isValidConfig(config)) {
+            if (!isValidClientConfig(config)) {
                 RecordLog.warn(
                     "[ClusterClientConfigManager] Invalid cluster client config, ignoring: " + config);
                 return;
             }
-            RecordLog.info("[ClusterClientConfigManager] Updating new config: " + config);
-            if (config.getRequestTimeout() != requestTimeout) {
-                requestTimeout = config.getRequestTimeout();
-            }
-            updateServer(config);
+
+            RecordLog.info("[ClusterClientConfigManager] Updating to new client config: " + config);
+
+            updateClientConfigChange(config);
         }
     }
 
-    public static boolean isValidConfig(ClusterClientConfig config) {
-        return config != null && StringUtil.isNotBlank(config.getServerHost())
-            && config.getServerPort() > 0
-            && config.getServerPort() <= 65535
-            && config.getRequestTimeout() > 0;
+    private static void updateClientConfigChange(ClusterClientConfig config) {
+        if (config.getRequestTimeout() != requestTimeout) {
+            requestTimeout = config.getRequestTimeout();
+        }
     }
 
-    public static void updateServer(ClusterClientConfig config) {
+    private static void updateServerAssignment(/*@Valid*/ ClusterClientAssignConfig config) {
         String host = config.getServerHost();
         int port = config.getServerPort();
-        AssertUtil.assertNotBlank(host, "token server host cannot be empty");
-        AssertUtil.isTrue(port > 0, "token server port should be valid (positive)");
-        if (serverPort == port && host.equals(serverHost)) {
-            return;
-        }
+
         for (ServerChangeObserver observer : SERVER_CHANGE_OBSERVERS) {
             observer.onRemoteServerChange(config);
         }
@@ -124,6 +184,16 @@ public final class ClusterClientConfigManager {
         serverPort = port;
     }
 
+    public static boolean isValidAssignConfig(ClusterClientAssignConfig config) {
+        return config != null && StringUtil.isNotBlank(config.getServerHost())
+            && config.getServerPort() > 0
+            && config.getServerPort() <= 65535;
+    }
+
+    public static boolean isValidClientConfig(ClusterClientConfig config) {
+        return config != null && config.getRequestTimeout() > 0;
+    }
+
     public static String getServerHost() {
         return serverHost;
     }
@@ -136,5 +206,9 @@ public final class ClusterClientConfigManager {
         return requestTimeout;
     }
 
+    public static int getConnectTimeout() {
+        return connectTimeout;
+    }
+
     private ClusterClientConfigManager() {}
 }

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/config/ServerChangeObserver.java

@@ -24,7 +24,7 @@ public interface ServerChangeObserver {
     /**
      * Callback on remote server address change.
      *
-     * @param clusterClientConfig new cluster client config
+     * @param assignConfig new cluster assignment config
      */
-    void onRemoteServerChange(ClusterClientConfig clusterClientConfig);
+    void onRemoteServerChange(ClusterClientAssignConfig assignConfig);
 }

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/command/entity/ClusterClientStateEntity.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 1999-2018 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.csp.sentinel.command.entity;
+
+import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientAssignConfig;
+import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfig;
+
+/**
+ * @author Eric Zhao
+ * @since 1.4.1
+ */
+public class ClusterClientStateEntity {
+
+    private String serverHost;
+    private Integer serverPort;
+
+    private Integer clientState;
+
+    private Integer requestTimeout;
+
+    public String getServerHost() {
+        return serverHost;
+    }
+
+    public ClusterClientStateEntity setServerHost(String serverHost) {
+        this.serverHost = serverHost;
+        return this;
+    }
+
+    public Integer getServerPort() {
+        return serverPort;
+    }
+
+    public ClusterClientStateEntity setServerPort(Integer serverPort) {
+        this.serverPort = serverPort;
+        return this;
+    }
+
+    public Integer getRequestTimeout() {
+        return requestTimeout;
+    }
+
+    public ClusterClientStateEntity setRequestTimeout(Integer requestTimeout) {
+        this.requestTimeout = requestTimeout;
+        return this;
+    }
+
+    public Integer getClientState() {
+        return clientState;
+    }
+
+    public ClusterClientStateEntity setClientState(Integer clientState) {
+        this.clientState = clientState;
+        return this;
+    }
+
+    public ClusterClientConfig toClientConfig() {
+        return new ClusterClientConfig().setRequestTimeout(requestTimeout);
+    }
+
+    public ClusterClientAssignConfig toAssignConfig() {
+        return new ClusterClientAssignConfig()
+            .setServerHost(serverHost)
+            .setServerPort(serverPort);
+    }
+
+    @Override
+    public String toString() {
+        return "ClusterClientStateEntity{" +
+            "serverHost='" + serverHost + '\'' +
+            ", serverPort=" + serverPort +
+            ", clientState=" + clientState +
+            ", requestTimeout=" + requestTimeout +
+            '}';
+    }
+}

