Sentinel：5.Sentinel的高级使用（二）降级规则持久化

心已赠人 2023-01-13 06:07 193阅读 0赞

### 文章目录 ###

*  1.教程
 *   *  1.1 修改Sentinel Dashboard源码
     *  1.2 修改Nacos配置中心里的nacos-sample-provider.yml
     *  1.3 重启Sentinel Dashboard控制台和nacos-sample-provider服务，验证是否实现降级规则持久化
     *  1.4 注意事项
 *  2. 小练习
 *   *   *  本文示例源码：

延续上一篇： [Sentinel：4.Sentinel的高级使用（一）流控规则持久化][Sentinel_4.Sentinel]，在其基础上，本篇开始演示 `降级规则的持久化`。

# 1.教程 #

在[Nacos：1.Nacos的基本使用（一）服务注册与发现][Nacos_1.Nacos]中，已经创建好了module：nacos-sample-provider，我们继续以它为例来演示Sentinel的高级使用。

## 1.1 修改Sentinel Dashboard源码 ##

1.  在sentinel-dashboard/src/main/java/com/alibaba/csp/sentinel/dashboard/rule/nacos目录下，新增以下代码

DegradeRuleNacosProvider.java

package com.alibaba.csp.sentinel.dashboard.rule.nacos;
    
    import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
    import com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;
    import com.alibaba.csp.sentinel.datasource.Converter;
    import com.alibaba.csp.sentinel.util.StringUtil;
    import com.alibaba.nacos.api.config.ConfigService;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /** * 从Nacos配置中心动态获取降级规则 */
    @Service
    public class DegradeRuleNacosProvider implements DynamicRuleProvider<List<DegradeRuleEntity>> { 
        private static Logger logger = LoggerFactory.getLogger(DegradeRuleNacosProvider.class);
    
        @Autowired
        private NacosPropertiesConfiguration nacosPropertiesConfiguration;
    
        @Autowired
        private ConfigService configService;
    
        @Autowired
        private Converter<String, List<DegradeRuleEntity>> converter;
    
        /** * 从Nacos配置中心拉取规则配置文件，并转换成正确的规则格式 * * @param appName 规则名/配置文件名 * @return * @throws Exception */
        @Override
        public List<DegradeRuleEntity> getRules(String appName) throws Exception { 
            String dataId = new StringBuffer(appName).append(NacosConstants.DEGRADE_DATA_ID_POSTFIX).toString();
            logger.info("Nacos Config DataId is:{}", dataId);
            String rules = configService.getConfig(dataId, nacosPropertiesConfiguration.getGroupId(), 3000);
            logger.info("pull DegradeRule from Nacos Config:{}", rules);
            if (StringUtil.isEmpty(rules)) { 
                return new ArrayList<>();
            }
            return converter.convert(rules);
        }
    }

DegradeRuleNacosPublisher.java

1.  修改NacosConfiguration.java和NacosConstants.java

NacosConfiguration.java

package com.alibaba.csp.sentinel.dashboard.rule.nacos;
    
    import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
    import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
    import com.alibaba.csp.sentinel.datasource.Converter;
    import com.alibaba.fastjson.JSON;
    import com.alibaba.nacos.api.PropertyKeyConst;
    import com.alibaba.nacos.api.config.ConfigFactory;
    import com.alibaba.nacos.api.config.ConfigService;
    import com.alibaba.nacos.api.exception.NacosException;
    import org.springframework.boot.context.properties.EnableConfigurationProperties;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import java.util.List;
    import java.util.Properties;
    
    /** * Nacos配置类 */
    @EnableConfigurationProperties(NacosPropertiesConfiguration.class)
    @Configuration
    public class NacosConfiguration { 
    
        /** * Converter转换器，将FlowRuleEntity转换成FlowRule * * @return */
        @Bean
        public Converter<List<FlowRuleEntity>, String> flowRuleEntityEncoder() { 
            return JSON::toJSONString;
        }
    
        /** * Converter反向转换器，将FlowRule转换成FlowRuleEntity * * @return */
        @Bean
        public Converter<String, List<FlowRuleEntity>> flowRuleEntityDecoder() { 
            return s -> JSON.parseArray(s, FlowRuleEntity.class);
        }
    
        /** * Converter转换器，将DegradeRuleEntity转换成DegradeRule * * @return */
        @Bean
        public Converter<List<DegradeRuleEntity>, String> degradeRuleEntityEncoder() { 
            return JSON::toJSONString;
        }
    
        /** * Converter反向转换器，将DegradeRule转换成DegradeRuleEntity * * @return */
        @Bean
        public Converter<String, List<DegradeRuleEntity>> degradeRuleEntityDecoder() { 
            return s -> JSON.parseArray(s, DegradeRuleEntity.class);
        }
    
