Merge pull request #586 from sivabalachandran/master

Hystrix Spring integration article 2

hystrix/pom.xml

@@ -6,9 +6,15 @@
     <groupId>com.baeldung</groupId>
     <artifactId>hystrix</artifactId>
     <version>1.0</version>
-
     <name>hystrix</name>
 
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>1.4.0.RELEASE</version>
+        <relativePath></relativePath>
+    </parent>
+
     <properties>
 
         <!-- General -->
@@ -32,12 +38,35 @@
 
     <dependencies>
 
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-aop</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>com.netflix.hystrix</groupId>
             <artifactId>hystrix-core</artifactId>
             <version>${hystrix-core.version}</version>
         </dependency>
 
+        <dependency>
+            <groupId>com.netflix.hystrix</groupId>
+            <artifactId>hystrix-metrics-event-stream</artifactId>
+            <version>1.3.16</version>
+        </dependency>
+
+        <!-- https://mvnrepository.com/artifact/com.netflix.hystrix/hystrix-dashboard -->
+        <!--<dependency>
+            <groupId>com.netflix.hystrix</groupId>
+            <artifactId>hystrix-dashboard</artifactId>
+            <version>1.4.3</version>
+        </dependency>-->
+
         <dependency>
             <groupId>com.netflix.rxjava</groupId>
             <artifactId>rxjava-core</artifactId>
@@ -62,6 +91,10 @@
 
     <build>
         <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>

hystrix/src/main/java/com/baeldung/hystrix/AppConfig.java

@@ -0,0 +1,20 @@
+package com.baeldung.hystrix;
+
+import com.netflix.hystrix.contrib.metrics.eventstream.HystrixMetricsStreamServlet;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class AppConfig {
+
+    public static void main(String[] args) {
+        SpringApplication.run(AppConfig.class, args);
+    }
+
+    @Bean
+    public ServletRegistrationBean adminServletRegistrationBean() {
+        return new ServletRegistrationBean(new HystrixMetricsStreamServlet(), "/hystrix.stream");
+    }
+}

hystrix/src/main/java/com/baeldung/hystrix/HystrixAspect.java

@@ -0,0 +1,81 @@
+package com.baeldung.hystrix;
+
+import com.netflix.hystrix.*;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import javax.annotation.PostConstruct;
+
+@Component
+@Aspect
+public class HystrixAspect {
+
+    private HystrixCommand.Setter config;
+    private HystrixCommandProperties.Setter commandProperties;
+    private HystrixThreadPoolProperties.Setter threadPoolProperties;
+
+    @Around("@annotation(com.baeldung.hystrix.HystrixCircuitBreaker)")
+    public Object circuitBreakerAround(final ProceedingJoinPoint aJoinPoint) {
+        return new RemoteServiceCommand(config, aJoinPoint).execute();
+    }
+
+    @PostConstruct
+    private void setup() {
+        this.config = HystrixCommand.Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey(groupKey));
+        this.config = config.andCommandKey(HystrixCommandKey.Factory.asKey(key));
+
+        this.commandProperties = HystrixCommandProperties.Setter();
+        this.commandProperties.withExecutionTimeoutInMilliseconds(executionTimeout);
+        this.commandProperties.withCircuitBreakerSleepWindowInMilliseconds(sleepWindow);
+
+        this.threadPoolProperties= HystrixThreadPoolProperties.Setter();
+        this.threadPoolProperties.withMaxQueueSize(maxThreadCount).withCoreSize(coreThreadCount).withMaxQueueSize(queueCount);
+
+        this.config.andCommandPropertiesDefaults(commandProperties);
+        this.config.andThreadPoolPropertiesDefaults(threadPoolProperties);
+    }
+
+    private static class RemoteServiceCommand extends HystrixCommand<String> {
+
+        private final ProceedingJoinPoint joinPoint;
+
+        RemoteServiceCommand(final Setter config, final ProceedingJoinPoint joinPoint) {
+            super(config);
+            this.joinPoint = joinPoint;
+        }
+
+        @Override
+        protected String run() throws Exception {
+            try {
+                return (String) joinPoint.proceed();
+            } catch (final Throwable th) {
+                throw new Exception(th);
+            }
+
+        }
+    }
+
+    @Value("${remoteservice.command.execution.timeout}")
+    private int executionTimeout;
+
+    @Value("${remoteservice.command.sleepwindow}")
+    private int sleepWindow;
+
+    @Value("${remoteservice.command.threadpool.maxsize}")
+    private int maxThreadCount;
+
+    @Value("${remoteservice.command.threadpool.coresize}")
+    private int coreThreadCount;
+
+    @Value("${remoteservice.command.task.queue.size}")
+    private int queueCount;
+
+    @Value("${remoteservice.command.group.key}")
+    private String groupKey;
+
+    @Value("${remoteservice.command.key}")
+    private String key;
+}

