SpringCloud高级(三) ——SpringCloud Alibaba Sentinel篇五

服务熔断功能

实现方式

  • 调用方的熔断保护
  • 调用方手动指定远程服务的降级策略。远程服务被降级处理,触发我们的熔断回调方法。注意:是给远程服务指定降级策略
  • 超大流量的时候,必须牺牲一些远程服务,在服务的提供方(远程服务)指定降级策略,提供方是在运行,但是不运行自己的业务逻辑,返回的是默认的降级数据(限流的数据)

sentinel整合ribbon+openFeign+fallback

Ribbon系列

启动nacos,sentinel。

准备工作

新建提供者模块:cloudalibaba-provider-payment9003
pom:

<dependencies>
        <!--SpringCloud ailibaba nacos -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.lzh.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- SpringBoot整合Web组件 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--日常通用jar包配置-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

配置文件:

server:
  port: 9003
spring:
  application:
    name: nacos-payment-provider
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848   #配置Nacos地址
#暴露监控端口
management:
  endpoints:
    web:
      exposure:
        include: '*'

启动类:

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain9003
{
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain9003.class, args);
    }
}

业务类:

@RestController
public class PaymentController
{
    @Value("${server.port}")
    private String serverPort;
    public static HashMap<Long, Payment> hashMap = new HashMap<>();
    static{
        hashMap.put(1L,new Payment(1L,"28a8c1e3bc2742d8848569891fb42181"));
        hashMap.put(2L,new Payment(2L,"bba8c1e3bc2742d8848569891ac32182"));
        hashMap.put(3L,new Payment(3L,"6ua8c1e3bc2742d8848569891xt92183"));
    }
    @GetMapping(value = "/paymentSQL/{id}")
    public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id){
        Payment payment = hashMap.get(id);
        CommonResult<Payment> result = new CommonResult(200,"from mysql,serverPort:  "+serverPort,payment);
        return result;
    }
}

测试:
http://localhost:9003/paymentSQL/1

在新建一个cloudalibaba-provider-payment9004,同上改改端口之类的就行。

新建一个消费者模块:cloudalibaba-consumer-nacos-order84
pom:

<dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <dependency>
            <groupId>com.lzh.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

配置文件:

server:
  port: 84
spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848  #nacos注册中心地址
    sentinel:
      transport:
        dashboard: localhost:8082  #sentinel地址
        port: 8719

启动类:

@EnableDiscoveryClient
@SpringBootApplication
@EnableFeignClients
public class OrderNacosMain84
{
    public static void main(String[] args) {
        SpringApplication.run(OrderNacosMain84.class, args);
    }
}

配置类:开启ribbon负载均衡

@Configuration
public class ApplicationContextConfig
{
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate()
    {
        return new RestTemplate();
    }
}

业务类:

@RestController
@Slf4j
public class CircleBreakerController {
    public static final String SERVICE_URL = "http://nacos-payment-provider";
    @Resource
    private RestTemplate restTemplate;

    @RequestMapping("/consumer/fallback/{id}")
    @SentinelResource(value = "fallback") //没有配置
    //@SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责业务异常
    //@SentinelResource(value = "fallback",blockHandler = "blockHandler") //blockHandler只负责sentinel控制台配置违规
//    @SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler",
//            exceptionsToIgnore = {IllegalArgumentException.class})
    public CommonResult<Payment> fallback(@PathVariable Long id) {
        CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id, CommonResult.class,id);

        if (id == 4) {
            throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");
        }else if (result.getData() == null) {
            throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");
        }

        return result;
    }
    //fallback
    public CommonResult handlerFallback(@PathVariable  Long id,Throwable e) {
        Payment payment = new Payment(id,"null");
        return new CommonResult<>(444,"兜底异常handlerFallback,exception内容  "+e.getMessage(),payment);
    }
    //blockHandler
    public CommonResult blockHandler(@PathVariable  Long id, BlockException blockException) {
        Payment payment = new Payment(id,"null");
        return new CommonResult<>(445,"blockHandler-sentinel限流,无此流水: blockException  "+blockException.getMessage(),payment);
    }
}

启动测试:
http://localhost:84/consumer/fallback/1 多次访问

{"code":200,"message":"from mysql,serverPort:  9004","data":{"id":1,"serial":"28a8c1e3bc2742d8848569891fb42181"}}
{"code":200,"message":"from mysql,serverPort:  9003","data":{"id":1,"serial":"28a8c1e3bc2742d8848569891fb42181"}}

出现负载均衡,环境准备完毕!