        /** * Nacos配置服务 * * @param nacosPropertiesConfiguration * @return * @throws NacosException */
        @Bean
        public ConfigService nacosConfigService(NacosPropertiesConfiguration nacosPropertiesConfiguration) throws NacosException { 
            Properties properties = new Properties();
            properties.put(PropertyKeyConst.SERVER_ADDR, nacosPropertiesConfiguration.getServerAddr());
            properties.put(PropertyKeyConst.NAMESPACE, nacosPropertiesConfiguration.getNamespace());
            return ConfigFactory.createConfigService(properties);
        }
    }

NacosConstants.java

package com.alibaba.csp.sentinel.dashboard.rule.nacos;
    
    public class NacosConstants { 
    
        // 配置文件的后缀
        public static final String DATA_ID_POSTFIX = "-sentinel-flow";
        // 降级规则配置文件的后缀
        public static final String DEGRADE_DATA_ID_POSTFIX = "-sentinel-degrade";
        // 默认groupId
        public static final String GROUP_ID = "DEFAULT_GROUP";
    }

1.  在sentinel-dashboard/src/main/java/com/alibaba/csp/sentinel/dashboard/controller/v2目录下，新增以下代码

DegradeControllerV2.java

/* * Copyright 1999-2018 Alibaba Group Holding Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */
    package com.alibaba.csp.sentinel.dashboard.controller.v2;
    
    import com.alibaba.csp.sentinel.dashboard.auth.AuthAction;
    import com.alibaba.csp.sentinel.dashboard.auth.AuthService.PrivilegeType;
    import com.alibaba.csp.sentinel.dashboard.controller.DegradeController;
    import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
    import com.alibaba.csp.sentinel.dashboard.domain.Result;
    import com.alibaba.csp.sentinel.dashboard.repository.rule.RuleRepository;
    import com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;
    import com.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher;
    import com.alibaba.csp.sentinel.slots.block.RuleConstant;
    import com.alibaba.csp.sentinel.slots.block.degrade.circuitbreaker.CircuitBreakerStrategy;
    import com.alibaba.csp.sentinel.util.StringUtil;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.Date;
    import java.util.List;
    
    /** * Degrade rule controller (v2). * * @author wywangye * @since 1.4.0 */
    @RestController
    @RequestMapping(value = "/degrade")
    public class DegradeControllerV2 { 
    
        private final Logger logger = LoggerFactory.getLogger(DegradeController.class);
    
        @Autowired
        private RuleRepository<DegradeRuleEntity, Long> repository;
    
        @Autowired
    // @Qualifier("flowRuleDefaultProvider")
        @Qualifier("degradeRuleNacosProvider")     // 修改为Nacos的Provider
        private DynamicRuleProvider<List<DegradeRuleEntity>> ruleProvider;
        @Autowired
    // @Qualifier("flowRuleDefaultPublisher")
        @Qualifier("degradeRuleNacosPublisher")    // 修改为Nacos的Publisher
        private DynamicRulePublisher<List<DegradeRuleEntity>> rulePublisher;
    
        @GetMapping("/rules.json")
        @AuthAction(PrivilegeType.READ_RULE)
        public Result<List<DegradeRuleEntity>> apiQueryMachineRules(String app) { 
    
            if (StringUtil.isEmpty(app)) { 
                return Result.ofFail(-1, "app can't be null or empty");
            }
            try { 
                List<DegradeRuleEntity> rules = ruleProvider.getRules(app);
                if (rules != null && !rules.isEmpty()) { 
                    for (DegradeRuleEntity entity : rules) { 
                        entity.setApp(app);
                    }
                }
                rules = repository.saveAll(rules);
                return Result.ofSuccess(rules);
            } catch (Throwable throwable) { 
                logger.error("queryApps error:", throwable);
                return Result.ofThrowable(-1, throwable);
            }
        }
    
        @PostMapping("/rule")
        @AuthAction(PrivilegeType.WRITE_RULE)
        public Result<DegradeRuleEntity> apiAddRule(@RequestBody DegradeRuleEntity entity) { 
    
            Result<DegradeRuleEntity> checkResult = checkEntityInternal(entity);
            if (checkResult != null) { 
                return checkResult;
            }
            Date date = new Date();
            entity.setGmtCreate(date);
            entity.setGmtModified(date);
            try { 
                entity = repository.save(entity);
                publishRules(entity.getApp());
            } catch (Throwable t) { 
                logger.error("Failed to add new degrade rule, app={}, ip={}", entity.getApp(), entity.getIp(), t);
                return Result.ofThrowable(-1, t);
            }
            return Result.ofSuccess(entity);
        }
    
