Sentinel熔断降级流控生产级改造

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　　坚持原创，共同进步！前言
　　阿里开源Sentinel框架功能强大，实现了对服务的流控、熔断降级，并支持通过管理页面进行配置和监控。Client集成支持Java、Go等语言。但管理后台Dashboard，默认只适合开发和演示，要生产环境使用需要做相应源代码级改造。本文将介绍具体改造步骤，帮助大家更快实现在生产环境的部署应用。当然，如果预算充足，也可以直接使用阿里云开箱即用的Sentinel Dashboard服务。整体架构
　　Sentinel Dashboard规则默认存储在内存中，一旦服务重启，规则将丢失。要实现生产环境的大规模应用，需要把规则做持久化存储，Sentinel支持把nacos/zookeeper/apollo/redis等中间件作为存储介质。本文以Nacos作为规则存储端进行介绍。
　　整体架构如上图，Sentinel Dashboard通过界面操作，添加资源的规则，保存时将信息推送到nacos中。nacos收到数据变更，并实时推送到应用中的Sentinel SDK客户端，Sentinel SDK应用规则实现对服务资源的流控/熔断/降级管控。代码改造
　　Sentinel 使用nacos作为存储端，需要修改源代码。
　　1.源代码下载git clone git@github.com:hcq0514/Sentinel.git
　　IDE工具打开sentinel-dashboard项目模块
　　注意：将项目切换到使用的sentinel tag稳定版本，这里为1.8.6版本
　　2.pom.xml添加依赖
　　sentinel-dashboard模块pom.xml文件中，把sentinel-datasource-nacos依赖的注释掉。      com.alibaba.csp     sentinel-datasource-nacos      
　　3.前端页面修改
　　resources/app/scripts/directives/sidebar/sidebar.html文件，将dashboard.flowV1改成dashboard.flow
             流控规则 
　　4.Java代码修改
　　com.alibaba.csp.sentinel.dashboard.rule包中创建一个nacos包，用来存放Nacos相关代码类。
　　nacos包下创建NacosPropertiesConfiguration类，用于nacos server配置属性封装package com.alibaba.csp.sentinel.dashboard.rule.nacos;  import org.springframework.boot.context.properties.ConfigurationProperties;  @ConfigurationProperties(prefix = ＂sentinel.nacos＂) public class NacosPropertiesConfiguration {     private String namespace;     private String serverAddr;     private String username;     private String password;     //省略 属性 set/get 方法...... }
　　nacos包下创建NacosConfigUtil工具类public final class NacosConfigUtil {      public static final String GROUP_ID = ＂SENTINEL_GROUP＂;          public static final String FLOW_DATA_ID_POSTFIX = ＂-flow-rules＂;     public static final String DEGRADE_DATA_ID_POSTFIX = ＂-degrade-rules＂;     public static final String PARAM_FLOW_DATA_ID_POSTFIX = ＂-param-rules＂;     public static final String CLUSTER_MAP_DATA_ID_POSTFIX = ＂-cluster-map＂;      /**      * cc for `cluster-client`      */     public static final String CLIENT_CONFIG_DATA_ID_POSTFIX = ＂-cc-config＂;     /**      * cs for `cluster-server`      */     public static final String SERVER_TRANSPORT_CONFIG_DATA_ID_POSTFIX = ＂-cs-transport-config＂;     public static final String SERVER_FLOW_CONFIG_DATA_ID_POSTFIX = ＂-cs-flow-config＂;     public static final String SERVER_NAMESPACE_SET_DATA_ID_POSTFIX = ＂-cs-namespace-set＂;      private NacosConfigUtil() {} }
　　nacos包创建NacosConfiguration bean配置类@EnableConfigurationProperties(NacosPropertiesConfiguration.class) @Configuration public class NacosConfiguration {      @Bean     @Qualifier(＂degradeRuleEntityEncoder＂)     public Converter, String> degradeRuleEntityEncoder() {         return JSON::toJSONString;     }      @Bean     @Qualifier(＂degradeRuleEntityDecoder＂)     public Converter> degradeRuleEntityDecoder() {         return s -> JSON.parseArray(s, DegradeRuleEntity.class);     }      @Bean     @Qualifier(＂flowRuleEntityEncoder＂)     public Converter, String> flowRuleEntityEncoder() {         return JSON::toJSONString;     }      @Bean     @Qualifier(＂flowRuleEntityDecoder＂)     public Converter> flowRuleEntityDecoder() {         return s -> JSON.parseArray(s, FlowRuleEntity.class);     }      @Bean     public ConfigService nacosConfigService(NacosPropertiesConfiguration nacosPropertiesConfiguration) throws NacosException {         Properties properties = new