keep opensergoclient alive

src/main/java/io/opensergo/ConfigKind.java

@@ -26,8 +26,7 @@ public enum ConfigKind {
     FAULT_TOLERANCE_RULE("fault-tolerance.opensergo.io/v1alpha1/FaultToleranceRule", "FaultToleranceRule"),
     RATE_LIMIT_STRATEGY("fault-tolerance.opensergo.io/v1alpha1/RateLimitStrategy", "RateLimitStrategy"),
     THROTTLING_STRATEGY("fault-tolerance.opensergo.io/v1alpha1/ThrottlingStrategy", "ThrottlingStrategy"),
-    CONCURRENCY_LIMIT_STRATEGY("fault-tolerance.opensergo.io/v1alpha1/ConcurrencyLimitStrategy",
-        "ConcurrencyLimitStrategy"),
+    CONCURRENCY_LIMIT_STRATEGY("fault-tolerance.opensergo.io/v1alpha1/ConcurrencyLimitStrategy", "ConcurrencyLimitStrategy"),
     CIRCUIT_BREAKER_STRATEGY("fault-tolerance.opensergo.io/v1alpha1/CircuitBreakerStrategy", "CircuitBreakerStrategy");
 
     private final String kindName;

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

@@ -30,6 +30,8 @@
 import io.opensergo.util.AssertUtils;
 import io.opensergo.util.IdentifierUtils;
 
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
@@ -46,6 +48,7 @@ public class OpenSergoClient implements AutoCloseable {
     private final SubscribeRegistry subscribeRegistry;
 
     private AtomicInteger reqId;
+    protected volatile OpenSergoClientStatus status;
 
     public OpenSergoClient(String host, int port) {
         this.channel = ManagedChannelBuilder.forAddress(host, port)
@@ -56,17 +59,67 @@ public OpenSergoClient(String host, int port) {
         this.configCache = new SubscribedConfigCache();
         this.subscribeRegistry = new SubscribeRegistry();
         this.reqId = new AtomicInteger(0);
+        status = OpenSergoClientStatus.INITIAL;
     }
 
     public void start() throws Exception {
+        OpenSergoLogger.info("OpensergoClient is starting...");
+
+        if (status == OpenSergoClientStatus.INITIAL) {
+            OpenSergoLogger.info("open keepavlive thread");
+            Thread keepAliveThread = new Thread(this::keepAlive);
+            keepAliveThread.setName("thread-opensergo-keepalive-" + keepAliveThread.getId());
+            keepAliveThread.setDaemon(true);
+            keepAliveThread.start();
+        }
+
+        status = OpenSergoClientStatus.STARTING;
+
         this.requestAndResponseWriter = transportGrpcStub.withWaitForReady()
-            .subscribeConfig(new OpenSergoSubscribeClientObserver(configCache, subscribeRegistry));
+            .subscribeConfig(new OpenSergoSubscribeClientObserver(this));
+
+        OpenSergoLogger.info("begin to subscribe config-data...");
+        this.subscribeRegistry.getSubscriberKeysAll().forEach(subscribeKey -> {
+            this.subscribeConfig(subscribeKey);
+        });
+
+        OpenSergoLogger.info("openSergoClient is started");
+        status = OpenSergoClientStatus.STARTED;
+    }
+
+    private void keepAlive() {
+        // TODO change to event-based design, instead of for-loop.
+        for (;;) {
+            if (status == OpenSergoClientStatus.SHUTDOWN) {
+                return;
+            }
+
+            try {
+                if (status == OpenSergoClientStatus.INTERRUPTED) {
+                    OpenSergoLogger.info("try to restart openSergoClient...");
+                    this.start();
+                }
+                Thread.sleep(TimeUnit.SECONDS.toMillis(10));
+            } catch (InterruptedException e) {
+                OpenSergoLogger.error(e.toString(), e);
+            } catch (Exception e) {
+                try {
+                    this.close();
+                } catch (Exception ex) {
+                    status = OpenSergoClientStatus.SHUTDOWN;
+                }
+                OpenSergoLogger.error("close OpenSergoClient because of " + e, e);
+            }
+        }
     }
 
