摘要：在之前的練習(xí)中，只要應(yīng)用重啟，就需要重新配置，這樣在我們實(shí)際的項(xiàng)目是非常不實(shí)用的，那么有沒有辦法把我們配置的規(guī)則保存下來呢答案是，那么接下來，給大家來介紹如何將規(guī)則持久化。重新啟動(dòng)測試效果添加流控規(guī)則查看同步的配置

在之前的練習(xí)中，只要應(yīng)用重啟，就需要重新配置，這樣在我們實(shí)際的項(xiàng)目是非常不實(shí)用的，那么有沒有辦法把我們配置的規(guī)則保存下來呢？答案是YES，那么接下來，給大家來介紹如何將Sentinel規(guī)則持久化。

Document: 傳送門

File Datasource(文件存儲(chǔ))

Pull 模式

Push 模式

Nacos configuration

Apollo

File Datasource

Pull 模式

原理：
擴(kuò)展寫數(shù)據(jù)源（WritableDataSource）， 客戶端主動(dòng)向某個(gè)規(guī)則管理中心定期輪詢拉取規(guī)則，這個(gè)規(guī)則中心可以是 RDBMS、文件 等
pull 模式的數(shù)據(jù)源（如本地文件、RDBMS 等）一般是可寫入的。使用時(shí)需要在客戶端注冊數(shù)據(jù)源：將對應(yīng)的讀數(shù)據(jù)源注冊至對應(yīng)的 RuleManager，將寫數(shù)據(jù)源注冊至 transport 的 WritableDataSourceRegistry 中。

過程如下：

Pull Demo

Step 1: 添加配置

    
        com.alibaba.csp
        sentinel-datasource-extension
    

Step 2: 編寫持久化代碼，實(shí)現(xiàn)com.alibaba.csp.sentinel.init.InitFunc

代碼參考自：傳送門

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 : 自定義Sentinel存儲(chǔ)文件數(shù)據(jù)源加載類
 *
 * @author Isaac.Zhang | 若初
 * @since 2019/7/21
 */
public class FileDataSourceInit implements InitFunc {
    @Override
    public void init() throws Exception {
        // TIPS: 如果你對這個(gè)路徑不喜歡，可修改為你喜歡的路徑
        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);
        // 流控規(guī)則
        ReadableDataSource> flowRuleRDS = new FileRefreshableDataSource<>(
                flowRulePath,
                flowRuleListParser
        );
        // 將可讀數(shù)據(jù)源注冊至FlowRuleManager
        // 這樣當(dāng)規(guī)則文件發(fā)生變化時(shí)，就會(huì)更新規(guī)則到內(nèi)存
        FlowRuleManager.register2Property(flowRuleRDS.getProperty());
        WritableDataSource> flowRuleWDS = new FileWritableDataSource<>(
                flowRulePath,
                this::encodeJson
        );
        // 將可寫數(shù)據(jù)源注冊至transport模塊的WritableDataSourceRegistry中
        // 這樣收到控制臺(tái)推送的規(guī)則時(shí)，Sentinel會(huì)先更新到內(nèi)存，然后將規(guī)則寫入到文件中
        WritableDataSourceRegistry.registerFlowDataSource(flowRuleWDS);

        // 降級(jí)規(guī)則
        ReadableDataSource> degradeRuleRDS = new FileRefreshableDataSource<>(
                degradeRulePath,
                degradeRuleListParser
        );
        DegradeRuleManager.register2Property(degradeRuleRDS.getProperty());
        WritableDataSource> degradeRuleWDS = new FileWritableDataSource<>(
                degradeRulePath,
                this::encodeJson
        );
        WritableDataSourceRegistry.registerDegradeDataSource(degradeRuleWDS);

        // 系統(tǒng)規(guī)則
        ReadableDataSource> systemRuleRDS = new FileRefreshableDataSource<>(
                systemRulePath,
                systemRuleListParser
        );
        SystemRuleManager.register2Property(systemRuleRDS.getProperty());
        WritableDataSource> systemRuleWDS = new FileWritableDataSource<>(
                systemRulePath,
                this::encodeJson
        );
        WritableDataSourceRegistry.registerSystemDataSource(systemRuleWDS);