Properties();         properties.put(PropertyKeyConst.SERVER_ADDR, nacosPropertiesConfiguration.getServerAddr());          if(StringUtils.isNotBlank(nacosPropertiesConfiguration.getNamespace())){             properties.put(PropertyKeyConst.NAMESPACE, nacosPropertiesConfiguration.getNamespace());         }          if(StringUtils.isNotBlank(nacosPropertiesConfiguration.getUsername())){             properties.put(PropertyKeyConst.USERNAME, nacosPropertiesConfiguration.getUsername());         }         if(StringUtils.isNotBlank(nacosPropertiesConfiguration.getPassword())){             properties.put(PropertyKeyConst.PASSWORD, nacosPropertiesConfiguration.getPassword());         }         return ConfigFactory.createConfigService(properties);     } }
　　nacos包下创建流控的provider和publisher实现类@Component(＂flowRuleNacosProvider＂) public class FlowRuleNacosProvider implements DynamicRuleProvider> {      @Autowired     private ConfigService configService;     @Autowired     @Qualifier(＂flowRuleEntityDecoder＂)     private Converter> converter;      @Override     public List getRules(String appName) throws Exception {         String rules = configService.getConfig(appName + NacosConfigUtil.FLOW_DATA_ID_POSTFIX,             NacosConfigUtil.GROUP_ID, 3000);         if (StringUtil.isEmpty(rules)) {             return new ArrayList<>();         }         return converter.convert(rules);     } }@Component(＂flowRuleNacosPublisher＂) public class FlowRuleNacosPublisher implements DynamicRulePublisher> {      @Autowired     private ConfigService configService;     @Autowired     @Qualifier(＂flowRuleEntityEncoder＂)     private Converter, String> converter;      @Override     public void publish(String app, List rules) throws Exception {         AssertUtil.notEmpty(app, ＂app name cannot be empty＂);         if (rules == null) {             return;         }         configService.publishConfig(app + NacosConfigUtil.FLOW_DATA_ID_POSTFIX,             NacosConfigUtil.GROUP_ID, converter.convert(rules));     } }
　　nacos包下创建熔断/降级的provider和publisher实现类@Component(＂degradeRuleNacosProvider＂) public class DegradeRuleNacosProvider implements DynamicRuleProvider> {      @Autowired     private ConfigService configService;     @Autowired     @Qualifier(＂degradeRuleEntityDecoder＂)     private Converter> converter;      @Override     public List getRules(String appName) throws Exception {         String rules = configService.getConfig(appName + NacosConfigUtil.DEGRADE_DATA_ID_POSTFIX,             NacosConfigUtil.GROUP_ID, 3000);         if (StringUtil.isEmpty(rules)) {             return new ArrayList<>();         }         return converter.convert(rules);     } }@Component(＂degradeRuleNacosPublisher＂) public class DegradeRuleNacosPublisher implements DynamicRulePublisher> {      @Autowired     private ConfigService configService;     @Autowired     @Qualifier(＂degradeRuleEntityEncoder＂)     private Converter, String> converter;      @Override     public void publish(String app, List rules) throws Exception {         AssertUtil.notEmpty(app, ＂app name cannot be empty＂);         if (rules == null) {             return;         }         configService.publishConfig(app + NacosConfigUtil.DEGRADE_DATA_ID_POSTFIX,             NacosConfigUtil.GROUP_ID, converter.convert(rules));     } }
