Polish cluster token server handler related logic

- Enlarge retry timeout to 2s by default
- Improve remote address representation

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

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/NettyTransportServer.java

@@ -53,7 +53,7 @@ public class NettyTransportServer implements ClusterTokenServer {
     private static final int DEFAULT_EVENT_LOOP_THREADS = Math.max(1,
         SystemPropertyUtil.getInt("io.netty.eventLoopThreads", Runtime.getRuntime().availableProcessors() * 2));
     private static final int MAX_RETRY_TIMES = 3;
-    private static final int RETRY_SLEEP_MS = 1000;
+    private static final int RETRY_SLEEP_MS = 2000;
 
     private final int port;
 
@@ -103,7 +103,7 @@ public class NettyTransportServer implements ClusterTokenServer {
             @Override
             public void operationComplete(ChannelFuture future) {
                 if (future.cause() != null) {
-                    RecordLog.info("[NettyTransportServer] Token server start failed (port=" + port + ")",
+                    RecordLog.info("[NettyTransportServer] Token server start failed (port=" + port + "), failedTimes: " + failedTimes.get(),
                         future.cause());
                     currentState.compareAndSet(SERVER_STATUS_STARTING, SERVER_STATUS_OFF);
                     int failCount = failedTimes.incrementAndGet();

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/config/ServerTransportConfig.java

@@ -15,20 +15,21 @@
  */
 package com.alibaba.csp.sentinel.cluster.server.config;
 
+import com.alibaba.csp.sentinel.cluster.ClusterConstants;
+
 /**
  * @author Eric Zhao
  * @since 1.4.0
  */
 public class ServerTransportConfig {
 
-    public static final int DEFAULT_PORT = 8730;
     public static final int DEFAULT_IDLE_SECONDS = 600;
 
     private int port;
     private int idleSeconds;
 
     public ServerTransportConfig() {
-        this(DEFAULT_PORT, DEFAULT_IDLE_SECONDS);
+        this(ClusterConstants.DEFAULT_CLUSTER_SERVER_PORT, DEFAULT_IDLE_SECONDS);
     }
 
     public ServerTransportConfig(int port, int idleSeconds) {

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/handler/TokenServerHandler.java

@@ -15,6 +15,8 @@
  */
 package com.alibaba.csp.sentinel.cluster.server.handler;
 
+import java.net.InetSocketAddress;
+
 import com.alibaba.csp.sentinel.cluster.ClusterConstants;
 import com.alibaba.csp.sentinel.cluster.request.ClusterRequest;
 import com.alibaba.csp.sentinel.cluster.response.ClusterResponse;
@@ -105,6 +107,10 @@ public class TokenServerHandler extends ChannelInboundHandlerAdapter {
     }
 
     private String getRemoteAddress(ChannelHandlerContext ctx) {
-        return ctx.channel().remoteAddress().toString();
+        if (ctx.channel().remoteAddress() == null) {
+            return null;
+        }
+        InetSocketAddress inetAddress = (InetSocketAddress) ctx.channel().remoteAddress();
+        return inetAddress.getAddress().getHostAddress() + ":" + inetAddress.getPort();
     }
 }