        // 授權(quán)規(guī)則
        ReadableDataSource> authorityRuleRDS = new FileRefreshableDataSource<>(
                flowRulePath,
                authorityRuleListParser
        );
        AuthorityRuleManager.register2Property(authorityRuleRDS.getProperty());
        WritableDataSource> authorityRuleWDS = new FileWritableDataSource<>(
                authorityRulePath,
                this::encodeJson
        );
        WritableDataSourceRegistry.registerAuthorityDataSource(authorityRuleWDS);

        // 熱點(diǎn)參數(shù)規(guī)則
        ReadableDataSource> hotParamFlowRuleRDS = new FileRefreshableDataSource<>(
                hotParamFlowRulePath,
                hotParamFlowRuleListParser
        );
        ParamFlowRuleManager.register2Property(hotParamFlowRuleRDS.getProperty());
        WritableDataSource> paramFlowRuleWDS = new FileWritableDataSource<>(
                hotParamFlowRulePath,
                this::encodeJson
        );
        ModifyParamFlowRulesCommandHandler.setWritableDataSource(paramFlowRuleWDS);
    }

    /**
     * 流控規(guī)則對象轉(zhuǎn)換
     */
    private Converter> flowRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );
    /**
     * 降級(jí)規(guī)則對象轉(zhuǎn)換
     */
    private Converter> degradeRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );
    /**
     * 系統(tǒng)規(guī)則對象轉(zhuǎn)換
     */
    private Converter> systemRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );

    /**
     * 授權(quán)規(guī)則對象轉(zhuǎn)換
     */
    private Converter> authorityRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );

    /**
     * 熱點(diǎn)規(guī)則對象轉(zhuǎn)換
     */
    private Converter> hotParamFlowRuleListParser = source -> JSON.parseObject(
            source,
            new TypeReference>() {
            }
    );

    /**
     * 創(chuàng)建目錄
     *
     * @param filePath
     */
    private void mkdirIfNotExits(String filePath) {
        File file = new File(filePath);
        if (!file.exists()) {
            file.mkdirs();
        }
    }

    /**
     * 創(chuàng)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: 啟用上述代碼

resource 目錄下創(chuàng)建 resources/META-INF/services 目錄并創(chuàng)建文件com.alibaba.csp.sentinel.init.InitFunc ，內(nèi)容為：

com.sxzhongf.sharedcenter.configuration.sentinel.datasource.FileDataSourceInit

Pull 優(yōu)缺點(diǎn)

優(yōu)點(diǎn)

簡單，無任何依賴

沒有額外依賴

缺點(diǎn)

不保證一致性（規(guī)則是使用FileRefreshableDataSource定時(shí)更新，會(huì)有延遲）

實(shí)時(shí)性不保證（規(guī)則是使用FileRefreshableDataSource定時(shí)更新）

拉取過于頻繁也可能會(huì)有性能問題

由于文件存儲(chǔ)于本地，容易丟失

參考資料：

ITMUCH

Sentinel WIKI

Push 模式

推薦通過控制臺(tái)設(shè)置規(guī)則后將規(guī)則推送到統(tǒng)一的規(guī)則中心，客戶端實(shí)現(xiàn) ReadableDataSource接口端監(jiān)聽規(guī)則中心實(shí)時(shí)獲取變更，流程如下：

實(shí)現(xiàn)原理

控制臺(tái)推送規(guī)則到Nacos/遠(yuǎn)程配置中心

Sentinel client 艦艇Nacos配置變化，更新本地緩存

shared_center service 加工

添加依賴

  
      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
            # 規(guī)則類型，取值見：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 規(guī)則改造主要通過2個(gè)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項(xiàng)目下的POM文件

    
    
        com.alibaba.csp
        sentinel-datasource-nacos
        
        
    

偷懶模式：復(fù)制sentinel-dashboard項(xiàng)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中的默認(rèn)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;

打開 /Sentinel-1.6.2/sentinel-dashboard/src/main/webapp/resources/app/scripts/directives/sidebar/sidebar.html文件，修改代碼：

            
              


---

改為

  

    
        NACOS 流控規(guī)則 V1
  

Dashboard中要修改的代碼已經(jīng)好了。

重新啟動(dòng) Sentinel-dashboard mvn clean package -DskipTests

測試效果

Sentinel 添加流控規(guī)則：

Nacos 查看同步的配置：