在之前的练习中,只要应用重启,就需要重新配置,这样在我们实际的项目是非常不实用的,那么有没有办法把我们配置的规则保存下来呢?答案是YES,那么接下来,给大家来介绍如何将Sentinel规则持久化。

Document: 传送门

  • File Datasource(文件存储)
    • Pull 模式
    • Push 模式
  • Nacos configuration
  • Apollo
File Datasource
Pull 模式

原理:
扩展写数据源(WritableDataSource), 客户端主动向某个规则管理中心定期轮询拉取规则,这个规则中心可以是 RDBMS、文件 等
pull 模式的数据源(如本地文件、RDBMS 等)一般是可写入的。使用时需要在客户端注册数据源:将对应的读数据源注册至对应的 RuleManager,将写数据源注册至 transport 的 WritableDataSourceRegistry 中。

过程如下:

[Spring-Cloud-Alibaba] Sentinel 规则持久化

Pull Demo
  • Step 1: 添加配置

      <dependency>
          <groupId>com.alibaba.csp</groupId>
          <artifactId>sentinel-datasource-extension</artifactId>
      </dependency>
  • Step 2: 编写持久化代码,实现com.alibaba.csp.sentinel.init.InitFunc

    import com.alibaba.csp.sentinel.command.handler.ModifyParamFlowRulesCommandHandler;
    import com.alibaba.csp.sentinel.datasource.*;
    import com.alibaba.csp.sentinel.init.InitFunc;
    import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRule;
    import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRuleManager;
    import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
    import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRuleManager;
    import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
    import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
    import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowRule;
    import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowRuleManager;
    import com.alibaba.csp.sentinel.slots.system.SystemRule;
    import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
    import com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry;
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.TypeReference;
    
    import java.io.File;
    import java.io.IOException;
    import java.util.List;
    
    /**
    * FileDataSourceInit for : 自定义Sentinel存储文件数据源加载类
    *
    * @author <a href="mailto:magicianisaac@gmail.com">Isaac.Zhang | 若初</a>
    * @since 2019/7/21
    */
    public class FileDataSourceInit implements InitFunc {
      @Override
      public void init() throws Exception {
          // TIPS: 如果你对这个路径不喜欢,可修改为你喜欢的路径
          String ruleDir = System.getProperty("user.home") + "/sentinel/rules";
          String flowRulePath = ruleDir + "/flow-rule.json";
          String degradeRulePath = ruleDir + "/degrade-rule.json";
          String systemRulePath = ruleDir + "/system-rule.json";
          String authorityRulePath = ruleDir + "/authority-rule.json";
          String hotParamFlowRulePath = ruleDir + "/param-flow-rule.json";
    
          this.mkdirIfNotExits(ruleDir);
          this.createFileIfNotExits(flowRulePath);
          this.createFileIfNotExits(degradeRulePath);
          this.createFileIfNotExits(systemRulePath);
          this.createFileIfNotExits(authorityRulePath);
          this.createFileIfNotExits(hotParamFlowRulePath);
          // 流控规则
          ReadableDataSource<String, List<FlowRule>> flowRuleRDS = new FileRefreshableDataSource<>(
                  flowRulePath,
                  flowRuleListParser
          );
          // 将可读数据源注册至FlowRuleManager
          // 这样当规则文件发生变化时,就会更新规则到内存
          FlowRuleManager.register2Property(flowRuleRDS.getProperty());
          WritableDataSource<List<FlowRule>> flowRuleWDS = new FileWritableDataSource<>(
                  flowRulePath,
                  this::encodeJson
          );
          // 将可写数据源注册至transport模块的WritableDataSourceRegistry中
          // 这样收到控制台推送的规则时,Sentinel会先更新到内存,然后将规则写入到文件中
          WritableDataSourceRegistry.registerFlowDataSource(flowRuleWDS);
    