　　修改com.alibaba.csp.sentinel.dashboard.controller.v2.FlowControllerV2类。将注入的bean标识由下图右边替换左边的值。将原有的服务引用基于内存存储，替换为nacos存储的服务引用。# 上面截图红框替换值 flowRuleDefaultProvider 替换为 flowRuleNacosProvider flowRuleDefaultPublisher 替换为 flowRuleNacosPublisher
　　删除com.alibaba.csp.sentinel.dashboard.controller.DegradeController类， com.alibaba.csp.sentinel.dashboard.controller.v2包下新增DegradeControllerV2类@RestController @RequestMapping(＂/degrade＂) public class DegradeControllerV2 {      private final Logger logger = LoggerFactory.getLogger(DegradeControllerV2.class);      @Autowired     private RuleRepository repository;      @Autowired     @Qualifier(＂degradeRuleNacosProvider＂)     private DynamicRuleProvider> ruleProvider;     @Autowired     @Qualifier(＂degradeRuleNacosPublisher＂)     private DynamicRulePublisher> rulePublisher;      @GetMapping(＂/rules.json＂)     @AuthAction(PrivilegeType.READ_RULE)     public Result> apiQueryMachineRules(String app, String ip, Integer port) {         if (StringUtil.isEmpty(app)) {             return Result.ofFail(-1, ＂app can＂t be null or empty＂);         }         if (StringUtil.isEmpty(ip)) {             return Result.ofFail(-1, ＂ip can＂t be null or empty＂);         }         if (port == null) {             return Result.ofFail(-1, ＂port can＂t be null＂);         }         try { //            List rules = sentinelApiClient.fetchDegradeRuleOfMachine(app, ip, port);             List 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 apiAddRule(@RequestBody DegradeRuleEntity entity) {         Result checkResult = checkEntityInternal(entity);         if (checkResult != null) {             return checkResult;         }         Date date = new Date();         entity.setGmtCreate(date);         entity.setGmtModified(date);         try {             entity = repository.save(entity);         } catch (Throwable t) {             logger.error(＂Failed to add new degrade rule, app={}, ip={}＂, entity.getApp(), entity.getIp(), t);             return Result.ofThrowable(-1, t);         }         if (!publishRules(entity.getApp(), entity.getIp(), entity.getPort())) {             logger.warn(＂Publish degrade rules failed, app={}＂, entity.getApp());         }         return Result.ofSuccess(entity);     }      @PutMapping(＂/rule/{id}＂)     @AuthAction(PrivilegeType.WRITE_RULE)     public Result 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 checkResult = checkEntityInternal(entity);         if (checkResult != null) {             return checkResult;         }          entity.setGmtCreate(oldEntity.getGmtCreate());         entity.setGmtModified(new Date());         try {             entity = repository.save(entity);         } catch (Throwable t) {             logger.error(＂Failed to save degrade rule, id={}, rule={}＂, id, entity, t);             return Result.ofThrowable(-1, t);         }         if (!publishRules(entity.getApp(), entity.getIp(), entity.getPort())) {             logger.warn(＂Publish degrade rules failed, app={}＂, entity.getApp());         }         return Result.ofSuccess(entity);     }      @DeleteMapping(＂/rule/{id}＂)     @AuthAction(PrivilegeType.DELETE_RULE)     public Result 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);         } catch (Throwable throwable) {             logger.error(＂Failed to delete degrade rule, id={}＂, id, throwable);             return Result.ofThrowable(-1, throwable);         }         if (!publishRules(oldEntity.getApp(), oldEntity.getIp(), oldEntity.getPort())) {             logger.warn(＂Publish