TbHttpClient for Rest API call node: implemented shared event loop for netty for…

… any rest api call node instance

@@ -78,7 +78,7 @@ public class TbHttpClient {
     private AsyncRestTemplate httpClient;
     private Deque<ListenableFuture<ResponseEntity<String>>> pendingFutures;
 
-    TbHttpClient(TbRestApiCallNodeConfiguration config) throws TbNodeException {
+    TbHttpClient(TbRestApiCallNodeConfiguration config, EventLoopGroup eventLoopGroupShared) throws TbNodeException {
         try {
             this.config = config;
             if (config.getMaxParallelRequestsCount() > 0) {
@@ -139,8 +139,7 @@ public class TbHttpClient {
                 }
                 httpClient = new AsyncRestTemplate();
             } else {
-                this.eventLoopGroup = new NioEventLoopGroup();
-                Netty4ClientHttpRequestFactory nettyFactory = new Netty4ClientHttpRequestFactory(this.eventLoopGroup);
+                Netty4ClientHttpRequestFactory nettyFactory = new Netty4ClientHttpRequestFactory(getSharedOrCreateEventLoopGroup(eventLoopGroupShared));
                 nettyFactory.setSslContext(config.getCredentials().initSslContext());
                 nettyFactory.setReadTimeout(config.getReadTimeoutMs());
                 httpClient = new AsyncRestTemplate(nettyFactory);
@@ -150,6 +149,13 @@ public class TbHttpClient {
         }
     }
 
+    EventLoopGroup getSharedOrCreateEventLoopGroup(EventLoopGroup eventLoopGroupShared) {
+        if (eventLoopGroupShared != null) {
+            return eventLoopGroupShared;
+        }
+        return this.eventLoopGroup = new NioEventLoopGroup();
+    }
+
     private void checkSystemProxyProperties() throws TbNodeException {
         boolean useHttpProxy = !StringUtils.isEmpty(System.getProperty("http.proxyHost")) && !StringUtils.isEmpty(System.getProperty("http.proxyPort"));
         boolean useHttpsProxy = !StringUtils.isEmpty(System.getProperty("https.proxyHost")) && !StringUtils.isEmpty(System.getProperty("https.proxyPort"));

@@ -51,7 +51,7 @@ public class TbRestApiCallNode implements TbNode {
     @Override
     public void init(TbContext ctx, TbNodeConfiguration configuration) throws TbNodeException {
         TbRestApiCallNodeConfiguration config = TbNodeUtils.convert(configuration, TbRestApiCallNodeConfiguration.class);
-        httpClient = new TbHttpClient(config);
+        httpClient = new TbHttpClient(config, ctx.getSharedEventLoop());
         useRedisQueueForMsgPersistence = config.isUseRedisQueueForMsgPersistence();
         if (useRedisQueueForMsgPersistence) {
             log.warn("[{}][{}] Usage of Redis Template is deprecated starting 2.5 and will have no affect", ctx.getTenantId(), ctx.getSelfId());

+/**
+ * Copyright © 2016-2021 The Thingsboard 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 org.thingsboard.rule.engine.rest;
+
+
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.is;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.BDDMockito.willCallRealMethod;
+import static org.mockito.Mockito.mock;
+
+public class TbHttpClientTest {
+
+    EventLoopGroup eventLoop;
+    TbHttpClient client;
+
+    @Before
+    public void setUp() throws Exception {
+        client = mock(TbHttpClient.class);
+        willCallRealMethod().given(client).getSharedOrCreateEventLoopGroup(any());
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        if (eventLoop != null) {
+            eventLoop.shutdownGracefully();
+        }
+    }
+
+    @Test
+    public void givenSharedEventLoop_whenGetEventLoop_ThenReturnShared() {
+        eventLoop = mock(EventLoopGroup.class);
+        assertThat(client.getSharedOrCreateEventLoopGroup(eventLoop), is(eventLoop));
+    }
+
+    @Test
+    public void givenNull_whenGetEventLoop_ThenReturnShared() {
+        eventLoop = client.getSharedOrCreateEventLoopGroup(null);
+        assertThat(eventLoop, instanceOf(NioEventLoopGroup.class));
+    }
+}
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