演示fallback

fallback管运行时异常;
blockHandler只负责sentinel控制台配置违规,限流时用到;

@SentinelResource没有任何配置
    @RequestMapping("/consumer/fallback/{id}")
    @SentinelResource(value = "fallback") //没有配置
    public CommonResult<Payment> fallback(@PathVariable Long id) {
        CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id, CommonResult.class,id);

        if (id == 4) {
            throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");
        }else if (result.getData() == null) {
            throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");
        }
        return result;
    }

访问:http://localhost:84/consumer/fallback/5
在这里插入图片描述
并没有限流,但是是接口自身出现的异常,给客户error页面,不友好。

只配置fallback
@RequestMapping("/consumer/fallback/{id}")
@SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责业务异常
public CommonResult<Payment> fallback(@PathVariable Long id) {
    CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id, CommonResult.class,id);

    if (id == 4) {
        throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");
    }else if (result.getData() == null) {
        throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");
    }

    return result;
}
//fallback
public CommonResult handlerFallback(@PathVariable  Long id,Throwable e) {
    Payment payment = new Payment(id,"null");
    return new CommonResult<>(444,"兜底异常handlerFallback,exception内容  "+e.getMessage(),payment);
}

在这里插入图片描述
当接口自身再次出现异常时,就可以使用fallback自定义的兜底异常处理方法了。会比较友好。

只配置blockHandler

不说了,之前一直都用这个。就是如果触发了限流的规则,就限流,并且返回blockHandler指定的兜底方法

fallback和blockHandler都配置
    @RequestMapping("/consumer/fallback/{id}")
    @SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler",
            exceptionsToIgnore = {IllegalArgumentException.class})
    public CommonResult<Payment> fallback(@PathVariable Long id) {
        CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id, CommonResult.class,id);
        if (id == 4) {
            throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");
        }else if (result.getData() == null) {
            throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");
        }
        return result;
    }
    //fallback
    public CommonResult handlerFallback(@PathVariable  Long id,Throwable e) {
        Payment payment = new Payment(id,"null");
        return new CommonResult<>(444,"兜底异常handlerFallback,exception内容  "+e.getMessage(),payment);
    }
    //blockHandler
    public CommonResult blockHandler(@PathVariable  Long id, BlockException blockException) {
        Payment payment = new Payment(id,"null");
        return new CommonResult<>(445,"blockHandler-sentinel限流,无此流水: blockException  "+blockException.getMessage(),payment);
    }

如果没有被限流,是接口自身的异常,兜底方法调的是blockHandler的;
如果被限流了,兜底方法调的是fallback 的;
如果既被限流了,又接口同时也出现异常,调哪个兜底方法?
调blockHandler的,因为blockHandler包在外头,限流了,都进不去接口里头,当然是调blockHandler的兜底方法啦。

忽略属性…
    @SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler",
            exceptionsToIgnore = {IllegalArgumentException.class})

意思就是如果接口发生IllegalArgumentException类型的异常,就不调用fallback 指定的兜底方法。
依旧使用系统的错误页面,给用户返回一个不太友好的界面。

Feign系列

A调用B,B容易炸,给A配,即调用方的熔断保护
之前豪猪哥,服务降级那学过,一样的
修改84模块
POM:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

配置文件:

#对Feign的支持
feign:
  sentinel:
    enabled: true

业务类:
带@FeignClient注解的业务接口

@FeignClient(value = "nacos-payment-provider",fallback = PaymentFallbackService.class)
public interface PaymentService
{
    @GetMapping(value = "/paymentSQL/{id}")
    CommonResult<Payment> paymentSQL(@PathVariable("id") Long id);
}

PaymentFallbackService实现类:

@Component
public class PaymentFallbackService implements PaymentService
{
    @Override
    public CommonResult<Payment> paymentSQL(Long id)
    {
        return new CommonResult<>(44444,"服务降级返回,---PaymentFallbackService",new Payment(id,"errorSerial"));
    }
}

Controller:

@Resource
private PaymentService paymentService;
@GetMapping(value = "/consumer/paymentSQL/{id}")
public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id) {
    return paymentService.paymentSQL(id);
}

主启动:

@EnableFeignClients

测试:启动9003提供者和当前84消费者
访问:http://localhost:84/consumer/paymentSQL/2

{"code":200,"message":"from mysql,serverPort:  9003","data":null}

此时故意关闭9003微服务提供者,看84消费者自动降级,不会被耗死:
再次访问接口:

{"code":44444,"message":"服务降级返回,---PaymentFallbackService","data":{"id":4,"serial":"errorSerial"}}

自定义流控响应

https://github.com/alibaba/Sentinel/tree/master/sentinel-adapter/sentinel-spring-webmvc-adapter
https://developer.aliyun.com/article/740637

