[Spring-Cloud-Alibaba] Sentinel 规则持久化

摘要：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，那么接下来，给大家来介绍如何将规则持久化。重新启动测试效果添加流控规则查看同步的配置

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：

Pull Demo

Step 1: 添加配置

    
        com.alibaba.csp
        sentinel-datasource-extension
    

Step 2: 编写持久化代码，实现com.alibaba.csp.sentinel.init.InitFunc

代码参考自：传送门

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 Isaac.Zhang | 若初
 * @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> 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> 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> degradeRuleRDS = new FileRefreshableDataSource<>(
                degradeRulePath,
                degradeRuleListParser
        );
        DegradeRuleManager.register2Property(degradeRuleRDS.getProperty());
        WritableDataSource> degradeRuleWDS = new FileWritableDataSource<>(
                degradeRulePath,
                this::encodeJson
        );
        WritableDataSourceRegistry.registerDegradeDataSource(degradeRuleWDS);

        // 系统规则
        ReadableDataSource> systemRuleRDS = new FileRefreshableDataSource<>(
                systemRulePath,
                systemRuleListParser
        );
        SystemRuleManager.register2Property(systemRuleRDS.getProperty());
        WritableDataSource> systemRuleWDS = new FileWritableDataSource<>(
                systemRulePath,
                this::encodeJson
        );
        WritableDataSourceRegistry.registerSystemDataSource(systemRuleWDS);

        // 授权规则
        ReadableDataSource> authorityRuleRDS = new FileRefreshableDataSource<>(
                flowRulePath,
                authorityRuleListParser
        );
        AuthorityRuleManager.register2Property(authorityRuleRDS.getProperty());
        WritableDataSource> authorityRuleWDS = new FileWritableDataSource<>(
                authorityRulePath,
                this::encodeJson
        );
        WritableDataSourceRegistry.registerAuthorityDataSource(authorityRuleWDS);

        // 热点参数规则
        ReadableDataSource> hotParamFlowRuleRDS = new FileRefreshableDataSource<>(
                hotParamFlowRulePath,
                hotParamFlowRuleListParser
        );
        ParamFlowRuleManager.register2Property(hotParamFlowRuleRDS.getProperty());
        WritableDataSource> paramFlowRuleWDS = new FileWritableDataSource<>(
                hotParamFlowRulePath,
                this::encodeJson
        );
        ModifyParamFlowRulesCommandHandler.setWritableDataSource(paramFlowRuleWDS);
    }

    /**
     * 流控规则对象转换
     */
    private Converter> flowRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );
    /**
     * 降级规则对象转换
     */
    private Converter> degradeRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );
    /**
     * 系统规则对象转换
     */
    private Converter> systemRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );

    /**
     * 授权规则对象转换
     */
    private Converter> authorityRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );

    /**
     * 热点规则对象转换
     */
    private Converter> hotParamFlowRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );

    /**
     * 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  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

简单，无任何依赖

没有额外依赖

缺点

不保证一致性（规则是使用FileRefreshableDataSource定时更新，会有延迟）

实时性不保证（规则是使用FileRefreshableDataSource定时更新）

拉取过于频繁也可能会有性能问题

由于文件存储于本地，容易丢失

参考资料：

ITMUCH

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：

实现原理

控制台推送规则到Nacos/远程配置中心

Sentinel client 舰艇Nacos配置变化，更新本地缓存

shared_center service 加工

添加依赖

  
      com.alibaba.csp
      sentinel-datasource-nacos
  

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

Download Sentinel Source Code

修改原sentinel-dashboard项目下的POM文件

    
    
        com.alibaba.csp
        sentinel-datasource-nacos
        
        
    

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/nacos到 src/main/java/com/alibaba/csp/sentinel/dashboard/rule下

修改controller中的默认provider & publisher

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

    @Autowired
    // @Qualifier("flowRuleDefaultProvider")
        @Qualifier("flowRuleNacosProvider")
    private DynamicRuleProvider> ruleProvider;
    @Autowired
        // @Qualifier("flowRuleDefaultPublisher")
    @Qualifier("flowRuleNacosPublisher")
    private DynamicRulePublisher> 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：

            
              


---

改为

  

    
        NACOS 流控规则 V1
  

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：

Nacos 查看同步的配置：