hystrix/src/main/java/com/baeldung/hystrix/HystrixCircuitBreaker.java

@@ -0,0 +1,11 @@
+package com.baeldung.hystrix;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface HystrixCircuitBreaker {
+}

hystrix/src/main/java/com/baeldung/hystrix/HystrixController.java

@@ -0,0 +1,17 @@
+package com.baeldung.hystrix;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HystrixController {
+
+    @Autowired
+    private SpringExistingClient client;
+
+    @RequestMapping("/")
+    public String index() throws InterruptedException{
+        return client.invokeRemoteService();
+    }
+}

hystrix/src/main/java/com/baeldung/hystrix/RemoteServiceSimulator.java

@@ -1,15 +0,0 @@
-package com.baeldung.hystrix;
-
-
-public class RemoteServiceSimulator {
-
-    public String checkSomething(final long timeout) throws InterruptedException {
-
-        System.out.print(String.format("Waiting %sms. ", timeout));
-
-        // to simulate a real world delay in processing.
-        Thread.sleep(timeout);
-
-        return "Done waiting.";
-    }
-}

hystrix/src/main/java/com/baeldung/hystrix/RemoteServiceTestSimulator.java

@@ -1,7 +1,7 @@
 package com.baeldung.hystrix;
 
 
-class RemoteServiceTestSimulator {
+public class RemoteServiceTestSimulator {
 
     private long wait;
 

hystrix/src/main/java/com/baeldung/hystrix/SpringExistingClient.java

@@ -0,0 +1,17 @@
+package com.baeldung.hystrix;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+@Component("springClient")
+public class SpringExistingClient {
+
+    @Value("${remoteservice.timeout}")
+    private int remoteServiceDelay;
+
+    @HystrixCircuitBreaker
+    public String invokeRemoteService() throws InterruptedException{
+        return new RemoteServiceTestSimulator(remoteServiceDelay).execute();
+    }
+
+}

hystrix/src/main/resources/application.properties

@@ -0,0 +1,8 @@
+remoteservice.command.group.key=RemoteServiceGroup
+remoteservice.command.key=RemoteServiceKey
+remoteservice.command.execution.timeout=10000
+remoteservice.command.threadpool.coresize=5
+remoteservice.command.threadpool.maxsize=10
+remoteservice.command.task.queue.size=5
+remoteservice.command.sleepwindow=5000
+remoteservice.timeout=5000

hystrix/src/test/java/com/baeldung/hystrix/HystrixTimeoutTest.java

@@ -9,13 +9,15 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.util.concurrent.ExecutionException;
+
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 
 public class HystrixTimeoutTest {
 
-    private static HystrixCommand.Setter config;
+    private HystrixCommand.Setter config;
-    private static HystrixCommandProperties.Setter commandProperties = HystrixCommandProperties.Setter();
+    private HystrixCommandProperties.Setter commandProperties ;
 
 
     @Rule
@@ -23,6 +25,7 @@ public class HystrixTimeoutTest {
 
     @Before
     public void setup() {
+        commandProperties = HystrixCommandProperties.Setter();
         config = HystrixCommand
           .Setter
           .withGroupKey(HystrixCommandGroupKey.Factory.asKey("RemoteServiceGroup1"));
@@ -34,29 +37,86 @@ public class HystrixTimeoutTest {
     }
 