除了使用,上面的fallbackblockHandler 之外,还有一种方式

@Configuration
public class SeckillWebConfig implements WebMvcConfigurer {
    @Autowired
    private SentinelWebInterceptor sentinelWebInterceptor;
    /**
     * 添加拦截器
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(sentinelWebInterceptor).addPathPatterns("/**");
    }
    /**
     * 自定义流控响应
     * @return
     */
    @Bean
    public SentinelWebInterceptor sentinelWebInterceptor(){
        SentinelWebMvcConfig sentinelWebMvcConfig = new SentinelWebMvcConfig();
        sentinelWebMvcConfig.setBlockExceptionHandler((request, response, e) -> {
            R error = R.error(BizCodeEnum.TOO_MANY_REQUEST.getCode(), BizCodeEnum.TOO_MANY_REQUEST.getMessage());
            response.setCharacterEncoding("utf-8");
            response.setContentType("application/json");
            response.getWriter().write(JSON.toJSONString(error));
        });
        return  new SentinelWebInterceptor(sentinelWebMvcConfig);
    }
}

配置文件:

spring.cloud.sentinel.filter.enabled=false

结果:限流时返回的流控响应,就是自己定义的了
在这里插入图片描述

注意:这个方式是在sentinel1.7.1才有的,之前的版本不是这样使用的
这样:配置文件不需要配置

@Configuration
public class GulimallSeckillSentinelConfig {
    public GulimallSeckillSentinelConfig() {
        WebCallbackManager.setUrlBlockHandler(new UrlBlockHandler() {
            @Override
            public void blocked(HttpServletRequest request, HttpServletResponse response, BlockException ex) throws IOException {
                R error = R.error(BizCodeEnum.TO_MANY_REQUEST.getCode(), BizCodeEnum.TO_MANY_REQUEST.getMessage());
                response.setCharacterEncoding("UTF-8");
                response.setContentType("application/json");
                response.getWriter().write(JSON.toJSONString(error));
            }
        });
    }
}

规则持久化

是什么?
一旦我们重启应用,Sentinel规则将消失,生产环境需要将配置规则进行持久化。
怎么玩?
将限流配置规则持久化进Nacos保存,只要刷新8401某个rest地址,sentinel控制台的流控规则就能看到,只要Nacos里面的配置不删除,针对8401Sentinel上的流控规则持续有效

演示:修改cloudalibaba-sentinel-service8401

pom:

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-datasource-nacos</artifactId>
</dependency>

配置文件:
在这里插入图片描述

        flow:  #名称随便
          nacos:
            server-addr: localhost:8848
            dataId:  cloudalibaba-sentinel-service
            groupId: DEFAULT_GROUP  #nacos的默认分组
            data-type: json  #json串是规则
            rule-type: flow #com.alibaba.cloud.sentinel.datasource.RuleType枚举类里有更多的规则类型
#            namespace:  nacos中存储规则的namespace
#        degrade:  #名称随便
#          nacos:
#            server-addr: localhost:8848
#            dataId:  ${spring.application.name}-degrade-rules
#            groupId: DEFAULT_GROUP  #nacos的默认分组
#            data-type: json  #json串是规则
#            rule-type: degrade	 #com.alibaba.cloud.sentinel.datasource.RuleType枚举类里有更多的规则类型

添加Nacos业务规则配置:添加一个配置,DataID,就是上面配置文件配的那个
在这里插入图片描述
给接口/testB添加一个规则

[
    {
         "resource": "/testB",
         "limitApp": "default",
         "grade":   1,
         "count":   2,
         "strategy": 0,
         "controlBehavior": 0,
         "clusterMode": false    
    }
]

在这里插入图片描述

启动8401。
访问接口:http://localhost:8401/testB
多次访问会发现,能够触发限流,然后到sentinel控制台看看:规则也已经同步上去了
在这里插入图片描述

问题1:修改nacos里的sentinel规则,能同步到sentinel里吗?

nacos里把QPS改为5
在这里插入图片描述
sentinel页面刷新,阈值为5了。
在这里插入图片描述
结论:在nacos上修改sentinel规则能实时推送到sentinel上。

问题2:修改sentinel里的规则,能同步到nacos里吗?