     @Override
     public void close() throws Exception {
         requestAndResponseWriter.onCompleted();
 
+        // stop the keepAliveThread
+        status = OpenSergoClientStatus.SHUTDOWN;
+
         // gracefully drain the requests, then close the connection
         channel.shutdown();
     }
@@ -77,8 +130,8 @@ public boolean unsubscribeConfig(SubscribeKey subscribeKey) {
         AssertUtils.assertNotNull(subscribeKey.getKind(), "kind cannot be null");
 
         if (requestAndResponseWriter == null) {
-            // TODO: return status that indicates not ready
-            throw new IllegalStateException("gRPC stream is not ready");
+            OpenSergoLogger.error("Fatal error occurred on OpenSergo gRPC ClientObserver", new IllegalStateException("gRPC stream is not ready"));
+            status = OpenSergoClientStatus.INTERRUPTED;
         }
         SubscribeRequestTarget subTarget = SubscribeRequestTarget.newBuilder()
             .setNamespace(subscribeKey.getNamespace()).setApp(subscribeKey.getApp())
@@ -106,8 +159,8 @@ public boolean subscribeConfig(SubscribeKey subscribeKey, OpenSergoConfigSubscri
         AssertUtils.assertNotNull(subscribeKey.getKind(), "kind cannot be null");
 
         if (requestAndResponseWriter == null) {
-            // TODO: return status that indicates not ready
-            throw new IllegalStateException("gRPC stream is not ready");
+            OpenSergoLogger.error("Fatal error occurred on OpenSergo gRPC ClientObserver", new IllegalStateException("gRPC stream is not ready"));
+            status = OpenSergoClientStatus.INTERRUPTED;
         }
         SubscribeRequestTarget subTarget = SubscribeRequestTarget.newBuilder()
             .setNamespace(subscribeKey.getNamespace()).setApp(subscribeKey.getApp())
@@ -124,8 +177,7 @@ public boolean subscribeConfig(SubscribeKey subscribeKey, OpenSergoConfigSubscri
         // Register subscriber to local.
         if (subscriber != null) {
             subscribeRegistry.registerSubscriber(subscribeKey, subscriber);
-            OpenSergoLogger.info("OpenSergo config subscriber registered, subscribeKey={}, subscriber={}",
-                subscribeKey, subscriber);
+            OpenSergoLogger.info("OpenSergo config subscriber registered, subscribeKey={}, subscriber={}", subscribeKey, subscriber);
         }
 
         return true;
@@ -135,4 +187,8 @@ public SubscribedConfigCache getConfigCache() {
         return configCache;
     }
 
+    public SubscribeRegistry getSubscribeRegistry() {
+        return subscribeRegistry;
+    }
+
 }

src/main/java/io/opensergo/OpenSergoClientStatus.java

@@ -0,0 +1,30 @@
+/*
+ * 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
+ *
+ *      https://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;
+
+/**
+ * @author Jiangnan Jia
+ **/
+public enum OpenSergoClientStatus {
+
+    /* initial*/
+    INITIAL,
+    STARTING,
+    STARTED,
+    INTERRUPTED,
+    SHUTDOWN
+
+}

src/main/java/io/opensergo/OpenSergoSubscribeClientObserver.java

@@ -30,8 +30,6 @@
 import io.opensergo.proto.transport.v1.SubscribeResponse;
 import io.opensergo.subscribe.OpenSergoConfigSubscriber;
 import io.opensergo.subscribe.SubscribeKey;
-import io.opensergo.subscribe.SubscribeRegistry;
-import io.opensergo.subscribe.SubscribedConfigCache;
 import io.opensergo.util.StringUtils;
 
 /**
@@ -41,13 +39,10 @@ public class OpenSergoSubscribeClientObserver implements ClientResponseObserver<
 
     private ClientCallStreamObserver<SubscribeRequest> requestStream;
 
