一个简单的微服务系统：服务注册和发现，服务消费，负载均衡，断路器，智能路由，配置管理
服务注册中心：
eureka是一个高可用组件，没有后端缓存，每一个实例注册后向注册中心发送心跳，默认情况下，erureka server也是一个eureka clinet,必须指定server
引入依赖：
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka-server</artifactId> </dependency>
启用注册中心：
@EnableEurekaServer @SpringBootApplication public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } }
YML配置：
server:
port: 8761
spring:
application:
name: microservice-registry
profiles:
active: native
eureka:
instance:
prefer-ip-address: true
client:
registerWithEureka: false
fetchRegistry: false
#serverUrl:
# defaultZone: http://otherRegistry:port/eureka/
eureka客户端：
依赖：
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency>
启动：
@SpringBootApplication @EnableDiscoveryClient @RestController public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } @RequestMapping("/hi") public String home(@RequestParam String name) { return "hi "+name+",i am from port: " +port; } }
YML配置：
spring: application: name: microservice-producer profiles: active: native eureka: instance: prefer-ip-address: true client: serviceUrl: defaultZone: http://localhost:8761/eureka/
在微服务架构中，业务都会被拆分成一个独立的服务，服务与服务间基于http restful
springcloud有两种服务调用方式：ribbon+restTemplate和feign，ribbon是一个负载均衡客户端，可以很好控制http和tcp的一些行为，feign默认集成也ribbon
ribbon+restTemplate：
依赖：
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-ribbon</artifactId> </dependency>
启动：
@SpringBootApplication @EnableDiscoveryClient public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } @Bean @LoadBalanced RestTemplate restTemplate() { return new RestTemplate(); } }
调用：
@Service public class HelloService { @Autowired RestTemplate restTemplate; public String hiService(String name) { return restTemplate.getForObject("http://eureka-producer/hi?name="+name,String.class); } }
YML配置：
spring: application: name: microservice-ribbon-consumer profiles: active: native eureka: instance: prefer-ip-address: true client: serviceUrl: defaultZone: http://localhost:8761/eureka/
feign：
依赖：
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-feign</artifactId> </dependency>
启动：
@SpringBootApplication @EnableDiscoveryClient @EnableFeignClients public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } }
调用：
@RestController public class HiController { @Autowired SchedualServiceHi schedualServiceHi; @RequestMapping(value = "/hi",method = RequestMethod.GET) public String sayHi(@RequestParam String name){ return schedualServiceHi.sayHiFromClientOne(name); } } @FeignClient(value = "eureka-producer") public interface SchedualServiceHi { @RequestMapping(value = "/hi",method = RequestMethod.GET) String sayHiFromClientOne(@RequestParam(value = "name") String name); }
yml配置：
spring: application: name: microservice-feign-consumer profiles: active: native eureka: instance: prefer-ip-address: true client: serviceUrl: defaultZone: http://localhost:8761/eureka/
断路器：应付故障传播问题
ribbon+restTemplate：
依赖：
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-hystrix</artifactId> </dependency>
启动：
@SpringBootApplication @EnableDiscoveryClient @EnableHystrix public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } @Bean @LoadBalanced RestTemplate restTemplate() { return new RestTemplate(); } }
使用：
@Service public class HelloService { @Autowired RestTemplate restTemplate; @HystrixCommand(fallbackMethod = "hiError") public String hiService(String name) { return restTemplate.getForObject("http://eureka-producer/hi?name="+name,String.class); } public String hiError(String name) { return "hi,"+name+",sorry,error!"; } }
YML中不需要额外配置
feign：
依赖同上
启动：
@SpringBootApplication @EnableDiscoveryClient @EnableFeignClients @EnableCircuitBreaker public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } }
使用：
@FeignClient(value = "eureka-producer", fallback = SchedualServiceHiHystric.class) public interface SchedualServiceHi { @RequestMapping(value = "/hi",method = RequestMethod.GET) String sayHiFromClientOne(@RequestParam(value = "name") String name); } @Component public class SchedualServiceHiHystric implements SchedualServiceHi { @Override public String sayHiFromClientOne(String name) { return "sorry "+name; } }
yml配置：
额外添加：
feign:
hystrix:
enabled:true
路由网关：
依赖：
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-zuul</artifactId> </dependency>
启动：
@EnableZuulProxy @EnableDiscoveryClient @SpringBootApplication public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } }
yml配置：
spring: application: name: microservice-gateway profiles: active: native eureka: instance: prefer-ip-address: true client: serviceUrl: defaultZone: http://localhost:8761/eureka/ zuul: routes: microservice-producer: path: /produce/** serviceId: microservice-producer
配置管理：
服务器依赖：
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
客户端依赖：
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
服务器端启动：
@EnableDiscoveryClient @SpringBootApplication @EnableConfigServer public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } }
客户端启动不需要额外添加
服务器端yml配置：
server: port: 8000 spring: application: name: microservice-config cloud: config: server: native: search-locations: classpath:/repo profiles: active: native eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/
客户端yml配置：
spring: application: name: microservice-gateway cloud: config: uri: http://localhost:8000 fail-fast: true profiles: active: native eureka: instance: prefer-ip-address: true client: serviceUrl: defaultZone: http://localhost:8761/eureka/
监控管理：
依赖：
<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>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
</dependency>
启动：
@SpringBootApplication @EnableTurbine @EnableDiscoveryClient @EnableHystrixDashboard public class App { public static void main( String[] args ) { SpringApplication.run(App.class, args); } }
yml配置：
server: port: 8770 security.basic.enabled: false turbine: aggregator: clusterConfig: default # 指定聚合哪些集群，多个使用","分割，默认为default。可使用http://.../turbine.stream?cluster={clusterConfig之一}访问 appConfig: microservice-feign-consumer,microservice-ribbon-consumer ### 配置Eureka中的serviceId列表，表明监控哪些服务 clusterNameExpression: new String("default") # 1. clusterNameExpression指定集群名称，默认表达式appName；此时：turbine.aggregator.clusterConfig需要配置想要监控的应用名称 # 2. 当clusterNameExpression: default时，turbine.aggregator.clusterConfig可以不写，因为默认就是default # 3. 当clusterNameExpression: metadata['cluster']时，假设想要监控的应用配置了eureka.instance.metadata-map.cluster: ABC，则需要配置，同时turbine.aggregator.clusterConfig: ABC
消息总线：将分布式节点用轻量的消息代理连接起来，可用于广播配置文件的更改或者服务之间的通讯，也可用于监控
