一、Resilience4j 实现断路器

创建SpringBoot 项目 resilience4j-circuitbreaker-demo

1.1 依赖

        <dependency>
            <groupId>io.github.resilience4j</groupId>
            <artifactId>resilience4j-spring-boot2</artifactId>
            <version>0.14.1</version>
        </dependency>

1.2 配置

resilience4j:
  circuitbreaker: #断路器
    backends:
      menu:  #menu 熔断器
        event-consumer-buffer-size: 10
        failure-rate-threshold: 50
        ring-buffer-size-in-closed-state: 5
        ring-buffer-size-in-half-open-state: 3
        wait-duration-in-open-state: 5000
      order: #order 熔断器
        event-consumer-buffer-size: 10
        failure-rate-threshold: 50
        ring-buffer-size-in-closed-state: 5
        ring-buffer-size-in-half-open-state: 3
        wait-duration-in-open-state: 5000

1.3 注册和处理熔断

@RestController
@RequestMapping("/customer")
@Slf4j
public class CustomerController {
    @Autowired
    private CoffeeService coffeeService;
    @Autowired
    private CoffeeOrderService coffeeOrderService;
    private CircuitBreaker circuitBreaker;
    /**
     * 代码方式
     * 注册 "menu" 断路器
     * 注册 "menu" 限流器
     */
    public CustomerController(CircuitBreakerRegistry circuitBreakerRegistry) {
        circuitBreaker = circuitBreakerRegistry.circuitBreaker("menu");
    }
    @GetMapping("/getCoffeeMenu")
    public List<String> getCoffeeMenu() {
        return Try.ofSupplier(
                CircuitBreaker.decorateSupplier(circuitBreaker,
                                () -> coffeeService.coffee()))
                .recover(CircuitBreakerOpenException.class, Collections.emptyList()) //熔断处理
                .get(); //返回结果
    }
    /**
     * @return
     * @io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker 注解方式断路器 order
     */
    @PostMapping("order")
    @io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker(name = "order")
    public Map<String, Object> createOrder() {
        Map<String, Object> stringObjectMap = new HashMap<>();
        stringObjectMap.put("name", "布卡");
        log.info("Order {}", stringObjectMap);
        return coffeeOrderService.coffeeOrder(stringObjectMap);
    }
}

1.4 测试

docker 启动 consul 服务注册中心
启动项目 consul-waiter-service
启动项目 resilience4j-circuitbreaker-demo ```shell
执行
curl -X GET http://localhost:8011/customer/getCoffeeMenu
返回
[“38029 “,”ESPRESSO COFFEES $12”,”HANDMADE COFFEES $15”,”SOOTHING HOT ALTERNATIVES $20”,”COLD ALTERNATIVES $8”]