-    private final SubscribedConfigCache configCache;
-    private final SubscribeRegistry subscribeRegistry;
+    private OpenSergoClient openSergoClient;
 
-    public OpenSergoSubscribeClientObserver(SubscribedConfigCache configCache,
-                                            SubscribeRegistry subscribeRegistry) {
-        this.configCache = configCache;
-        this.subscribeRegistry = subscribeRegistry;
+    public OpenSergoSubscribeClientObserver(OpenSergoClient openSergoClient) {
+        this.openSergoClient = openSergoClient;
     }
 
     @Override
@@ -58,7 +53,7 @@ public void beforeStart(ClientCallStreamObserver<SubscribeRequest> requestStream
     private LocalDataNotifyResult notifyDataChange(SubscribeKey subscribeKey, DataWithVersion dataWithVersion)
         throws Exception {
         long receivedVersion = dataWithVersion.getVersion();
-        SubscribedData cachedData = configCache.getDataFor(subscribeKey);
+        SubscribedData cachedData = this.openSergoClient.getConfigCache().getDataFor(subscribeKey);
         if (cachedData != null && cachedData.getVersion() > receivedVersion) {
             // The upcoming data is out-dated, so we'll not resolve the push request.
             return new LocalDataNotifyResult().setCode(OpenSergoTransportConstants.CODE_ERROR_VERSION_OUTDATED);
@@ -67,9 +62,9 @@ private LocalDataNotifyResult notifyDataChange(SubscribeKey subscribeKey, DataWi
         // Decode actual data from the raw "Any" data.
         List<Object> dataList = decodeActualData(subscribeKey.getKind().getKindName(), dataWithVersion.getDataList());
         // Update to local config cache.
-        configCache.updateData(subscribeKey, dataList, receivedVersion);
+        this.openSergoClient.getConfigCache().updateData(subscribeKey, dataList, receivedVersion);
 
-        List<OpenSergoConfigSubscriber> subscribers = subscribeRegistry.getSubscribersOf(subscribeKey);
+        List<OpenSergoConfigSubscriber> subscribers = this.openSergoClient.getSubscribeRegistry().getSubscribersOf(subscribeKey);
         if (subscribers == null || subscribers.isEmpty()) {
             // no-subscriber is acceptable (just for cache-and-pull mode)
             return LocalDataNotifyResult.withSuccess(dataList);
@@ -178,6 +173,11 @@ private List<Object> decodeActualData(String kind, List<Any> rawList) throws Exc
 
     @Override
     public void onError(Throwable t) {
+        // TODO add handles for different io.grpc.Status of Throwable from ClientCallStreamObserver<SubscribeRequest>
+        io.grpc.Status.Code errorCode = io.grpc.Status.fromThrowable(t).getCode();
+        if(errorCode.equals(io.grpc.Status.UNAVAILABLE.getCode())) {
+            this.openSergoClient.status = OpenSergoClientStatus.INTERRUPTED;
+        }
         OpenSergoLogger.error("Fatal error occurred on OpenSergo gRPC ClientObserver", t);
     }
 

src/main/java/io/opensergo/subscribe/SubscribeRegistry.java

@@ -16,6 +16,7 @@
 package io.opensergo.subscribe;
 
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -33,9 +34,14 @@ public void registerSubscriber(SubscribeKey key, OpenSergoConfigSubscriber subsc
         AssertUtils.assertNotNull(key, "subscribeKey cannot be null");
         AssertUtils.assertNotNull(subscriber, "subscriber cannot be null");
         List<OpenSergoConfigSubscriber> list = subscriberMap.computeIfAbsent(key, v -> new CopyOnWriteArrayList<>());
+        // TODO distinct the same OpenSergoConfigSubscriber
         list.add(subscriber);
     }
 
+    public Set<SubscribeKey> getSubscriberKeysAll() {
+        return subscriberMap.keySet();
+    }
+
     public List<OpenSergoConfigSubscriber> getSubscribersOf(SubscribeKey key) {
         if (key == null) {
             return null;