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchClusterClientConfigHandler.java

@@ -15,12 +15,14 @@
  */
 package com.alibaba.csp.sentinel.command.handler;
 
-import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfig;
+import com.alibaba.csp.sentinel.cluster.client.ClientConstants;
+import com.alibaba.csp.sentinel.cluster.client.TokenClientProvider;
 import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfigManager;
 import com.alibaba.csp.sentinel.command.CommandHandler;
 import com.alibaba.csp.sentinel.command.CommandRequest;
 import com.alibaba.csp.sentinel.command.CommandResponse;
 import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
+import com.alibaba.csp.sentinel.command.entity.ClusterClientStateEntity;
 import com.alibaba.fastjson.JSON;
 
 /**
@@ -32,11 +34,16 @@ public class FetchClusterClientConfigHandler implements CommandHandler<String> {
 
     @Override
     public CommandResponse<String> handle(CommandRequest request) {
-        ClusterClientConfig config = new ClusterClientConfig()
+        ClusterClientStateEntity stateVO = new ClusterClientStateEntity()
             .setServerHost(ClusterClientConfigManager.getServerHost())
             .setServerPort(ClusterClientConfigManager.getServerPort())
             .setRequestTimeout(ClusterClientConfigManager.getRequestTimeout());
-        return CommandResponse.ofSuccess(JSON.toJSONString(config));
+        if (TokenClientProvider.isClientSpiAvailable()) {
+            stateVO.setClientState(TokenClientProvider.getClient().getState());
+        } else {
+            stateVO.setClientState(ClientConstants.CLIENT_STATUS_OFF);
+        }
+        return CommandResponse.ofSuccess(JSON.toJSONString(stateVO));
     }
 }
 

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/command/handler/ModifyClusterClientConfigHandler.java

@@ -19,10 +19,12 @@ import java.net.URLDecoder;
 
 import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfig;
 import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfigManager;
+import com.alibaba.csp.sentinel.command.CommandConstants;
 import com.alibaba.csp.sentinel.command.CommandHandler;
 import com.alibaba.csp.sentinel.command.CommandRequest;
 import com.alibaba.csp.sentinel.command.CommandResponse;
 import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
+import com.alibaba.csp.sentinel.command.entity.ClusterClientStateEntity;
 import com.alibaba.csp.sentinel.log.RecordLog;
 import com.alibaba.csp.sentinel.util.StringUtil;
 import com.alibaba.fastjson.JSON;
@@ -43,10 +45,12 @@ public class ModifyClusterClientConfigHandler implements CommandHandler<String>
         try {
             data = URLDecoder.decode(data, "utf-8");
             RecordLog.info("[ModifyClusterClientConfigHandler] Receiving cluster client config: " + data);
-            ClusterClientConfig clusterClientConfig = JSON.parseObject(data, ClusterClientConfig.class);
-            ClusterClientConfigManager.applyNewConfig(clusterClientConfig);
+            ClusterClientStateEntity entity = JSON.parseObject(data, ClusterClientStateEntity.class);
 
-            return CommandResponse.ofSuccess("success");
+            ClusterClientConfigManager.applyNewConfig(entity.toClientConfig());
+            ClusterClientConfigManager.applyNewAssignConfig(entity.toAssignConfig());
+
+            return CommandResponse.ofSuccess(CommandConstants.MSG_SUCCESS);
         } catch (Exception e) {
             RecordLog.warn("[ModifyClusterClientConfigHandler] Decode client cluster config error", e);
             return CommandResponse.ofFailure(e, "decode client cluster config error");

sentinel-cluster/sentinel-cluster-common-default/src/main/java/com/alibaba/csp/sentinel/cluster/ClusterConstants.java

@@ -37,8 +37,9 @@ public final class ClusterConstants {
     public static final int PARAM_TYPE_BOOLEAN = 6;
     public static final int PARAM_TYPE_STRING = 7;
 
-    public static final int DEFAULT_CLUSTER_SERVER_PORT = 8730;
+    public static final int DEFAULT_CLUSTER_SERVER_PORT = 18730;
     public static final int DEFAULT_REQUEST_TIMEOUT = 20;
+    public static final int DEFAULT_CONNECT_TIMEOUT_MILLIS = 10 * 1000;
 
     private ClusterConstants() {}
 }

sentinel-core/src/main/java/com/alibaba/csp/sentinel/cluster/client/ClusterTokenClient.java

@@ -46,4 +46,11 @@ public interface ClusterTokenClient extends TokenService {
      * @throws Exception some error occurs
      */
     void stop() throws Exception;
+
+    /**
+     * Get state of the cluster token client.
+     *
+     * @return state of the cluster token client
+     */
+    int getState();
 }