Polish OpenSergoClient: add client ID && request ID management and improve logs

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

Author: sczyh30

src/main/java/io/opensergo/OpenSergoClient.java

@@ -18,6 +18,7 @@
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import io.grpc.stub.StreamObserver;
+import io.opensergo.log.OpenSergoLogger;
 import io.opensergo.proto.transport.v1.OpenSergoUniversalTransportServiceGrpc;
 import io.opensergo.proto.transport.v1.SubscribeOpType;
 import io.opensergo.proto.transport.v1.SubscribeRequest;
@@ -27,6 +28,9 @@
 import io.opensergo.subscribe.SubscribeRegistry;
 import io.opensergo.subscribe.SubscribedConfigCache;
 import io.opensergo.util.AssertUtils;
+import io.opensergo.util.IdentifierUtils;
+
+import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * @author Eric Zhao
@@ -41,6 +45,8 @@ public class OpenSergoClient implements AutoCloseable {
     private final SubscribedConfigCache configCache;
     private final SubscribeRegistry subscribeRegistry;
 
+    private AtomicInteger reqId;
+
     public OpenSergoClient(String host, int port) {
         this.channel = ManagedChannelBuilder.forAddress(host, port)
             // TODO: support TLS
@@ -49,6 +55,7 @@ public OpenSergoClient(String host, int port) {
         this.transportGrpcStub = OpenSergoUniversalTransportServiceGrpc.newStub(channel);
         this.configCache = new SubscribedConfigCache();
         this.subscribeRegistry = new SubscribeRegistry();
+        this.reqId = new AtomicInteger(0);
     }
 
     public void start() throws Exception {
@@ -71,7 +78,7 @@ public boolean unsubscribeConfig(SubscribeKey subscribeKey) {
 
         if (requestAndResponseWriter == null) {
             // TODO: return status that indicates not ready
-            return false;
+            throw new IllegalStateException("gRPC stream is not ready");
         }
         SubscribeRequestTarget subTarget = SubscribeRequestTarget.newBuilder()
             .setNamespace(subscribeKey.getNamespace()).setApp(subscribeKey.getApp())
@@ -100,21 +107,25 @@ public boolean subscribeConfig(SubscribeKey subscribeKey, OpenSergoConfigSubscri
 
         if (requestAndResponseWriter == null) {
             // TODO: return status that indicates not ready
-            return false;
+            throw new IllegalStateException("gRPC stream is not ready");
         }
         SubscribeRequestTarget subTarget = SubscribeRequestTarget.newBuilder()
             .setNamespace(subscribeKey.getNamespace()).setApp(subscribeKey.getApp())
             .addKinds(subscribeKey.getKind().getKindName())
             .build();
         SubscribeRequest request = SubscribeRequest.newBuilder()
+            .setRequestId(String.valueOf(reqId.incrementAndGet()))
             .setTarget(subTarget).setOpType(SubscribeOpType.SUBSCRIBE)
+            .setIdentifier(IdentifierUtils.generateIdentifier(System.identityHashCode(this)))
             .build();
         // Send SubscribeRequest
         requestAndResponseWriter.onNext(request);
 
         // Register subscriber to local.
         if (subscriber != null) {
             subscribeRegistry.registerSubscriber(subscribeKey, subscriber);
+            OpenSergoLogger.info("OpenSergo config subscriber registered, subscribeKey={}, subscriber={}",
+                subscribeKey, subscriber);
         }
 
         return true;

src/main/java/io/opensergo/util/IdentifierUtils.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2022, OpenSergo Authors
+ *
+ * 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 io.opensergo.util;
+
+import java.lang.management.ManagementFactory;
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.util.Enumeration;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import io.opensergo.log.OpenSergoLogger;
+
+/**
+ * @author xzd
+ */
+public class IdentifierUtils {
+
+    private static String ip;
+    private static String hostName;
+    private static int currentPid = -1;
+
+    private static final AtomicInteger counter = new AtomicInteger(0);
+
+    static {
+        try {
+            // Init the host information.
+            resolveHost();
+        } catch (Throwable e) {
+            OpenSergoLogger.error("Failed to resolve local host", e);
+        }
+    }
+
+    private static void resolveHost() throws Exception {
+        InetAddress addr = InetAddress.getLocalHost();
+        hostName = addr.getHostName();
+        ip = addr.getHostAddress();
+        if (addr.isLoopbackAddress()) {
+            // find the first IPv4 Address that not loopback
+            Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
+            while (interfaces.hasMoreElements()) {
+                NetworkInterface in = interfaces.nextElement();
+                Enumeration<InetAddress> addrs = in.getInetAddresses();
+                while (addrs.hasMoreElements()) {
+                    InetAddress address = addrs.nextElement();
+                    if (!address.isLoopbackAddress() && address instanceof Inet4Address) {
+                        ip = address.getHostAddress();
+                    }
+                }
+            }
+        }
+    }
+
+    public static int getPid() {
+        if (currentPid < 0) {
+            resolvePid();
+        }
+        return currentPid;
+    }
+
+    private static void resolvePid() {
+        // Note: this will trigger local host resolve, which might be slow.
+        String name = ManagementFactory.getRuntimeMXBean().getName();
+        currentPid = Integer.parseInt(name.split("@")[0]);
+    }
+
+    /**
+     * Generate a unique identifier of an OpenSergo client.
+     *
+     * @return a unique identifier
+     */
+    public static String generateIdentifier(long clientId) {
+        // format: hostname-ip-pid-clientHash
+        return String.format("%s-%s-%d-%d", hostName, ip, getPid(), clientId);
+    }
+
+}