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29 Dec 2017

springCloud微服务服务消费与均衡负载

2.服务消费者(Ribbon)

Ribbon是一个基于HTTP和TCP客户端的负载均衡器。
准备工作

启动服务注册中心：eureka-server：`java -jar simple.jar`
启动服务提供方：compute-service：`java -jar simple.jar >log2222.log`
再启动一个服务提供方:compute-service：`java -jar target/jun-1.0-SNAPSHOT.jar --server.port=2223 >log2223.log`

2.1 客户端负载均衡的消费者(Ribbbon)

构建基本Spring Boot项目

  1. pom.xml： 
    <parent>
    <artifactId>springCloud</artifactId>
    <groupId>com.jun</groupId>
    <version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>sys_ribbon</artifactId>
<packaging>jar</packaging>
<name>ribbon</name>
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-ribbon</artifactId>
    </dependency>
</dependencies>
  2. RibbonApplication 类 
    @SpringBootApplication
//@EnableEurekaClient
@EnableDiscoveryClient//添加发现服务能力
public class RibbonApplication {
 @Bean
 @LoadBalanced//开启均衡负载
 RestTemplate restTemplate() {
     return new RestTemplate();
 }
 public static void main(String[] args) {
     SpringApplication.run(RibbonApplication.class, args);
 }
}
  3. 创建Controller来消费COMPUTE-SERVICE的add服务 
    @RestController
public class Controller {
 @Autowired
 RestTemplate restTemplate;
 @RequestMapping(value = "/add", method = RequestMethod.GET)
 public String add() {
     return restTemplate.getForEntity("http://compute-service/add?a=10&b=20", String.class).getBody();
 }
 @RequestMapping(value = "/hi", method = RequestMethod.GET)
 public String hi() {
     return restTemplate.getForEntity("http://compute-service/hi?a=testRibbon", String.class).getBody();
 }
}
  4. application.properties中配置eureka服务注册中心 
    spring.application.name=ribbon-consumer
server.port=3333
# eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
eureka.client.serviceUrl.defaultZone=http://admin:123@localhost:1111/eureka/
eureka.instance.metadata-map.instanceId=${spring.application.name}:${server.port}
eureka.instance.lease-expiration-duration-in-seconds=1
eureka.instance.lease-renewal-interval-in-seconds=1
#eureka.client.fetchRegistry= true
#eureka.client.registry-fetch-interval-seconds=1
  5. 启动(mvn package&&java -jar target/jun-1.0-SNAPSHOT.jar)应用
    访问两次：http://localhost:3333/add http://localhost:3333/hi

2.2 断路器 Netflix Hystrix

调用故障或延迟，返回一个错误响应
Hystrix具备拥有回退机制和断路器功能的线程和信号隔离，请求缓存和请求打包，以及监控和配置等功能。

Ribbon中引入Hystrix

  1. 准备 启动eureka-server、compute-service、eureka-ribbon
    注册中心状态http://localhost:1111/
    访问http://localhost:3333/add
    关闭compute-service服务，访问http://localhost:3333/add

  2. pom.xml 
     <!-- 断路器 hystrix
      Feigh工程不需要引入Hystix-->
 <dependency>
     <groupId>org.springframework.cloud</groupId>
     <artifactId>spring-cloud-starter-hystrix</artifactId>
 </dependency>
  3. RibbonApplication主类 
    @SpringBootApplication
@EnableDiscoveryClient
@EnableCircuitBreaker//开启断路器
public class RibbonApplication {
 @Bean
 @LoadBalanced
 RestTemplate restTemplate() {
     return new RestTemplate();
 }
 public static void main(String[] args) {
     SpringApplication.run(RibbonApplication.class, args);
 }
}
  4. 改造原来的服务消费方式 
    @RestController
public class Controller {
 @Autowired
 RestTemplate restTemplate;
 @RequestMapping(value = "/add", method = RequestMethod.GET)
 @HystrixCommand(fallbackMethod = "addFallback")
 //指定调用失败断路器调用的函数
 public String add() {
     return restTemplate.getForEntity("http://compute-service/add?a=10&b=20", String.class).getBody();
 }
 public String addFallback() {
     return "error";
 }
}
  5. aplicarion.properties 
    hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds= 5000
hystrix.command.default.execution.timeout.enabled=false
  6. 验证断路器的回调
    依次启动eureka-server、compute-service、eureka-ribbon工程
    访问http://localhost:1111/可以看到注册中心的状态
    访问http://localhost:3333/add，页面显示：30
    关闭compute-service服务后再访问http://localhost:3333/add，页面显示：error