          // 降级规则
          ReadableDataSource<String, List<DegradeRule>> degradeRuleRDS = new FileRefreshableDataSource<>(
                  degradeRulePath,
                  degradeRuleListParser
          );
          DegradeRuleManager.register2Property(degradeRuleRDS.getProperty());
          WritableDataSource<List<DegradeRule>> degradeRuleWDS = new FileWritableDataSource<>(
                  degradeRulePath,
                  this::encodeJson
          );
          WritableDataSourceRegistry.registerDegradeDataSource(degradeRuleWDS);
    
          // 系统规则
          ReadableDataSource<String, List<SystemRule>> systemRuleRDS = new FileRefreshableDataSource<>(
                  systemRulePath,
                  systemRuleListParser
          );
          SystemRuleManager.register2Property(systemRuleRDS.getProperty());
          WritableDataSource<List<SystemRule>> systemRuleWDS = new FileWritableDataSource<>(
                  systemRulePath,
                  this::encodeJson
          );
          WritableDataSourceRegistry.registerSystemDataSource(systemRuleWDS);
    
          // 授权规则
          ReadableDataSource<String, List<AuthorityRule>> authorityRuleRDS = new FileRefreshableDataSource<>(
                  flowRulePath,
                  authorityRuleListParser
          );
          AuthorityRuleManager.register2Property(authorityRuleRDS.getProperty());
          WritableDataSource<List<AuthorityRule>> authorityRuleWDS = new FileWritableDataSource<>(
                  authorityRulePath,
                  this::encodeJson
          );
          WritableDataSourceRegistry.registerAuthorityDataSource(authorityRuleWDS);
    
          // 热点参数规则
          ReadableDataSource<String, List<ParamFlowRule>> hotParamFlowRuleRDS = new FileRefreshableDataSource<>(
                  hotParamFlowRulePath,
                  hotParamFlowRuleListParser
          );
          ParamFlowRuleManager.register2Property(hotParamFlowRuleRDS.getProperty());
          WritableDataSource<List<ParamFlowRule>> paramFlowRuleWDS = new FileWritableDataSource<>(
                  hotParamFlowRulePath,
                  this::encodeJson
          );
          ModifyParamFlowRulesCommandHandler.setWritableDataSource(paramFlowRuleWDS);
      }
    
      /**
       * 流控规则对象转换
       */
      private Converter<String, List<FlowRule>> flowRuleListParser = source -> JSON.parseObject(
              source,
              new TypeReference<List<FlowRule>>() {
              }
      );
      /**
       * 降级规则对象转换
       */
      private Converter<String, List<DegradeRule>> degradeRuleListParser = source -> JSON.parseObject(
              source,
              new TypeReference<List<DegradeRule>>() {
              }
      );
      /**
       * 系统规则对象转换
       */
      private Converter<String, List<SystemRule>> systemRuleListParser = source -> JSON.parseObject(
              source,
              new TypeReference<List<SystemRule>>() {
              }
      );
    
      /**
       * 授权规则对象转换
       */
      private Converter<String, List<AuthorityRule>> authorityRuleListParser = source -> JSON.parseObject(
              source,
              new TypeReference<List<AuthorityRule>>() {
              }
      );
    
      /**
       * 热点规则对象转换
       */
      private Converter<String, List<ParamFlowRule>> hotParamFlowRuleListParser = source -> JSON.parseObject(
              source,
              new TypeReference<List<ParamFlowRule>>() {
              }
      );
    
      /**
       * 创建目录
       *
       * @param filePath
       */
      private void mkdirIfNotExits(String filePath) {
          File file = new File(filePath);
          if (!file.exists()) {
              file.mkdirs();
          }
      }
    