这里就不测了。不能

Sentinel控制台改造:规则同步到Nacos

1.下载源码:https://github.com/alibaba/Sentinel/releases/tag/1.7.2
在这里插入图片描述
2.导入源码
在这里插入图片描述
3.修改sentinel-dashboard模块
4.修改POM
sentinel-datasource-nacos<scope>注释了

        <!-- for Nacos rule publisher sample -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
<!--            <scope>test</scope>-->
        </dependency>

5.修改sidebar.html
找到sentinel-dashboard\src\main\webapp\resources\app\scripts\directives\sidebar中的sidebar.html

<li ui-sref-active="active">
    <a ui-sref="dashboard.flowV1({app: entry.app})">
        <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则
    </a>
</li>

修改为:其实就是把flowV1V1去掉

<li ui-sref-active="active">
    <a ui-sref="dashboard.flow({app: entry.app})">
        <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则
    </a>
</li>

6.在com.alibaba.csp.sentinel.dashboard.rule包下把nacos包复制到,com.alibaba.csp.sentinel.dashboard.rule目录下
在这里插入图片描述
7.只修改NacosConfig,其他不修改。

@Bean
public ConfigService nacosConfigService() throws Exception {
    Properties properties = new Properties();
    //nacos地址
    properties.put(PropertyKeyConst.SERVER_ADDR, "localhost:8848");
//        properties.put(PropertyKeyConst.NAMESPACE, "xxx");
    return ConfigFactory.createConfigService(properties);
}

8.NacosConfigUtil说明:
GROUP_ID 配置的规则在nacos中的分组
FLOW_DATA_ID_POSTFIX DataId的后缀

 public static final String GROUP_ID = "SENTINEL_GROUP";
 public static final String FLOW_DATA_ID_POSTFIX = "-flow-rules";

9.FlowRuleNacosProvider说明:拉取Nacos配置
其中有一段代码,意思是从nacos上获取配置,获取的方式:
DataIdappName + NacosConfigUtil.FLOW_DATA_ID_POSTFIX
组: NacosConfigUtil.GROUP_ID

        String rules = configService.getConfig(appName + NacosConfigUtil.FLOW_DATA_ID_POSTFIX,
            NacosConfigUtil.GROUP_ID, 3000);

10.FlowRuleNacosPublisher 说明:推送配置给Nacos
推送时,DataId还是应用名拼接NacosConfigUtil.FLOW_DATA_ID_POSTFIX
NacosConfigUtil.GROUP_ID

configService.publishConfig(app + NacosConfigUtil.FLOW_DATA_ID_POSTFIX,
   NacosConfigUtil.GROUP_ID, converter.convert(rules));

9.FlowControllerV2修改
将之前的ruleProvider,rulePublisher替换成下面的

    @Autowired
    @Qualifier("flowRuleNacosProvider")
    private DynamicRuleProvider<List<FlowRuleEntity>> ruleProvider;
    @Autowired
    @Qualifier("flowRuleNacosPublisher")
    private DynamicRulePublisher<List<FlowRuleEntity>> rulePublisher;

10.FlowControllerV1修改:
把方法publishRules注释了,替换成下面的

@Autowired
@Qualifier("flowRuleNacosPublisher")
private DynamicRulePublisher<List<FlowRuleEntity>> rulePublisher;

private CompletableFuture<Void>  publishRules(String app, String ip, Integer port) {
     List<FlowRuleEntity> rules = repository.findAllByMachine(MachineInfo.of(app, ip, port));
      try {
          rulePublisher.publish(app, rules);
          logger.info("添加限流规则成功{}", JSON.toJSONString(rules.stream().map(FlowRuleEntity::toRule).collect(Collectors.toList())));
          return sentinelApiClient.setFlowRuleOfMachineAsync(app, ip, port, rules);
  
      } catch (Exception e) {
          logger.info("添加限流规则失败{}",JSON.toJSONString(rules.stream().map(FlowRuleEntity::toRule).collect(Collectors.toList())));
          e.printStackTrace();
      }
      return null;
  }

11.打包编译,启动sentinel-dashboard
12.修改客户端8041
这里的DataId要和上面FlowRuleNacosProvider,FlowRuleNacosPublisher设置的一样,都是应用名拼接上-flow-rules
组也要一致。data-type: flow 表示流控规则
在这里插入图片描述
13.启动客户端
14.测试
添加一个流控规则。
在这里插入图片描述
nacos查看:配置同步过去了
在这里插入图片描述
访问接口试试:http://localhost:8401/testB
会出现限流。

sentinel里修改配置能实时同步到nacos, 同时nacos里改也能实时同步到sentinel
再加一个限流规则:
在这里插入图片描述nacos查看两条都在
在这里插入图片描述

这里只配置了流控规则同步到Nacos,其他规则也得配。

注意:我测试的时候,使用1.7.1的版本在新曾流控规则的时候,会出现非法类型的错误。
没解决这个问题,但是这一套配下来,在1.7.2版本下好使的。
排查了好久,还没找着什么原因。。。
在这里插入图片描述

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转载自blog.csdn.net/weixin_42412601/article/details/107312618