degrade rules failed, app={}＂, oldEntity.getApp());         }         return Result.ofSuccess(id);     }      private boolean publishRules(String app, String ip, Integer port) {         /*List rules = repository.findAllByMachine(MachineInfo.of(app, ip, port));         return sentinelApiClient.setDegradeRuleOfMachine(app, ip, port, rules);*/         List rules = repository.findAllByApp(app);         try {             rulePublisher.publish(app, rules);         } catch (Exception e) {             logger.error(＂Failed to publish nacos, app={}＂, app);             logger.error(＂error is : ＂,e);         }         return true;     }      private  Result checkEntityInternal(DegradeRuleEntity entity) {         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;     } }
　　5.maven打包
　　重新打包sentinel-dashboard模块mvn clean package
　　6.配置文件修改
　　application.properties添加nacos配置项#nacos服务地址 sentinel.nacos.serverAddr=127.0.0.1:8848 #nacos命名空间 sentinel.nacos.namespacec= #sentinel.nacos.username= #sentinel.nacos.password=应用端集成
　　1.引入依赖     com.alibaba.cloud     spring-cloud-starter-alibaba-sentinel 
　　如果是maven多模块工程，父pom中添加alibaba的父pom依赖                                    com.alibaba.cloud             spring-cloud-alibaba-dependencies             2.2.6.RELEASE             pom             import               
　　2.注解支持
　　Sentinel 提供了 @SentinelResource 注解用于定义资源，实现资源的流控/熔断降级处理。
　　注意：注解方式埋点不支持 private 方法。@Service @Slf4j public class TestService {     /**      * 定义sayHello资源的方法，流控/熔断降级处理逻辑      * @param name      * @return      */     @SentinelResource(value = ＂sayHello＂,blockHandler = ＂sayHelloBlockHandler＂,fallback = ＂sayHelloFallback＂)     public String sayHello(String name) {         if(＂fallback＂.equalsIgnoreCase(name)){             throw new RuntimeException(＂fallback＂);         }         return ＂Hello, ＂ + name;     }      /**      * 被流控后处理方法。      * 1. @SentinelResource 注解blockHandler设置，值为函数方法名      * 2. blockHandler 函数访问范围需要是 public，返回类型需要与原方法相匹配，参数类型需要和原方法相匹配并且最后加一个额外的参数，类型为 BlockException。      * 3. blockHandler 函数默认需要和原方法在同一个类中。若希望使用其他类的函数，则可以指定 blockHandlerClass 为对应的类的 Class 对象，注意对应的函数必需为 static 函数，否则无法解析。      * @param name      * @param blockException      * @return      */     public String sayHelloBlockHandler(String name, BlockException blockException){         log.warn(＂已开启流控＂,blockException);         return ＂流控后的返回值＂;     }      /**      * 被降级后处理方法      * 注意！！！：如果blockHandler和fallback都配置，熔断降级规则生效，触发熔断,在熔断时长定义时间内，只有blockHandler生效      * 1. @SentinelResource 注解fallback设置，值为函数方法名      * 2. 用于在抛出异常的时候提供 fallback 处理逻辑。fallback 函数可以针对所有类型的异常（除了 exceptionsToIgnore 里面排除掉的异常类型）进行处理      * 3. 返回值类型必须与原函数返回值类型一致；      * 4. 方法参数列表需要和原函数一致，或者可以额外多一个 Throwable 类型的参数用于接收对应的异常。      * 5. allback 函数默认需要和原方法在同一个类中。若希望使用其他类的函数，则可以指定 fallbackClass 为对应的类的 Class 对象，注意对应的函数必需为 static 函数，否则无法解析。      * @param name      * @param throwable      * @return      */     public String sayHelloFallback(String name, Throwable throwable){         log.warn(＂已降级＂,throwable);         return ＂降级后的返回值＂;     } }
　　流控和降级处理逻辑定义详见代码注释。
　　@SentinelResource还包含其他可能使用的属性：exceptionsToIgnore（since 1.6.0）：用于指定哪些异常被排除掉，不会计入异常统计中，也不会进入 fallback 逻辑中，而是会原样抛出。exceptionsToTrace：用于指定处理的异常。默认为Throwable.class。可设置自定义需要处理的其他异常类。
　　3.添加配置
