B站视频讲解
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文章目录
- 一、理论
- 二、实践
- 2-1、dashboard 请求Redis
- 2-1-1、依赖、配置文件引入
- 2-1-2、常量定义
- 2-1-3、改写唯一id
- 2-1-4、新Provider和Publisher
- 2-1-5、改写V2
- 2-2、应用服务改造
- 2-2-1、依赖、配置文件引入
- 2-2-2、注册监听器
- 三、源码获取
- 3-1、使用
- 3-2、获取方式
- 四、参考
上一篇讲Sentinel的时候,是用dashboard直接和服务进行交互,实时的新增/删除限流规则,所有的规则都存储在应用服务的内存中,每次重启服务之后再刷新dashboard就没有对应规则信息了。
这当然不是我们希望看到的,如果想要长久的保存规则,有且只有一个办法,那就是规则数据持久化。
一、理论
- 既然dashboard可以把规则推送到服务端,那服务端就可以拿到规则去持久化到硬盘上(文件、MySQL…),怎么说呢?这看起来不是个好办法,首先它很low,其次也不好解决分布式系统数据一致性的问题。
- 那换一种思路,dashboard先把规则推送给A,再由A把规则下发到各个具体的应用服务。这样A就相当于一种中心存储,解决了数据存储的问题,同时A实时下发给应用服务解决了数据一致性的问题。
这个A,官方给出了几种实现Nacos、ZooKeeper、Apollo、Redis。(理论上是可以自己去重写做到任何实现)
第一种方式就不推荐了,下面基于方式二来做实践,这里选用Redis来,主要是目前电脑只安装了Redis,原理是一样的。
下面是官方给出的图,要理解,是先把规则给到A,再由A去下发规则。(所以需要修改dashboard源码,让它先请求A)
想深入了解的可以参看下面的文档:
- https://github.com/alibaba/Sentinel/wiki/动态规则扩展
- https://github.com/alibaba/Sentinel/wiki/在生产环境中使用-Sentinel
二、实践
基于上面的分析,需要分两步改造
- 让dashboard把规则数据推送给Redis
- 应用服务接受Redis的下发(基于Redis的发布订阅功能)
注:会在Redis定义一个Key用来存储最终的规则数据,还会定义一个通道用来实时推送规则数据
2-1、dashboard 请求Redis
从Github下载dashboard源码:https://github.com/alibaba/Sentinel/releases
默认情况下,dashboard限流策略请求的是这个 v1 接口,官方还提供了一个 v2,这个v2就是持久化的接口,基于不同的持久化策略,只需要在 v2的版本里面替换对应的 DynamicRuleProvider、DynamicRulePublisher
2-1-1、依赖、配置文件引入
1、Redis-starter 引入
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId><version>${spring.boot.version}</version>
</dependency>
2、配置文件修改
spring.redis.host=127.0.0.1
spring.redis.port=6379
spring.redis.database=0
3、Redis配置
@Configuration
public class RedisConfig {@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();redisTemplate.setConnectionFactory(factory);redisTemplate.setEnableTransactionSupport(true);GenericJackson2JsonRedisSerializer jsonRedisSerializer = new GenericJackson2JsonRedisSerializer();StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();redisTemplate.setValueSerializer(jsonRedisSerializer);redisTemplate.setKeySerializer(stringRedisSerializer);redisTemplate.setHashKeySerializer(stringRedisSerializer);redisTemplate.setHashValueSerializer(jsonRedisSerializer);redisTemplate.afterPropertiesSet();return redisTemplate;}
}
2-1-2、常量定义
public final class Constants {// 最终规则是存储的keypublic static final String RULE_FLOW_PREFIX = "sentinel:rule:flow:xdx";// Redis的订阅发布功能,需要一个通道public static final String RULE_FLOW_CHANNEL_PREFIX = "sentinel:channel:flow:xdx";// 每一个规则都需要唯一id,基于Redis生成idpublic static final String RULE_FLOW_ID_KEY = "sentinel:id:flow:xdx";
}
2-1-3、改写唯一id
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;@Component
public class RedisIdGenerator {@Autowiredprivate RedisTemplate<String, Object> redisTemplate;public long nextId(String key) {return redisTemplate.opsForValue().increment(key, 1);}
}
2-1-4、新Provider和Publisher
Provider的目的是读取Redis的内存数据
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;
import com.alibaba.fastjson.JSON;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;import java.util.Collections;
import java.util.List;import static com.alibaba.csp.sentinel.dashboard.xdx.Constants.RULE_FLOW_PREFIX;@Component("flowRuleRedisProvider")
public class FlowRuleRedisProvider implements DynamicRuleProvider<List<FlowRuleEntity>> {private final Logger logger = LoggerFactory.getLogger(FlowRuleRedisProvider.class);@Autowiredprivate RedisTemplate<String, Object> redisTemplate;@Overridepublic List<FlowRuleEntity> getRules(String appName) throws Exception {Assert.notNull(appName, "应用名称不能为空");logger.info("拉取redis流控规则开始: {}", appName);String key = RULE_FLOW_PREFIX;String ruleStr = (String)redisTemplate.opsForValue().get(key);if(StringUtils.isEmpty(ruleStr)) {return Collections.emptyList();}List<FlowRuleEntity> rules = JSON.parseArray(ruleStr, FlowRuleEntity.class);logger.info("拉取redis流控规则成功, 规则数量: {}", rules.size());return rules;}
}
每次规则变动,都把最新规则存到Redis里面去,并使用Redis通道发布
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher;
import com.alibaba.fastjson.JSON;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;import java.util.List;import static com.alibaba.csp.sentinel.dashboard.xdx.Constants.RULE_FLOW_CHANNEL_PREFIX;