关闭consul-waiter-service项目

快速执行多次

curl -X GET http://localhost:8011/customer/getCoffeeMenu

返回[],熔断生效

<a name="KGaAi"></a>
## 二、Resilience4j 实现限流
<a name="bulkhead"></a>
### 2.1 bulkhead 
复制项目resilience4j-circuitbreaker-demo  修改为 bulkhead-customer-service
<a name="09cd0eaf"></a>
#### 2.1.1 配置
```yaml
resilience4j:
  circuitbreaker: #断路器
    backends:
      menu:  #menu 熔断器
        event-consumer-buffer-size: 10
        failure-rate-threshold: 50
        ring-buffer-size-in-closed-state: 5
        ring-buffer-size-in-half-open-state: 3
        wait-duration-in-open-state: 5000
      order: #order 熔断器
        event-consumer-buffer-size: 10
        failure-rate-threshold: 50
        ring-buffer-size-in-closed-state: 5
        ring-buffer-size-in-half-open-state: 3
        wait-duration-in-open-state: 5000
  #限流控制
  bulkhead:
    backends:
      menu:
        max-concurrent-call: 5 #最多5个线程
        max-wait-time: 5  #最多等待5s
      order:
        max-concurrent-call: 1
        max-wait-time: 5

2.1.2 注册和限制

@RestController
@RequestMapping("/customer")
@Slf4j
public class CustomerController {
    @Autowired
    private CoffeeService coffeeService;
    @Autowired
    private CoffeeOrderService coffeeOrderService;
    private CircuitBreaker circuitBreaker;
    private Bulkhead bulkhead;
    /**
     * 代码方式
     * 注册 "menu" 断路器
     * 注册 "menu" 限流器
     */
    public CustomerController(CircuitBreakerRegistry circuitBreakerRegistry,
                              BulkheadRegistry bulkheadRegistry) {
        circuitBreaker = circuitBreakerRegistry.circuitBreaker("menu");
        bulkhead = bulkheadRegistry.bulkhead("menu");
    }
    @GetMapping("/getCoffeeMenu")
    public List<String> getCoffeeMenu() {
        return Try.ofSupplier(
                Bulkhead.decorateSupplier(bulkhead,
                        CircuitBreaker.decorateSupplier(circuitBreaker,
                                () -> coffeeService.coffee())))
                .recover(CircuitBreakerOpenException.class, Collections.emptyList()) //熔断处理
                .recover(BulkheadFullException.class, Collections.emptyList())   
                .get(); //返回结果
    }
    /**
     * @return
     * @io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker 注解方式断路器 order
     * @io.github.resilience4j.bulkhead.annotation.Bulkhead 注解方式限流 order
     */
    @PostMapping("order")
    @io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker(name = "order")
    @io.github.resilience4j.bulkhead.annotation.Bulkhead(name = "order")
    public Map<String, Object> createOrder() {
        Map<String, Object> stringObjectMap = new HashMap<>();
        stringObjectMap.put("name", "布卡");
        log.info("Order {}", stringObjectMap);
        return coffeeOrderService.coffeeOrder(stringObjectMap);
    }
}

2.1.3 测试

docker 启动 consul 服务注册中心
启动项目 consul-waiter-service
启动项目 bulkhead-customer-service
安装 ab 性能测试工具 ```shell sudo apt-get update sudo apt-get install apache2-utils

测试

-n 总的请求数 -c 一次同时并发的请求数 ab -n 10 -c 5 http://localhost:8011/customer/getCoffeeMenu


- 输出结果
![image.png](https://cdn.nlark.com/yuque/0/2020/png/438760/1596377597208-28351c26-bfdf-4091-b832-1cf6415639a4.png#align=left&display=inline&height=459&margin=%5Bobject%20Object%5D&name=image.png&originHeight=918&originWidth=1048&size=181003&status=done&style=none&width=524)
- 加大并发（结果有13个失败）
```shell
ab -n 20 -c 10 http://localhost:8011/customer/getCoffeeMenu

2.2 RateLimiter

创建项目 ratelimiter-waiter-service

2.2.1 配置

resilience4j:
  ratelimiter:
    limiters:
      coffee:
        limit-for-period: 5  #限制5次
        limit-refresh-period-in-millis: 30000  #30秒
        register-health-indicator: true
        subscribe-for-events: true
        timeout-in-millis: 5000 #5秒超时
      order:
        limit-for-period: 3
        limit-refresh-period-in-millis: 30000
        register-health-indicator: true
        subscribe-for-events: true
        timeout-in-millis: 1000

2.2.2 注册RateLimiter

@Slf4j
@RestController
public class WaiterController {
    private RateLimiter rateLimiter;
    public WaiterController(RateLimiterRegistry rateLimiterRegistry) {
        //非注解方式,注册限流器
        rateLimiter = rateLimiterRegistry.rateLimiter("coffee");
    }
    /**
     * @param request
     * @return
     */
    @GetMapping(value = "/coffee", produces = "application/json")
    public List<String> coffeeMenu(HttpServletRequest request) {
        List<String> result = null;
        try {
            result = rateLimiter.executeSupplier(() -> Arrays.asList(request.getServerPort() + " "
                    , "ESPRESSO COFFEES $12"
                    , "HANDMADE COFFEES $15"
                    , "SOOTHING HOT ALTERNATIVES $20"
                    , "COLD ALTERNATIVES $8")
            );
            log.info("Get Order: {}", result);
        } catch (RequestNotPermitted e) {
            log.warn("Request Not Permitted! {}", e.getMessage(), e);
        }
        return result;
    }
    /**
     * 注解方式限流
     *
     * @param params
     * @return
     */
    @io.github.resilience4j.ratelimiter.annotation.RateLimiter(name = "order")
    @PostMapping(value = "/order", consumes = "application/json")
    public Map<String, Object> coffeeMenu(@RequestBody Map<String, Object> params) {
        log.info("order coffee");
        params.put("status", "success");
        params.put("payMoney", "$19");
        return params;
    }
}

2.2.3 测试

本地docker 启动consul 服务注册中心
启动项目 bulkhead-customer-service
启动项目 ratelimiter-waiter-service

访问 http://localhost:8011/customer/getCoffeeMenu ，接口限制30秒内访问5次

项目地址

https://github.com/h-dj/SpringCloud-Learning

后端知识点学习笔记

SpringCloud之Resilience4j熔断

一、Resilience4j 实现断路器

1.1 依赖

1.2 配置

1.3 注册和处理熔断

1.4 测试

执行

返回

关闭consul-waiter-service项目

快速执行多次

返回[],熔断生效

2.1.2 注册和限制

2.1.3 测试

测试

2.2 RateLimiter

2.2.1 配置

2.2.2 注册RateLimiter

2.2.3 测试

项目地址

参考