【Sentinel】Sentinel配置zk持久化

代码

import cn.hutool.core.util.StrUtil;
import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
import com.alibaba.csp.sentinel.datasource.zookeeper.ZookeeperDataSource;
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.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.zookeeper.ZookeeperProperties;
import org.springframework.stereotype.Component;import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.List;@Component
public class ZkDataSourceConfig {@Value("${spring.application.name}")private String appname;@Value("${spring.profiles.active}")private String profile;@Resourceprivate ZookeeperProperties zookeeperProperties;@PostConstructpublic void init() {loadRules(zookeeperProperties.getConnectString());}private void loadRules(String remoteAddress) {// 规则会持久化到zk的/groupId/flowDataId节点// groupId和和flowDataId可以用/开头也可以不用// 建议不用以/开头，目的是为了如果从Zookeeper切换到Nacos的话，只需要改数据源类名就可以String groupId = StrUtil.format("sentinel/{}:{}", appname, profile);ReadableDataSource<String, List<FlowRule>> flowRuleDataSource = new ZookeeperDataSource<>(remoteAddress, groupId, "FlowRule",// source 就是从 zookeeper 中读出来的字符串source -> JSON.parseObject(source, new TypeReference<List<FlowRule>>() {}));//限流FlowRuleManager.register2Property(flowRuleDataSource.getProperty());ReadableDataSource<String, List<DegradeRule>> degradeRuleDataSource = new ZookeeperDataSource<>(remoteAddress, groupId, "DegradeRule",// source 就是从 zookeeper 中读出来的字符串source -> JSON.parseObject(source, new TypeReference<List<DegradeRule>>() {}));//降级DegradeRuleManager.register2Property(degradeRuleDataSource.getProperty());}
}

ZK配置参考

/sentinel/应用名:环境=FlowRule=[{"resource": "资源1", "limitApp": "default", "grade": 1, "count": 40.0, "strategy": 0, "controlBehavior": 2, "maxQueueingTimeMs": 100000 }, {"resource": "资源2", "limitApp": "default", "grade": 1, "count": 40.0, "strategy": 0, "controlBehavior": 2, "maxQueueingTimeMs": 100000 }, {"resource": "资源3", "limitApp": "default", "grade": 1, "count": 10.0, "strategy": 0, "controlBehavior": 2, "maxQueueingTimeMs": 100000 } ]

使用

public class demo {public static void main(String[] args) {// 定义规则initFlowRules();//用SphU.entry()的形式定义资源while (true) {try (Entry entry = SphU.entry("myResource")) {//与规则定义中的rule.setResource("myResource")一致// 被保护的业务逻辑...System.out.println("业务资源访问成功！");} catch (BlockException ex) {// 处理被流控的逻辑：限流或降级...System.out.println("资源访问失败！！！");} finally {if (entry != null) {entry.exit();//必须退出资源调用}}}//用SphO.entry()的形式定义资源while (true) {if(SphO.entry("myResource")){//与规则定义中的rule.setResource("myResource")一致try{// 被保护的业务逻辑...System.out.println("业务资源访问成功！");} catch (BlockException ex) {// 处理被流控的逻辑：限流或降级...System.out.println("资源访问失败！！！");}finally{SphO.exit();//必须退出资源调用}}}//上面两种方式对代码侵入性很高，可用注解的方式定义资源while(true){getUserById("111");}}//文章开始通过zk加载配置，此处通过代码定义规则	//定义规则 private static void initFlowRules(){List<FlowRule> rules = new ArrayList<>();// 存储规则 FlowRuleFlowRule rule = new FlowRule();rule.setResource("myResource");	// 指定限流规则作用于哪个资源上，资源名为字符串，可为任意有标识意义的方法名/接口名/其他字符串，此处资源名为"myResource"rule.setGrade(RuleConstant.FLOW_GRADE_QPS);	// 限流类型为QPS模式：限制QPSrule.setCount(10);	   // QPS不得超出10rule.setLimitApp("default");	// 针对的调用来源，default代表不区分来源rules.add(rule);FlowRuleManager.loadRules(rules);// 加载规则}//定义"myResource"资源，并设置违背sentinel流控规则时的处理方法handlerException()@SentinelResource(value="myResource",blockHandler="handlerException")public User getUserById(String id){return new User("数据库用户")；}//注意：此处理方法的参数必须和定义资源的方法getUserById参数一致（）同时加上【BlockException exception】参数public User handlerException(String id,BlockException exception){return new User("流控用户");}
}

Entry entry = null;
try {entry = SphU.entry("myResource"); //此处说明资源// 被保护的业务逻辑...
} catch (BlockException e1) {// 资源访问阻止，被限流或被降级,进行相应的处理操作...
} finally {if (entry != null) {entry.exit();}
}