　　application.yml文件添加以下配置spring:   application:     name: demo-sentinel   cloud:     sentinel: #阿里sentinel配置项       transport:         # spring.cloud.sentinel.transport.port 端口配置会在应用对应的机器上启动一个 Http Server，         # 该 Server 会与 Sentinel 控制台做交互。比如 Sentinel 控制台添加了一个限流规则，会把规则数据 push 给这个 Http Server 接收，         # Http Server 再将规则注册到 Sentinel 中。 #        port: 8719         dashboard: localhost:8080       datasource:         ds1: # 数据源标识key，可以随意命名，保证唯一即可           nacos: #nacos 数据源-流控规则配置             server-addr: localhost:8848 #            username: nacos #            password: nacos             data-id: ${spring.application.name}-flow-rules             group-id: SENTINEL_GROUP             data-type: json             #flow、degrade、param-flow             rule-type: flow         ds2:           nacos: #nacos 数据源-熔断降级规则配置             server-addr: localhost:8848 #            username: nacos #            password: nacos             data-id: ${spring.application.name}-degrade-rules             group-id: SENTINEL_GROUP             data-type: json             #flow、degrade、param-flow             rule-type: degrade验证
　　启动sentinel-dashboard。
　　应用端集成Sentinel SDK，访问添加了降级逻辑处理的接口地址。
　　访问sentinel-dashboard web页面: http://localhost:8080/ 。在界面，添加相应流控和熔断规则。
　　Nacos管理界面查看：http://localhost:8848/nacos 。 可以看到自动生成了两个配置界面，分别对应流控和熔断配置
　　点击规则详情，查看规则信息
　　规则json对象信息如下：[     {         ＂app＂: ＂***-sentinel＂,         ＂clusterConfig＂: {             ＂acquireRefuseStrategy＂: 0,             ＂clientOfflineTime＂: 2000,             ＂fallbackToLocalWhenFail＂: true,             ＂resourceTimeout＂: 2000,             ＂resourceTimeoutStrategy＂: 0,             ＂sampleCount＂: 10,             ＂strategy＂: 0,             ＂thresholdType＂: 0,             ＂windowIntervalMs＂: 1000         },         ＂clusterMode＂: false,         ＂controlBehavior＂: 0,         ＂count＂: 4000,         ＂gmtCreate＂: 1677065845653,         ＂gmtModified＂: 1677065845653,         ＂grade＂: 1,         ＂id＂: 1,         ＂ip＂: ＂192.168.56.1＂,         ＂limitApp＂: ＂default＂,         ＂port＂: 8720,         ＂resource＂: ＂sayHello2＂,         ＂strategy＂: 0     },     {         ＂app＂: ＂***-sentinel＂,         ＂clusterConfig＂: {             ＂acquireRefuseStrategy＂: 0,             ＂clientOfflineTime＂: 2000,             ＂fallbackToLocalWhenFail＂: true,             ＂resourceTimeout＂: 2000,             ＂resourceTimeoutStrategy＂: 0,             ＂sampleCount＂: 10,             ＂strategy＂: 0,             ＂thresholdType＂: 0,             ＂windowIntervalMs＂: 1000         },         ＂clusterMode＂: false,         ＂controlBehavior＂: 0,         ＂count＂: 1000,         ＂gmtCreate＂: 1677057866855,         ＂gmtModified＂: 1677065997762,         ＂grade＂: 1,         ＂id＂: 3,         ＂ip＂: ＂192.168.56.1＂,         ＂limitApp＂: ＂default＂,         ＂port＂: 8720,         ＂resource＂: ＂sayHello＂,         ＂strategy＂: 0     },     {         ＂app＂: ＂***-sentinel＂,         ＂clusterConfig＂: {             ＂acquireRefuseStrategy＂: 0,             ＂clientOfflineTime＂: 2000,             ＂fallbackToLocalWhenFail＂: true,             ＂resourceTimeout＂: 2000,             ＂resourceTimeoutStrategy＂: 0,             ＂sampleCount＂: 10,             ＂strategy＂: 0,             ＂thresholdType＂: 0,             ＂windowIntervalMs＂: 1000         },         ＂clusterMode＂: false,         ＂controlBehavior＂: 0,         ＂count＂: 2,         ＂gmtCreate＂: 1677117433499,         ＂gmtModified＂: 1677117433499,         ＂grade＂: 1,         ＂id＂: 6,         ＂ip＂: ＂192.168.56.1＂,         ＂limitApp＂: ＂default＂,         ＂port＂: 8720,         ＂resource＂: ＂/ping＂,         ＂strategy＂: 0     } ]