2.3 熔断监控Hystrix Dashboard

  1. 父项目pom.xml 
    <!-- Hystrix Dashboard (断路器：hystrix 仪表盘)
@EnableHystrixDashboard   http://localhost:3333/hystrix
-->
<!--http://localhost:1111/health -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
  2. RibbonApplication主类添加注解 
    @EnableHystrixDashboard
//断路器仪表盘  http://localhost:3333/hystrix
  3. 访问 1、 http://localhost:3333/hystrix.stream
    2、 http://localhost:1111/health
    3、 http://localhost:3333/hystrix 输入：http://localhost:3333/hystrix.stream 、2000 、title
    另一个窗口 http://localhost:3333/add

3. Feign声明式的Web Service客户端

可插拔的注解支持，包括Feign注解和JAX-RS注解、Spring MVC注解。Feign也支持可插拔的编码器和解码器。整合了Ribbon和Eureka来提供均衡负载的HTTP客户端实现。

3.1 web Service客户端

创建基础Spring Boot工程

  1. pom.xml： 
    <parent>
    <artifactId>springCloud</artifactId>
    <groupId>com.jun</groupId>
    <version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>sys_feign</artifactId>
<packaging>jar</packaging>
<name>feign</name>
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-feign</artifactId>
    </dependency>
</dependencies>
  2. FeignApplication.java 应用主类中： 
    @SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients//开启Feign功能
public class FeignApplication {
 public static void main(String[] args) {
     SpringApplication.run(FeignApplication.class, args);
 }
}
  3. 定义compute-service服务的接口： 
    //绑定该接口对应compute-service服务
@FeignClient("compute-service")//绑定该接口对应服务
public interface Client {
 @RequestMapping(method = RequestMethod.GET, value = "/add")
 Integer add(@RequestParam(value = "a") Integer a, @RequestParam(value = "b") Integer b);
}
  4. 在web层中调用上面定义的Client： 
    @RestController
public class Controller {
 @Autowired
 Client client;
 @RequestMapping(value = "/add", method = RequestMethod.GET)
 public Integer add() {
     return client.add(10, 20);
 }
}
  5. application.properties： 
    spring.application.name=feign
server.port=3344
#eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
eureka.client.serviceUrl.defaultZone=http://admin:123@localhost:1111/eureka/
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds= 5000
hystrix.command.default.execution.timeout.enabled=false
eureka.instance.metadata-map.instanceId=${spring.application.name}
eureka.instance.lease-expiration-duration-in-seconds=1
eureka.instance.lease-renewal-interval-in-seconds=1
#断路器 默认打开
#feign.hystrix.enabled=false
  6. 启动应用，访问几次：http://localhost:3344/add http://localhost:3344/hi

3.2 Feign使用Hystrix

  1. 准备 依次启动eureka-server、client-service、eureka-feign工程
    注册中心的状态：http://localhost:1111/
    访问http://localhost:3333/add
    关闭compute-service服务，访问http://localhost:3333/add

