Hystrix based resilient connector

connectors/pom.xml

@@ -61,6 +61,7 @@
         <module>grizzly-connector</module>
         <module>jetty-connector</module>
         <module>netty-connector</module>
+        <module>resilient-connector</module>
     </modules>
 
     <dependencies>

connectors/resilient-connector/pom.xml

@@ -0,0 +1,56 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.glassfish.jersey.connectors</groupId>
+    <artifactId>project</artifactId>
+    <version>2.24-SNAPSHOT</version>
+  </parent>
+  <artifactId>jersey-resilient-connector</artifactId>
+
+  <description>Jersey Resilient Client Transport via Hystrix</description>
+
+  <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <hystrix.core.version>1.5.5</hystrix.core.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.netflix.hystrix</groupId>
+            <artifactId>hystrix-core</artifactId>
+            <version>${hystrix.core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.test-framework.providers</groupId>
+            <artifactId>jersey-test-framework-provider-bundle</artifactId>
+            <version>${project.version}</version>
+            <type>pom</type>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.connectors</groupId>
+            <artifactId>jersey-grizzly-connector</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>com.sun.istack</groupId>
+                <artifactId>maven-istack-commons-plugin</artifactId>
+                <inherited>true</inherited>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>build-helper-maven-plugin</artifactId>
+                <inherited>true</inherited>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+</project>

connectors/resilient-connector/src/main/java/org/glassfish/jersey/resilient/connector/DefaultHystrixCommandConfigProvider.java

@@ -0,0 +1,104 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright (c) 2010-2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common Development
+ * and Distribution License("CDDL") (collectively, the "License").  You
+ * may not use this file except in compliance with the License.  You can
+ * obtain a copy of the License at
+ * http://glassfish.java.net/public/CDDL+GPL_1_1.html
+ * or packager/legal/LICENSE.txt.  See the License for the specific
+ * language governing permissions and limitations under the License.
+ *
+ * When distributing the software, include this License Header Notice in each
+ * file and include the License file at packager/legal/LICENSE.txt.
+ *
+ * GPL Classpath Exception:
+ * Oracle designates this particular file as subject to the "Classpath"
+ * exception as provided by Oracle in the GPL Version 2 section of the License
+ * file that accompanied this code.
+ *
+ * Modifications:
+ * If applicable, add the following below the License Header, with the fields
+ * enclosed by brackets [] replaced by your own identifying information:
+ * "Portions Copyright [year] [name of copyright owner]"
+ *
+ * Contributor(s):
+ * If you wish your version of this file to be governed by only the CDDL or
+ * only the GPL Version 2, indicate your decision by adding "[Contributor]
+ * elects to include this software in this distribution under the [CDDL or GPL
+ * Version 2] license."  If you don't indicate a single choice of license, a
+ * recipient has the option to distribute your version of this file under
+ * either the CDDL, the GPL Version 2 or to extend the choice of license to
+ * its licensees as provided above.  However, if you add GPL Version 2 code
+ * and therefore, elected the GPL Version 2 license, then the option applies
+ * only if the new code is made subject to such option by the copyright
+ * holder.
+ */
+package org.glassfish.jersey.resilient.connector;
+
+import org.glassfish.jersey.client.ClientRequest;
+
+import com.netflix.hystrix.HystrixCommandGroupKey;
+import com.netflix.hystrix.HystrixCommandKey;
+import com.netflix.hystrix.HystrixCommandProperties;
+import com.netflix.hystrix.HystrixCommandProperties.ExecutionIsolationStrategy;
+import com.netflix.hystrix.HystrixCommandProperties.Setter;
+
+/**
+ * Basic implementation of {@link ResilientConnectorProvider.HystrixCommandConfigProvider} which provides
+ * configurations for {@link HystrixCommand} and {@link HystrixObservableCommand} with the following default configurations.
+ *
+ * <ul>
+ *  <li>Command name - {@code request.getUri().getPath()}</li>
+ *  <li>SEMAPHORE execution isolation strategy.</li>
+ *  <li>Disabled execution timeout.</li>
+ * </ul>
+ *
+ * @author Joel Chengottusseriyil
+ *
+ * @see com.netflix.hystrix.HystrixCommandProperties.ExecutionIsolationStrategy
+ */
+class DefaultHystrixCommandConfigProvider implements ResilientConnectorProvider.HystrixCommandConfigProvider {
+
+    private static final String HYSTRIX_OBSERVABLE_COMMAND_GROUP_KEY = "JerseyClientHystrixObservableCommand";
+    private static final String HYSTRIX_COMMAND_GROUP_KEY = "JerseyClientHystrixCommand";
+
+    @Override
+    public String commandName(ClientRequest requestContext) {
+        return requestContext.getUri().getPath();
+    }
+
+    @Override
+    public com.netflix.hystrix.HystrixCommand.Setter commandConfig(ClientRequest requestContext) {
+        return com.netflix.hystrix.HystrixCommand.Setter
+                .withGroupKey(HystrixCommandGroupKey.Factory.asKey(HYSTRIX_COMMAND_GROUP_KEY))
+                .andCommandKey(HystrixCommandKey.Factory.asKey(commandName(requestContext)))
+                .andCommandPropertiesDefaults(defaultCommandProperties());
+    }
+
+    @Override
+    public com.netflix.hystrix.HystrixObservableCommand.Setter observableCommandConfig(ClientRequest requestContext) {
+        return com.netflix.hystrix.HystrixObservableCommand.Setter
+                .withGroupKey(HystrixCommandGroupKey.Factory.asKey(HYSTRIX_OBSERVABLE_COMMAND_GROUP_KEY))
+                .andCommandKey(HystrixCommandKey.Factory.asKey(commandName(requestContext)))
+                .andCommandPropertiesDefaults(defaultCommandProperties());
+    }
+
+    /**
+     * Gets an instance of {@link HystrixCommandProperties.Setter} with the following default configurations,
+     * <ul>
+     * <li>SEMAPHORE execution isolation strategy.</li>
+     * <li>Disabled execution timeout.</li>
+     * </ul>
+     *
+     * @return An instance of Hystrix command properties.
+     */
+    private static Setter defaultCommandProperties() {
+        return HystrixCommandProperties.Setter()
+                .withExecutionIsolationStrategy(ExecutionIsolationStrategy.SEMAPHORE)
+                .withExecutionTimeoutEnabled(false);
+    }
+}