        @PutMapping("/rule/{id}")
        @AuthAction(PrivilegeType.WRITE_RULE)
        public Result<DegradeRuleEntity> apiUpdateRule(@PathVariable("id") Long id,
                                                       @RequestBody DegradeRuleEntity entity) { 
            if (id == null || id <= 0) { 
                return Result.ofFail(-1, "id can't be null or negative");
            }
            DegradeRuleEntity oldEntity = repository.findById(id);
            if (oldEntity == null) { 
                return Result.ofFail(-1, "Degrade rule does not exist, id=" + id);
            }
            entity.setApp(oldEntity.getApp());
            entity.setIp(oldEntity.getIp());
            entity.setPort(oldEntity.getPort());
            entity.setId(oldEntity.getId());
            Result<DegradeRuleEntity> checkResult = checkEntityInternal(entity);
            if (checkResult != null) { 
                return checkResult;
            }
    
            entity.setGmtCreate(oldEntity.getGmtCreate());
            entity.setGmtModified(new Date());
            try { 
                entity = repository.save(entity);
                publishRules(entity.getApp());
            } catch (Throwable t) { 
                logger.error("Failed to save degrade rule, id={}, rule={}", id, entity, t);
                return Result.ofThrowable(-1, t);
            }
            return Result.ofSuccess(entity);
        }
    
        @DeleteMapping("/rule/{id}")
        @AuthAction(PrivilegeType.DELETE_RULE)
        public Result<Long> delete(@PathVariable("id") Long id) { 
            if (id == null) { 
                return Result.ofFail(-1, "id can't be null");
            }
    
            DegradeRuleEntity oldEntity = repository.findById(id);
            if (oldEntity == null) { 
                return Result.ofSuccess(null);
            }
    
            try { 
                repository.delete(id);
                publishRules(oldEntity.getApp());
            } catch (Throwable throwable) { 
                logger.error("Failed to delete degrade rule, id={}", id, throwable);
                return Result.ofThrowable(-1, throwable);
            }
            return Result.ofSuccess(id);
        }
    
        private void publishRules(String app) throws Exception { 
            List<DegradeRuleEntity> rules = repository.findAllByApp(app);
            rulePublisher.publish(app, rules);
        }
    
        private <R> Result<R> checkEntityInternal(DegradeRuleEntity entity) { 
            if (entity == null) { 
                return Result.ofFail(-1, "invalid body");
            }
            if (StringUtil.isBlank(entity.getApp())) { 
                return Result.ofFail(-1, "app can't be blank");
            }
            if (StringUtil.isBlank(entity.getIp())) { 
                return Result.ofFail(-1, "ip can't be null or empty");
            }
            if (entity.getPort() == null || entity.getPort() <= 0) { 
                return Result.ofFail(-1, "invalid port: " + entity.getPort());
            }
            if (StringUtil.isBlank(entity.getLimitApp())) { 
                return Result.ofFail(-1, "limitApp can't be null or empty");
            }
            if (StringUtil.isBlank(entity.getResource())) { 
                return Result.ofFail(-1, "resource can't be null or empty");
            }
            Double threshold = entity.getCount();
            if (threshold == null || threshold < 0) { 
                return Result.ofFail(-1, "invalid threshold: " + threshold);
            }
            Integer recoveryTimeoutSec = entity.getTimeWindow();
            if (recoveryTimeoutSec == null || recoveryTimeoutSec <= 0) { 
                return Result.ofFail(-1, "recoveryTimeout should be positive");
            }
            Integer strategy = entity.getGrade();
            if (strategy == null) { 
                return Result.ofFail(-1, "circuit breaker strategy cannot be null");
            }
            if (strategy < CircuitBreakerStrategy.SLOW_REQUEST_RATIO.getType()
                    || strategy > RuleConstant.DEGRADE_GRADE_EXCEPTION_COUNT) { 
                return Result.ofFail(-1, "Invalid circuit breaker strategy: " + strategy);
            }
            if (entity.getMinRequestAmount()  == null || entity.getMinRequestAmount() <= 0) { 
                return Result.ofFail(-1, "Invalid minRequestAmount");
            }
            if (entity.getStatIntervalMs() == null || entity.getStatIntervalMs() <= 0) { 
                return Result.ofFail(-1, "Invalid statInterval");
            }
            if (strategy == RuleConstant.DEGRADE_GRADE_RT) { 
                Double slowRatio = entity.getSlowRatioThreshold();
                if (slowRatio == null) { 
                    return Result.ofFail(-1, "SlowRatioThreshold is required for slow request ratio strategy");
                } else if (slowRatio < 0 || slowRatio > 1) { 
                    return Result.ofFail(-1, "SlowRatioThreshold should be in range: [0.0, 1.0]");
                }
            } else if (strategy == RuleConstant.DEGRADE_GRADE_EXCEPTION_RATIO) { 
                if (threshold > 1) { 
                    return Result.ofFail(-1, "Ratio threshold should be in range: [0.0, 1.0]");
                }
            }
            return null;
        }
    }