  2. 创建回调类 ClientHystrix 
    @Component
public class ClientHystrix implements Client {
 @Override
 public Integer add(@RequestParam(value = "a") Integer a, @RequestParam(value = "b") Integer b) {
     return -9999;
 }
 @Override
 public String hi(@RequestParam(value = "name") String name) {
     return "-9999";
 }
}
  3. 指定回调类 
    @FeignClient(value ="compute-service", fallback = ClientHystrix.class,configuration =="")
//绑定该接口对应compute-service服务
//@FeignClient("compute-service")//绑定该接口对应服务
//指定服务名，同时需要制定服务配置类
public interface Client {
 @RequestMapping(method = RequestMethod.GET, value = "/add")
//    @HystrixCommand(fallbackMethod="findByIdFallback")// 单个方法的fallback
 Integer add(@RequestParam(value = "a") Integer a, @RequestParam(value = "b") Integer b);
 @RequestMapping(method = RequestMethod.GET, value = "/hi")
 String hi(@RequestParam(value = "name") String name);
}
  4. 验证一下 访问 http://localhost:3344/hi http://localhost:3344/add 关闭client-service后再访问

3.3 熔断监控Hystrix Dashboard

  1. 主类 FeignApplication 添加注解 
    @EnableHystrixDashboard
@EnableCircuitBreaker
  2. 验证
  3. http://localhost:3344/hystrix.stream
  4. http://localhost:1111/health
  5. http://localhost:3344/hystrix 输入：http://localhost:3344/hystrix.stream 、2000 、title
    另一个窗口 http://localhost:3344/add

2.4 断路器聚合监控(Hystrix Turbine)

子模块 sys_turbine

  1. pom.xml 
    <modelVersion>4.0.0</modelVersion>
<artifactId>sys_turbine</artifactId>
<packaging>jar</packaging>
<name>turbine</name>
<dependencies>
    <!--断路器聚合监控-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-turbine</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-netflix-turbine</artifactId>
    </dependency>
</dependencies>
  2. TurbineApplication.java 
    @SpringBootApplication
@EnableTurbine
@EnableHystrixDashboard
public class TurbineApplication {
 public static void main(String[] args) {
     SpringApplication.run(TurbineApplication.class, args);
 }
}
  3. application.properties 
    spring.application.name=turbine
#服务注册中心的端口
server.port=3355
#是否从eureka服务器获取注册信息
eureka.client.fetch-registry=false
eureka.client.serviceUrl.defaultZone=http://admin:123@localhost:1111/eureka/
#是否开启自我保护模式，默认为true
eureka.server.enable-self-preservation=true
eureka.instance.appname=turbine
#eureka.instance.hostname=localhost
#eureka.instance.metadata-map.instanceId=${spring.application.name}:${spring.application.instance_id:${random.value}}
#eureka.instance.instance-id=
#eureka.instance.prefer-ip-address=true
eureka.instance.lease-expiration-duration-in-seconds=1
eureka.instance.lease-renewal-interval-in-seconds=1
eureka.client.fetchRegistry= true
eureka.client.registry-fetch-interval-seconds=1

3.1 application.properties 添加

# 集群名称，默认为default  多个用逗号分隔
# 访问 http://localhost:3355/turbine.stream?cluster={MAIN}
turbine.aggregator.clusterConfig=MAIN
# 监控哪些服务:配置Eureka中的serviceId列表
turbine.appConfig=feign,ribbon-consumer
turbine.clusterNameExpression=metadata['cluster']

feign,ribbon-consumer的application.properties 添加

eureka.instance.metadata-map.cluster=MAIN

访问

  1. http://localhost:3355/turbine.stream?cluster=MAIN
  2. http://localhost:1111/health
  3. http://localhost:3355/hystrix 输入：http://localhost:3355/turbine.stream?cluster=MAIN 、2000 、title
    另一个窗口 http://localhost:3344/add
    http://localhost:3333/add

3.1 application.properties 添加

# 集群名称，默认为default  多个用逗号分隔
# 访问 http://localhost:3355/turbine.stream
turbine.aggregator.clusterConfig=default
# 监控哪些服务:配置Eureka中的serviceId列表
turbine.appConfig=feign,ribbon-consumer
turbine.clusterNameExpression=new String("default")

访问

  1. http://localhost:3355/turbine.stream
  2. http://localhost:1111/health
  3. http://localhost:3355/hystrix 输入：http://localhost:3355/turbine.stream 、2000 、title
    另一个窗口 http://localhost:3344/add
    http://localhost:3333/add
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