import static com.alibaba.csp.sentinel.dashboard.xdx.Constants.RULE_FLOW_PREFIX;@Component("flowRuleRedisPublisher")
public class FlowRuleRedisPublisher implements DynamicRulePublisher<List<FlowRuleEntity>> {private final Logger logger = LoggerFactory.getLogger(FlowRuleRedisPublisher.class);@Autowiredprivate RedisTemplate<String, Object> redisTemplate;@Overridepublic void publish(String app, List<FlowRuleEntity> rules) throws Exception {Assert.notNull(app, "应用名称不能为空");Assert.notEmpty(rules, "策略规则不为空");logger.info("推送流控规则开始, 应用名: {}, 规则数量: {}", app, rules.size());String ruleKey = RULE_FLOW_PREFIX;String ruleStr = JSON.toJSONString(rules);// 数据存储redisTemplate.opsForValue().set(ruleKey, ruleStr);// 数据发布redisTemplate.convertAndSend(RULE_FLOW_CHANNEL_PREFIX, ruleStr);}
}
2-1-5、改写V2
- 刚刚说默认是请求V1版本,这里为了简单,直接把V1的@RequestMapping注释,把V2的@RequestMapping改成V1(可以改前端,让它请求到V2)
- 把新 V1的Publisher和Provider改成新的Redis版本
- 下图也是每个类的位置
2-2、应用服务改造
- https://github.com/alibaba/Sentinel/wiki/动态规则扩展
- Sentinel 官方已经做了Redis适配,使用起来也很简单了
2-2-1、依赖、配置文件引入
1、新增pom文件
<dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-datasource-redis</artifactId><version>1.8.6</version>
</dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
2、配置文件
spring:redis:host: 127.0.0.1port: 6379
3、Redis 配置文件(和上面一样)
@Configuration
public class ConfigRedis {@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();redisTemplate.setConnectionFactory(factory);redisTemplate.setEnableTransactionSupport(true);GenericJackson2JsonRedisSerializer jsonRedisSerializer = new GenericJackson2JsonRedisSerializer();StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();redisTemplate.setValueSerializer(jsonRedisSerializer);redisTemplate.setKeySerializer(stringRedisSerializer);redisTemplate.setHashKeySerializer(stringRedisSerializer);redisTemplate.setHashValueSerializer(jsonRedisSerializer);redisTemplate.afterPropertiesSet();return redisTemplate;}
}
2-2-2、注册监听器
直接在启动类里面改造就好了
@SpringBootApplication
public class App11 implements ApplicationRunner {public static void main(String[] args) {SpringApplication.run(App11.class, args);}public static final String RULE_FLOW_PREFIX = "sentinel:rule:flow:xdx";public static final String RULE_FLOW_CHANNEL_PREFIX = "sentinel:channel:flow:xdx";@Overridepublic void run(ApplicationArguments args) {Converter<String ,List<FlowRule>> parser = source -> {List<FlowRule> flowRules = new ArrayList<>();if (source != null) {String replace = source.replace("\\", "");String substring = replace.substring(1, replace.length() - 1);flowRules = JSON.parseArray(substring, FlowRule.class);}return flowRules;};RedisConnectionConfig config = RedisConnectionConfig.builder().withHost("127.0.0.1").withPort(6379).build();ReadableDataSource<String, List<FlowRule>> redisDataSource = new RedisDataSource<>(config, RULE_FLOW_PREFIX, RULE_FLOW_CHANNEL_PREFIX, parser);FlowRuleManager.register2Property(redisDataSource.getProperty());System.out.println("redis-sentinel-持久化开启");}
}
三、源码获取
3-1、使用
下面是修改好的sentinel-dashboard和对应的应用服务,只需要修改两个服务中的Redis连接地址就可以使用,如果你的Redis是 默认的127.0.0.1 和 6379 则无需修改。
3-2、获取方式
- 关注微信公众号:小道仙97
- 回复关键字:Sentinel_xdx97
四、参考
- https://github.com/all4you/sentinel-tutorial/blob/master/sentinel-practice/sentinel-persistence-rules/sentinel-persistence-rules.md
- https://sentinelguard.io/zh-cn/blog/use-sentinel-dashboard-in-production.html
- https://github.com/alibaba/Sentinel/tree/master/sentinel-extension/sentinel-datasource-redis
- https://github.com/alibaba/Sentinel/wiki/%E5%8A%A8%E6%80%81%E8%A7%84%E5%88%99%E6%89%A9%E5%B1%95
- https://github.com/alibaba/Sentinel/tree/master/sentinel-extension/sentinel-datasource-redis
- https://www.jianshu.com/p/997a2255ff23
- https://github.com/alibaba/Sentinel/wiki/%E5%9C%A8%E7%94%9F%E4%BA%A7%E7%8E%AF%E5%A2%83%E4%B8%AD%E4%BD%BF%E7%94%A8-Sentinel
- https://github.com/alibaba/Sentinel/wiki/Sentinel-%E6%8E%A7%E5%88%B6%E5%8F%B0%EF%BC%88%E9%9B%86%E7%BE%A4%E6%B5%81%E6%8E%A7%E7%AE%A1%E7%90%86%EF%BC%89#%E8%A7%84%E5%88%99%E9%85%8D%E7%BD%AE
- https://blog.csdn.net/qq_42714869/article/details/94553378