1.  修改sentinel-dashboard/src/main/java/com/alibaba/csp/sentinel/dashboard/controller/DegradeController.java

DegradeRuleNacosPublisher.java

@RestController
    //@RequestMapping("/degrade")
    // 将URL更改为 "/old-degrade" 
    @RequestMapping("/old-degrade")
    public class DegradeController { 
        private final Logger logger = LoggerFactory.getLogger(DegradeController.class);
        ... ...
    }

1.  重新将sentinel-dashboard项目打包，然后启动服务

两种方式：

1.  官方文档教程：[README.md][]

【注意】

a. `官方教程中使用的端口是8080，用户可以自定义更改，本文中改成了8849。`

b. `官方教程中的mvan clean package指令，建议改成mvn clean package -Dmaven.test.skip=true，跳过test包的编译，以免编译失败`

1.  使用idea打开项目，等待所有maven依赖导入完成后，按下图设置，填入参数：`-Dserver.port=8849 -Dcsp.sentinel.dashboard.server=localhost:8849 -Dproject.name=sentinel-dashboard`，点击启动即可

## 1.2 修改Nacos配置中心里的nacos-sample-provider.yml ##

nacos-sample-provider.yml

# nacos配置中心信息参数
    nacos:
      instance:
        hostname: localhost
        port: 8848
    
    # sentinel信息参数
    sentinel:
      instance:
        hostname: localhost
        port: 8849
    
    spring:
      application:
        # 服务名，对应service-id
        name: nacos-sample-provider
      cloud:
        nacos:
          discovery:
            # 服务注册中心地址
            server-addr: ${ nacos.instance.hostname}:${ nacos.instance.port}
        sentinel:
          transport:
            # sentinel控制台地址
            dashboard: ${ sentinel.instance.hostname}:${ sentinel.instance.port}
          datasource:
            # 流控规则数据源
            flow:
              nacos:
                server-addr: ${ nacos.instance.hostname}:${ nacos.instance.port}
                data-id: ${ spring.application.name}-sentinel-flow
                group-id: DEFAULT_GROUP
                data-type: json
                # 格式要填写flow，对应流控规则
                rule-type: flow
            # 降级规则数据源
            degrade:
              nacos:
                server-addr: ${ nacos.instance.hostname}:${ nacos.instance.port}
                data-id: ${ spring.application.name}-sentinel-degrade
                group-id: DEFAULT_GROUP
                data-type: json
                # 格式要填写degrade，对应降级规则
                rule-type: degrade
    
    # 该服务启动后使用的端口
    server:
      port: 8001
      
    testValue: welcome!!!

## 1.3 重启Sentinel Dashboard控制台和nacos-sample-provider服务，验证是否实现降级规则持久化 ##

![image][]

![image][image 1]

## 1.4 注意事项 ##

1.  `如果创建规则后，在Nacos配置中心可以看到生成的规则配置文件，但是Sentinel Dashboard控制台看不到对应的规则，重启一下Nacos就好了`
2.  `在Sentinel Dashboard控制台“创建和修改规则”可以实时同步到Nacos，但是删除不会实时同步`
3.  `在Nacos配置中心“创建、修改和删除规则配置文件”都会实时同步到Sentinel`

# 2. 小练习 #

1.  读者可以按照上篇和本篇的教程，完成`授权规则`和`系统规则`的持久化；
2.  读者亲自尝试一下 “2.8 注意事项” 中的第3和第4点。

--------------------

### 本文示例源码： ###

[GitHub：WangYe8613/scanacos][GitHub_WangYe8613_scanacos]

\[commit id：1315a2d61dbdb7826eec2d88cec9713e6202a2d9\]

[Sentinel_4.Sentinel]: https://blog.csdn.net/w_y_x_y/article/details/115735785?spm=1001.2014.3001.5501
[Nacos_1.Nacos]: https://blog.csdn.net/w_y_x_y/article/details/115558041?spm=1001.2014.3001.5501
[README.md]: https://github.com/alibaba/Sentinel/tree/master/sentinel-dashboard
[image]: /images/20221022/d6614c50162e483989eb330eb23391ee.png
[image 1]: /images/20221022/aab0daa9225c4e34b1e38cf95506dd58.png
[GitHub_WangYe8613_scanacos]: https://github.com/WangYe8613/scanacos.git