Update token client interface and default implementation

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

sentinel-cluster/sentinel-cluster-client-default/pom.xml

@@ -17,6 +17,11 @@
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-core</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-transport-common</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-cluster-common-default</artifactId>
@@ -26,5 +31,16 @@
             <groupId>io.netty</groupId>
             <artifactId>netty-all</artifactId>
         </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>

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

@@ -24,32 +24,92 @@ 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.ClusterClientConfigManager;
+import com.alibaba.csp.sentinel.cluster.client.config.ServerChangeObserver;
 import com.alibaba.csp.sentinel.cluster.log.ClusterStatLogUtil;
 import com.alibaba.csp.sentinel.cluster.request.ClusterRequest;
 import com.alibaba.csp.sentinel.cluster.request.data.FlowRequestData;
 import com.alibaba.csp.sentinel.cluster.request.data.ParamFlowRequestData;
 import com.alibaba.csp.sentinel.cluster.response.ClusterResponse;
 import com.alibaba.csp.sentinel.cluster.response.data.FlowTokenResponseData;
+import com.alibaba.csp.sentinel.log.RecordLog;
+import com.alibaba.csp.sentinel.util.StringUtil;
 
 /**
+ * Default implementation of {@link ClusterTokenClient}.
+ *
  * @author Eric Zhao
  * @since 1.4.0
  */
 public class DefaultClusterTokenClient implements ClusterTokenClient {
 
     private ClusterTransportClient transportClient;
+    private TokenServerDescriptor serverDescriptor;
 
     public DefaultClusterTokenClient() {
-        // TODO: load and create transport client here.
+        ClusterClientConfigManager.addServerChangeObserver(new ServerChangeObserver() {
+            @Override
+            public void onRemoteServerChange(ClusterClientConfig clusterClientConfig) {
+                changeServer(clusterClientConfig);
+            }
+        });
+        initNewConnection();
     }
 
     public DefaultClusterTokenClient(ClusterTransportClient transportClient) {
+        // TODO: only for test, remove this constructor.
         this.transportClient = transportClient;
     }
 
+    private boolean serverEqual(TokenServerDescriptor descriptor, ClusterClientConfig config) {
+        if (descriptor == null || config == null) {
+            return false;
+        }
+        return descriptor.getHost().equals(config.getServerHost()) && descriptor.getPort() == config.getServerPort();
+    }
+
+    private void initNewConnection() {
+        if (transportClient != null) {
+            return;
+        }
+        String host = ClusterClientConfigManager.getServerHost();
+        int port = ClusterClientConfigManager.getServerPort();
+        if (StringUtil.isBlank(host) || port <= 0) {
+            return;
+        }
+
+        try {
+            this.transportClient = new NettyTransportClient(host, port);
+            this.serverDescriptor = new TokenServerDescriptor(host, port);
+            transportClient.start();
+        } catch (Exception ex) {
+            ex.printStackTrace();
+        }
+    }
+
+    private void changeServer(/*@Valid*/ ClusterClientConfig config) {
+        if (serverEqual(serverDescriptor, config)) {
+            return;
+        }
+        try {
+            // TODO: what if the client is pending init?
+            if (transportClient != null && transportClient.isReady()) {
+                transportClient.stop();
+            }
+            // Replace with new, even if the new client is not ready.
+            this.transportClient = new NettyTransportClient(config);
+            this.serverDescriptor = new TokenServerDescriptor(config.getServerHost(), config.getServerPort());
+            transportClient.start();
+            RecordLog.info("[DefaultClusterTokenClient] New client created: " + serverDescriptor);
+        } catch (Exception ex) {
+            RecordLog.warn("[DefaultClusterTokenClient] Failed to change remote token server", ex);
+            ex.printStackTrace();
+        }
+    }
+
     @Override
     public TokenServerDescriptor currentServer() {
-        return new TokenServerDescriptor();
+        return serverDescriptor;
     }
 
     @Override
@@ -84,15 +144,11 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
         }
     }
 