     @Test
-    public void givenTimeoutEqualTo100_andDefaultSettings_thenReturnSuccess() throws InterruptedException {
+    public void givenServiceTimeoutEqualTo100_andDefaultSettings_thenReturnSuccess() throws InterruptedException {
         assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(100)).execute(), equalTo("Success"));
     }
 
     @Test
-    public void givenTimeoutEqualTo10000_andDefaultSettings_thenExpectHystrixRuntimeException() throws InterruptedException {
+    public void givenServiceTimeoutEqualTo10000_andDefaultSettings_thenExpectHRE() throws InterruptedException {
         exception.expect(HystrixRuntimeException.class);
         new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(10_000)).execute();
     }
 
     @Test
-    public void givenTimeoutEqualTo5000_andExecutionTimeoutEqualTo10000_thenReturnSuccess() throws InterruptedException {
+    public void givenServiceTimeoutEqualTo5000_andExecutionTimeoutEqualTo10000_thenReturnSuccess()
+            throws InterruptedException {
         commandProperties.withExecutionTimeoutInMilliseconds(10_000);
         config.andCommandPropertiesDefaults(commandProperties);
-        assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(5_000)).execute(), equalTo("Success"));
+        assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(500)).execute(),
+                equalTo("Success"));
     }
 
     @Test
-    public void givenTimeoutEqualTo15000_andExecutionTimeoutEqualTo10000_thenExpectHystrixRuntimeException() throws InterruptedException {
+    public void givenServiceTimeoutEqualTo15000_andExecutionTimeoutEqualTo5000_thenExpectHRE()
+            throws InterruptedException {
         exception.expect(HystrixRuntimeException.class);
-        commandProperties.withExecutionTimeoutInMilliseconds(10_000);
+        commandProperties.withExecutionTimeoutInMilliseconds(5_000);
         config.andCommandPropertiesDefaults(commandProperties);
         new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(15_000)).execute();
     }
 
+    @Test
+    public void givenServiceTimeoutEqual_andExecutionTimeout_andThreadPool_thenReturnSuccess()
+            throws InterruptedException {
+        commandProperties.withExecutionTimeoutInMilliseconds(10_000);
+        config.andCommandPropertiesDefaults(commandProperties);
+        config.andThreadPoolPropertiesDefaults(HystrixThreadPoolProperties.Setter()
+                .withMaxQueueSize(10)
+                .withCoreSize(3)
+                .withQueueSizeRejectionThreshold(10));
+        assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(500)).execute(),
+                equalTo("Success"));
+    }
+
+    @Test
+    public void givenCircuitBreakerSetup_thenReturnSuccess() throws InterruptedException {
+
+        commandProperties.withExecutionTimeoutInMilliseconds(1000);
+
+        commandProperties.withCircuitBreakerSleepWindowInMilliseconds(4000);
+        commandProperties.withExecutionIsolationStrategy(
+                HystrixCommandProperties.ExecutionIsolationStrategy.THREAD);
+        commandProperties.withCircuitBreakerEnabled(true);
+        commandProperties.withCircuitBreakerRequestVolumeThreshold(1);
+
+        config.andCommandPropertiesDefaults(commandProperties);
+
+        config.andThreadPoolPropertiesDefaults(HystrixThreadPoolProperties.Setter()
+                .withMaxQueueSize(1)
+                .withCoreSize(1)
+                .withQueueSizeRejectionThreshold(1));
+
+        assertThat(this.invokeRemoteService(10000), equalTo(null));
+        assertThat(this.invokeRemoteService(10000), equalTo(null));
+        Thread.sleep(5000);
+
+        assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(500)).execute(),
+                equalTo("Success"));
+        assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(500)).execute(),
+                equalTo("Success"));
+        assertThat(new RemoteServiceTestCommand(config, new RemoteServiceTestSimulator(500)).execute(),
+                equalTo("Success"));
+    }
+
+    public String invokeRemoteService(long timeout) throws InterruptedException{
+        String response = null;
+        try{
+            response = new RemoteServiceTestCommand(config,
+                    new RemoteServiceTestSimulator(timeout)).execute();
+        }catch(HystrixRuntimeException ex){
+            System.out.println("ex = " + ex);
+        }
+        return response;
+    }
+
 }