      /**
       * 创建文件
       *
       * @param filePath
       * @throws IOException
       */
      private void createFileIfNotExits(String filePath) throws IOException {
          File file = new File(filePath);
          if (!file.exists()) {
              file.createNewFile();
          }
      }
    
      private <T> String encodeJson(T t) {
          return JSON.toJSONString(t);
      }
    }
  • Step 3: 启用上述代码

    resource 目录下创建 resources/META-INF/services 目录并创建文件com.alibaba.csp.sentinel.init.InitFunc ,内容为:

    com.sxzhongf.sharedcenter.configuration.sentinel.datasource.FileDataSourceInit
Pull 优缺点
  • 优点
    1. 简单,无任何依赖
    2. 没有额外依赖
  • 缺点
    1. 不保证一致性(规则是使用FileRefreshableDataSource定时更新,会有延迟)
    2. 实时性不保证(规则是使用FileRefreshableDataSource定时更新)
    3. 拉取过于频繁也可能会有性能问题
    4. 由于文件存储于本地,容易丢失
  • 参考资料:
    1. ITMUCH
    2. Sentinel WIKI
Push 模式

推荐通过控制台设置规则后将规则推送到统一的规则中心,客户端实现 ReadableDataSource接口端监听规则中心实时获取变更,流程如下:

<img src="https://user-images.githubusercontent.com/9434884/45406233-645e8380-b698-11e8-8199-0c917403238f.png" width="500" />

  • 实现原理

    1. 控制台推送规则到Nacos/远程配置中心
    2. Sentinel client 舰艇Nacos配置变化,更新本地缓存
  • shared_center service 加工

    1. 添加依赖
      <dependency>
          <groupId>com.alibaba.csp</groupId>
          <artifactId>sentinel-datasource-nacos</artifactId>
      </dependency>
    1. 添加配置
    spring:
      cloud:
        sentinel:
          datasource:
            sxzhongf_flow:
              nacos:
                server-addr: localhost:8848
                dataId: ${spring.application.name}-flow-rules
                groupId: SENTINEL_GROUP
                # 规则类型,取值见:org.springframework.cloud.alibaba.sentinel.datasource.RuleType
                rule_type: flow
            sxzhongf_degrade:
              nacos:
                server-addr: localhost:8848
                dataId: ${spring.application.name}-degrade-rules
                groupId: SENTINEL_GROUP
                rule-type: degrade
  • Sentinel dashboard 加工

    Dashboard 规则改造主要通过2个接口:

    com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider & com.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher

        <!-- for Nacos rule publisher sample -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
            <!--注释掉原文件中的scope,让其不仅在test的时候生效-->
            <!--<scope>test</scope>-->
        </dependency>
    • 偷懒模式:复制sentinel-dashboard项目下test下的nacos包(

    src/test/java/com/alibaba/csp/sentinel/dashboard/rule/nacossrc/main/java/com/alibaba/csp/sentinel/dashboard/rule

    • 修改controller中的默认provider & publisher

    com.alibaba.csp.sentinel.dashboard.controller.v2.FlowControllerV2

        @Autowired
        // @Qualifier("flowRuleDefaultProvider")
            @Qualifier("flowRuleNacosProvider")
        private DynamicRuleProvider<List<FlowRuleEntity>> ruleProvider;
        @Autowired
            // @Qualifier("flowRuleDefaultPublisher")
        @Qualifier("flowRuleNacosPublisher")
        private DynamicRulePublisher<List<FlowRuleEntity>> rulePublisher;
    • 打开 /Sentinel-1.6.2/sentinel-dashboard/src/main/webapp/resources/app/scripts/directives/sidebar/sidebar.html文件,修改代码:
    <!--<li ui-sref-active="active">-->
                <!--<a ui-sref="dashboard.flow({app: entry.app})">-->
                  <!--<i class="glyphicon glyphicon-filter"></i>  流控规则 V1</a>-->
    <!--</li>-->
    
    ---
    
    改为
    
      <li ui-sref-active="active">
        <a ui-sref="dashboard.flow({app: entry.app})">
          <i class="glyphicon glyphicon-filter"></i>  NACOS 流控规则 V1</a>
      </li>

    Dashboard中要修改的代码已经好了。

  • 重新启动 Sentinel-dashboard mvn clean package -DskipTests

  • 测试效果

    Sentinel 添加流控规则:

    [Spring-Cloud-Alibaba] Sentinel 规则持久化

    Nacos 查看同步的配置:

    [Spring-Cloud-Alibaba] Sentinel 规则持久化