Merge pull request #10379 from Amitbhave/master

BAEL-3636 - introduction to alibaba sentinel

spring-cloud/pom.xml

@@ -44,6 +44,7 @@
         <module>spring-cloud-circuit-breaker</module>
         <module>spring-cloud-eureka-self-preservation</module>
         <!--<module>spring-cloud-openfeign</module>--> <!-- Fixing in JAVA-2820 -->
+        <module>spring-cloud-sentinel</module>
     </modules>
 
     <build>

spring-cloud/spring-cloud-sentinel/pom.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0"?>
+<project
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-cloud-sentinel</artifactId>
+    <name>spring-cloud-sentinel</name>
+    <url>http://maven.apache.org</url>
+    <packaging>pom</packaging>
+    <parent>
+        <groupId>com.baeldung.spring.cloud</groupId>
+        <artifactId>spring-cloud</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-core</artifactId>
+            <version>1.8.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-annotation-aspectj</artifactId>
+            <version>1.8.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-transport-simple-http</artifactId>
+            <version>1.8.0</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+</project>

spring-cloud/spring-cloud-sentinel/src/main/java/com/baeldung/spring/cloud/sentinel/SentinelApplication.java

@@ -0,0 +1,11 @@
+package com.baeldung.spring.cloud.sentinel;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SentinelApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(SentinelApplication.class, args);
+    }
+}

spring-cloud/spring-cloud-sentinel/src/main/java/com/baeldung/spring/cloud/sentinel/config/SentinelAspectConfiguration.java

@@ -0,0 +1,65 @@
+package com.baeldung.spring.cloud.sentinel.config;
+
+import com.alibaba.csp.sentinel.annotation.aspectj.SentinelResourceAspect;
+import com.alibaba.csp.sentinel.slots.block.RuleConstant;
+import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
+import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRuleManager;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
+import com.alibaba.csp.sentinel.slots.system.SystemRule;
+import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import javax.annotation.PostConstruct;
+import java.util.ArrayList;
+import java.util.List;
+
+@Configuration
+public class SentinelAspectConfiguration {
+
+    public static final String RESOURCE_NAME = "greeting";
+
+    @Bean
+    public SentinelResourceAspect sentinelResourceAspect() {
+        return new SentinelResourceAspect();
+    }
+
+    @PostConstruct
+    public void init() {
+        initFlowRules();
+        initDegradeRules();
+        initSystemProtectionRules();
+    }
+
+    private void initFlowRules() {
+        List<FlowRule> flowRules = new ArrayList<>();
+        FlowRule flowRule = new FlowRule();
+        // Defined resource
+        flowRule.setResource(RESOURCE_NAME);
+        flowRule.setGrade(RuleConstant.FLOW_GRADE_QPS);
+        // number of requests that QPS can pass in a second
+        flowRule.setCount(1);
+        flowRules.add(flowRule);
+        FlowRuleManager.loadRules(flowRules);
+    }
+
+    private void initDegradeRules() {
+        List<DegradeRule> rules = new ArrayList<DegradeRule>();
+        DegradeRule rule = new DegradeRule();
+        rule.setResource(RESOURCE_NAME);
+        rule.setCount(10);
+        rule.setTimeWindow(10);
+        rules.add(rule);
+        DegradeRuleManager.loadRules(rules);
+    }
+
+    private void initSystemProtectionRules() {
+        List<SystemRule> rules = new ArrayList<>();
+        SystemRule rule = new SystemRule();
+        rule.setHighestSystemLoad(10);
+        rules.add(rule);
+        SystemRuleManager.loadRules(rules);
+    }
+
+}

spring-cloud/spring-cloud-sentinel/src/main/java/com/baeldung/spring/cloud/sentinel/controller/GreetingController.java

@@ -0,0 +1,20 @@
+package com.baeldung.spring.cloud.sentinel.controller;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.spring.cloud.sentinel.service.GreetingService;
+
+@RestController
+public class GreetingController {
+
+    @Autowired
+    private GreetingService greetingService;
+
+    @GetMapping("/hello")
+    public String getGreeting() {
+        return greetingService.getGreeting();
+    }
+
+}

spring-cloud/spring-cloud-sentinel/src/main/java/com/baeldung/spring/cloud/sentinel/service/GreetingService.java

@@ -0,0 +1,19 @@
+package com.baeldung.spring.cloud.sentinel.service;
+
+import com.alibaba.csp.sentinel.annotation.SentinelResource;
+import org.springframework.stereotype.Service;
+
+@Service
+public class GreetingService {
+
+    @SentinelResource(value = "greeting", fallback = "getGreetingFallback")
+    public String getGreeting() {
+        return "Hello World!";
+    }
+
+    public String getGreetingFallback(Throwable e) {
+        e.printStackTrace();
+        return "Bye world!";
+    }
+
+}