SpringCloud集成Hystrix熔斷過程分步分解

更新時間：2022年09月28日 09:26:39 作者：Echoo2787

通過hystrix可以解決雪崩效應問題，它提供了資源隔離、降級機制、融斷、緩存等功能。接下來通過本文給大家分享SpringCloud集成Hystrix熔斷，感興趣的朋友一起看看吧

版本：

SpringBoot 2.6.1

SpringCloud 2021.0.0

依賴

<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
	<version>2.1.6.RELEASE</version>
</dependency>

貼@EnableHystrix注解

@EnableHystrix
@SpringBootApplication
public class ConsumerOneApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConsumerOneApplication.class, args);
    }
}

在需要熔斷的接口上貼@HystrixCommand注解

@RequestMapping("/consumerOne")
@RestController
public class ControllerOne {
    @Autowired
    private RestTemplate restTemplate;
    private String providerOneName = "provider-one";
    @HystrixCommand(fallbackMethod = "fallbackMethodOne")
    @RequestMapping("/serviceOne/{msg}")
    public String serviceOne(@PathVariable("msg") String msg) {
        return restTemplate.getForObject("http://" + providerOneName + "/providerOne/serviceOne/" + msg, String.class);
    }
	/** 熔斷回調方法 */
    private String fallbackMethodOne(String msg) {
        return "熔斷一默認返回:" + msg;
    }
}

異常熔斷測試

其中一個服務方拋異常，另一服務方正常返回

@RequestMapping("/providerOne")
@RestController
public class ControllerOne {
    @RequestMapping("/serviceOne/{msg}")
    public String serviceOne(@PathVariable("msg") String msg) {
        throw new RuntimeException();
        // return "8702:" + msg;
    }
}

@RequestMapping("/providerOne")
@RestController
public class ControllerOne {
    @RequestMapping("/serviceOne/{msg}")
    public String serviceOne(@PathVariable("msg") String msg) {
        return "8701:" + msg;
    }
}

訪問結果：

超時熔斷測試

全局

先配置默認超時時間為3秒（default為全局）

hystrix:
command:
default:
execution:
isolation:
thread:
timeoutInMilliseconds: 3000

在這里插入代碼片

其中一個接口睡眠4秒

@RequestMapping("/providerOne")
@RestController
public class ControllerOne {
    @RequestMapping("/serviceOne/{msg}")
    public String serviceOne(@PathVariable("msg") String msg) {
        try {
            Thread.sleep(4 * 1000);
            return "8702:" + msg;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return "8702:" + msg;
    }
}

訪問結果：

當服務方為延時返回的那個時，訪問等待了3秒返回熔斷默認對象

另一個正常

單個接口

除了全局外，另外給serviceTwo接口配置獨立的超時時間，其余不變

hystrix:
command:
default:
execution:
isolation:
thread:
timeoutInMilliseconds: 3000
serviceTwo:
execution:
isolation:
thread:
timeoutInMilliseconds: 5000

增加一個路徑為serviceTwo的接口

@RequestMapping("/consumerOne")
@RestController
public class ControllerOne {
    @Autowired
    private RestTemplate restTemplate;
    private String providerOneName = "provider-one";
    @HystrixCommand(fallbackMethod = "fallbackMethodOne")
    @RequestMapping("/serviceOne/{msg}")
    public String serviceOne(@PathVariable("msg") String msg) {
        return restTemplate.getForObject("http://" + providerOneName + "/providerOne/serviceOne/" + msg, String.class);
    }
    @HystrixCommand(fallbackMethod = "fallbackMethodOne")
    @RequestMapping("/serviceTwo/{msg}")
    public String serviceTwo(@PathVariable("msg") String msg) {
        return restTemplate.getForObject("http://" + providerOneName + "/providerOne/serviceOne/" + msg, String.class);
    }
    private String fallbackMethodOne(String msg) {
        return "熔斷一默認返回:" + msg;
    }
}

測試結果：