-    private boolean notValidRequest(Long id, int count) {
-        return id == null || id <= 0 || count <= 0;
-    }
-
-    private TokenResult badRequest() {
-        return new TokenResult(TokenResultStatus.BAD_REQUEST);
-    }
-
     private TokenResult sendTokenRequest(ClusterRequest request) throws Exception {
+        if (transportClient == null) {
+            RecordLog.warn("[DefaultClusterTokenClient] Client not created, please check your config for cluster client");
+            return clientFail();
+        }
         ClusterResponse response = transportClient.sendRequest(request);
         TokenResult result = new TokenResult(response.getStatus());
         if (response.getData() != null) {
@@ -102,4 +158,16 @@ public class DefaultClusterTokenClient implements ClusterTokenClient {
         }
         return result;
     }
+
+    private boolean notValidRequest(Long id, int count) {
+        return id == null || id <= 0 || count <= 0;
+    }
+
+    private TokenResult badRequest() {
+        return new TokenResult(TokenResultStatus.BAD_REQUEST);
+    }
+
+    private TokenResult clientFail() {
+        return new TokenResult(TokenResultStatus.FAIL);
+    }
 }

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

@@ -23,6 +23,7 @@ import com.alibaba.csp.sentinel.cluster.ClusterTransportClient;
 import com.alibaba.csp.sentinel.cluster.client.codec.netty.NettyRequestEncoder;
 import com.alibaba.csp.sentinel.cluster.client.codec.netty.NettyResponseDecoder;
 import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfig;
+import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfigManager;
 import com.alibaba.csp.sentinel.cluster.client.handler.TokenClientHandler;
 import com.alibaba.csp.sentinel.cluster.client.handler.TokenClientPromiseHolder;
 import com.alibaba.csp.sentinel.cluster.exception.SentinelClusterException;
@@ -55,20 +56,25 @@ import io.netty.util.concurrent.GenericFutureListener;
  */
 public class NettyTransportClient implements ClusterTransportClient {
 
-    private ClusterClientConfig clientConfig;
-    private String host;
-    private int port;
+    private final String host;
+    private final int port;
 
     private Channel channel;
     private NioEventLoopGroup eventLoopGroup;
     private TokenClientHandler clientHandler;
 
     private AtomicInteger idGenerator = new AtomicInteger(0);
-
     private AtomicInteger failConnectedTime = new AtomicInteger(0);
 
-    public NettyTransportClient(ClusterClientConfig clientConfig, String host, int port) {
-        this.clientConfig = clientConfig;
+    public NettyTransportClient(ClusterClientConfig clientConfig) {
+        AssertUtil.notNull(clientConfig, "client config cannot be null");
+        this.host = clientConfig.getServerHost();
+        this.port = clientConfig.getServerPort();
+    }
+
+    public NettyTransportClient(String host, int port) {
+        AssertUtil.assertNotBlank(host, "remote host cannot be blank");
+        AssertUtil.isTrue(port > 0, "port should be positive");
         this.host = host;
         this.port = port;
     }
@@ -117,11 +123,13 @@ public class NettyTransportClient implements ClusterTransportClient {
         });
     }
 
-    public void start() {
+    @Override
+    public void start() throws Exception {
         connect(initClientBootstrap());
     }
 
-    public void stop() {
+    @Override
+    public void stop() throws Exception {
         if (channel != null) {
             channel.close();
             channel = null;
@@ -138,6 +146,7 @@ public class NettyTransportClient implements ClusterTransportClient {
         return request != null && request.getType() >= 0;
     }
 
+    @Override
     public boolean isReady() {
         return channel != null && clientHandler != null && clientHandler.hasStarted();
     }
@@ -159,8 +168,7 @@ public class NettyTransportClient implements ClusterTransportClient {
             ChannelPromise promise = channel.newPromise();
             TokenClientPromiseHolder.putPromise(xid, promise);
 
-            // TODO: timeout
-            if (!promise.await(20)) {
+            if (!promise.await(ClusterClientConfigManager.getRequestTimeout())) {
                 throw new SentinelClusterException(ClusterErrorMessages.REQUEST_TIME_OUT);
             }
 

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

@@ -37,8 +37,8 @@ public class DefaultRequestEntityWriter implements RequestEntityWriter<ClusterRe
 
         if (requestDataWriter == null) {
             // TODO: may need to throw exception?
-            RecordLog.warn(
-                "[NettyRequestEncoder] Cannot find matching request writer for type <{0}>, dropping the request", type);
+            RecordLog.warn("[DefaultRequestEntityWriter] Cannot find matching request writer for type <{0}>,"
+                + " dropping the request", type);
             return;
         }
         // Write head part of request.

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/codec/netty/NettyRequestEncoder.java

@@ -27,6 +27,7 @@ import io.netty.handler.codec.MessageToByteEncoder;
 
 /**
  * @author Eric Zhao
+ * @since 1.4.0
  */
 public class NettyRequestEncoder extends MessageToByteEncoder<ClusterRequest> {
 

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

@@ -62,4 +62,14 @@ public class ClusterClientConfig {
         this.connectTimeout = connectTimeout;
         return this;
     }
+
+    @Override
+    public String toString() {
+        return "ClusterClientConfig{" +
+            "serverHost='" + serverHost + '\'' +
+            ", serverPort=" + serverPort +
+            ", requestTimeout=" + requestTimeout +
+            ", connectTimeout=" + connectTimeout +
+            '}';
+    }
 }

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

@@ -15,16 +15,125 @@
  */
 package com.alibaba.csp.sentinel.cluster.client.config;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import com.alibaba.csp.sentinel.cluster.ClusterConstants;
+import com.alibaba.csp.sentinel.log.RecordLog;
+import com.alibaba.csp.sentinel.property.DynamicSentinelProperty;
+import com.alibaba.csp.sentinel.property.PropertyListener;
+import com.alibaba.csp.sentinel.property.SentinelProperty;
+import com.alibaba.csp.sentinel.util.AssertUtil;
+import com.alibaba.csp.sentinel.util.StringUtil;
 
 /**
  * @author Eric Zhao
+ * @since 1.4.0
  */
 public final class ClusterClientConfigManager {
 
-    private static volatile String serverIp;
+    /**
+     * Client config properties.
+     */
+    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 final PropertyListener<ClusterClientConfig> PROPERTY_LISTENER = new ClientConfigPropertyListener();
+    private static SentinelProperty<ClusterClientConfig> currentProperty = new DynamicSentinelProperty<>();
+
+    private static final List<ServerChangeObserver> SERVER_CHANGE_OBSERVERS = new ArrayList<>();
+
+    static {
+        currentProperty.addListener(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;
+        }
+    }
+
+    public static void addServerChangeObserver(ServerChangeObserver observer) {
+        AssertUtil.notNull(observer, "observer cannot be null");
+        SERVER_CHANGE_OBSERVERS.add(observer);
+    }
+
+    /**
+     * Apply new {@link ClusterClientConfig}, while the former config will be replaced.
+     *
+     * @param config new config to apply
+     */
+    public static void applyNewConfig(ClusterClientConfig config) {
+        currentProperty.updateValue(config);
+    }
+
+    private static class ClientConfigPropertyListener implements PropertyListener<ClusterClientConfig> {
+
+        @Override
+        public void configUpdate(ClusterClientConfig config) {
+            applyConfig(config);
+        }
+
+        @Override
+        public void configLoad(ClusterClientConfig config) {
+            if (config == null) {
+                RecordLog.warn("[ClusterClientConfigManager] Empty initial config");
+                return;
+            }
+            applyConfig(config);
+        }
+
+        private synchronized void applyConfig(ClusterClientConfig config) {
+            if (!isValidConfig(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);
+        }
+    }
+
+    public static boolean isValidConfig(ClusterClientConfig config) {
+        return config != null && StringUtil.isNotBlank(config.getServerHost())
+            && config.getServerPort() > 0
+            && config.getRequestTimeout() > 0;
+    }
+
+    public static void updateServer(ClusterClientConfig 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);
+        }
+
+        serverHost = host;
+        serverPort = port;
+    }
+
+    public static String getServerHost() {
+        return serverHost;
+    }
+
+    public static int getServerPort() {
+        return serverPort;
+    }
+
+    public static int getRequestTimeout() {
+        return requestTimeout;
+    }
+
     private ClusterClientConfigManager() {}
 }

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

@@ -0,0 +1,30 @@
+/*
+ * 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 1.4.0
+ */
+public interface ServerChangeObserver {
+
+    /**
+     * Callback on remote server address change.
+     *
+     * @param clusterClientConfig new cluster client config
+     */
+    void onRemoteServerChange(ClusterClientConfig clusterClientConfig);
+}

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

@@ -19,6 +19,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 import com.alibaba.csp.sentinel.cluster.client.ClientConstants;
 import com.alibaba.csp.sentinel.cluster.response.ClusterResponse;
+import com.alibaba.csp.sentinel.log.RecordLog;
 
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
@@ -34,6 +35,7 @@ public class TokenClientHandler extends ChannelInboundHandlerAdapter {
     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
         currentState.set(ClientConstants.CLIENT_STATUS_STARTED);
+        RecordLog.info("[TokenClientHandler] Client handler active, remote address: " + ctx.channel().remoteAddress());
     }
 
     @Override
@@ -48,13 +50,13 @@ public class TokenClientHandler extends ChannelInboundHandlerAdapter {
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-        super.exceptionCaught(ctx, cause);
-        cause.printStackTrace();
+        // TODO: should close the connection when an exception is raised.
+        RecordLog.warn("[TokenClientHandler] Client exception caught", cause);
     }
 
     @Override
     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
-        super.channelInactive(ctx);
+        RecordLog.info("[TokenClientHandler] Client handler inactive, remote address: " + ctx.channel().remoteAddress());
     }
 
     @Override

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

@@ -0,0 +1,42 @@
+/*
+ * 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.handler;
+
+import com.alibaba.csp.sentinel.cluster.client.config.ClusterClientConfig;
+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;
+
+/**
+ * @author Eric Zhao
+ * @since 1.4.0
+ */
+@CommandMapping(name = "modifyClusterConfig")
+public class ModifyClusterClientConfigHandler implements CommandHandler<String> {
+
+    @Override
+    public CommandResponse<String> handle(CommandRequest request) {
+
+        // TODO: parse the new config;
+        ClusterClientConfig clusterClientConfig = null;
+        ClusterClientConfigManager.applyNewConfig(clusterClientConfig);
+
+        return CommandResponse.ofSuccess("ok");
+    }
+}
+

sentinel-cluster/sentinel-cluster-client-default/src/main/resources/META-INF/services/com.alibaba.csp.sentinel.cluster.ClusterTokenClient

@@ -0,0 +1 @@
+com.alibaba.csp.sentinel.cluster.client.DefaultClusterTokenClient

sentinel-cluster/sentinel-cluster-client-default/src/main/resources/META-INF/services/com.alibaba.csp.sentinel.command.CommandHandler

@@ -0,0 +1 @@
+com.alibaba.csp.sentinel.command.handler.ModifyClusterClientConfigHandler

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

@@ -26,6 +26,20 @@ import com.alibaba.csp.sentinel.cluster.response.ClusterResponse;
  */
 public interface ClusterTransportClient {
 
+    /**
+     * Start the client.
+     *
+     * @throws Exception some error occurred (e.g. initialization failed)
+     */
+    void start() throws Exception;
+
+    /**
+     * Stop the client.
+     *
+     * @throws Exception some error occurred (e.g. shutdown failed)
+     */
+    void stop() throws Exception;
+
     /**
      * Send request to remote server and get response.
      *
@@ -34,4 +48,11 @@ public interface ClusterTransportClient {
      * @throws Exception some error occurs
      */
     ClusterResponse sendRequest(ClusterRequest request) throws Exception;
+
+    /**
+     * Check whether the client has been started and ready for sending requests.
+     *
+     * @return true if the client is ready to send requests, otherwise false
+     */
+    boolean isReady();
 }

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

@@ -26,7 +26,7 @@ public interface ClusterTokenClient extends TokenService {
     /**
      * Get descriptor of current token server.
      *
-     * @return current token server
+     * @return current token server if connected, otherwise null
      */
     TokenServerDescriptor currentServer();
 }

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

@@ -23,11 +23,10 @@ package com.alibaba.csp.sentinel.cluster;
  */
 public class TokenServerDescriptor {
 
-    private String host;
-    private int port;
-    private String type;
+    private final String host;
+    private final int port;
 
-    public TokenServerDescriptor() {}
+    private String type = "default";
 
     public TokenServerDescriptor(String host, int port) {
         this.host = host;
@@ -38,20 +37,10 @@ public class TokenServerDescriptor {
         return host;
     }
 
-    public TokenServerDescriptor setHost(String host) {
-        this.host = host;
-        return this;
-    }
-
     public int getPort() {
         return port;
     }
 
-    public TokenServerDescriptor setPort(int port) {
-        this.port = port;
-        return this;
-    }
-
     public String getType() {
         return type;
     }

sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/AssertUtil.java

@@ -28,6 +28,12 @@ public class AssertUtil {
         }
     }
 
+    public static void assertNotBlank(String string, String message) {
+        if (StringUtil.isBlank(string)) {
+            throw new IllegalArgumentException(message);
+        }
+    }
+
     public static void notNull(Object object, String message) {
         if (object == null) {
             throw new IllegalArgumentException(message);