zuul集成Sentinel,完成对path映射的限流操作_Java教程

zuul集成Sentinel完成对path映射的限流

前面我们讲过了对单体应用的Sentinel限流，以及使用zookeeper对规则的持久化。通过前面的工作，我们可以完成单个实例的细粒度的限流、熔断操作。

譬如有一个服务User，在分布式环境下，开启了多个实例，那么每个实例都可以获得如每秒限制10个登录的限流功能。但是有些场景下，我们想要另外一种限流方式，譬如在网关zuul层，想限制对User服务的限流，而不去关心具体它有多少个实例。这时，就需要用到网关限流了。

Sentinel 1.6.0 引入了 Sentinel API Gateway Adapter Common 模块，包含网关限流的规则和自定义 API 的实体和管理逻辑：

GatewayFlowRule：网关限流规则，针对 API Gateway 的场景定制的限流规则，可以针对不同 route 或自定义的 API 分组进行限流，支持针对请求中的参数、Header、来源 IP 等进行定制化的限流。

ApiDefinition：用户自定义的 API 定义分组，可以看做是一些 URL 匹配的组合。比如我们可以定义一个 API 叫 my_api，请求 path 模式为 /foo/** 和 /baz/** 的都归到 my_api 这个 API 分组下面。

限流的时候可以针对这个自定义的 API 分组维度进行限流。

注意这个版本，1.6.0以后才有的。

zuul集成Sentinel,完成对path映射的限流操作

我们直接上代码，进入实战。新建一个SpringCloud项目，选中zuul。并在启动类上加上@EnableZuulProxy注解，代表这是一个zuul网关项目。

pom.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>sentinelzuul</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>sentinelzuul</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
        <sentinel.version>1.6.1</sentinel.version>
    </properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
        </dependency>
        <!--<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-zookeeper</artifactId>
        </dependency>-->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-zuul-adapter</artifactId>
            <version>${sentinel.version}</version>
        </dependency>
 
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-core</artifactId>
            <version>${sentinel.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-parameter-flow-control</artifactId>
            <version>${sentinel.version}</version>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
 
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
 
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>0.2.2.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

官方文档上写，只需要引入sentinel-zuul-adapter依赖，实测后发现，只引入这个的话，所依赖的Sentinel-core是1.5.2版本，会导致启动失败。所以我手工加入了其他几个依赖。

yml文件如下：

server:
  port: 9999
zuul:
  routes:
    one:
      path: /baoban/**
      url: http://localhost:8888/baoban/
spring:
  application:
    name: sentinelzuul

这里配了一个简单的routes映射。那是另外一个本地服务。

使用zuul的限流很简单，2个类即可

ZuulConfig.java

import com.alibaba.csp.sentinel.adapter.gateway.zuul.filters.SentinelZuulErrorFilter;
import com.alibaba.csp.sentinel.adapter.gateway.zuul.filters.SentinelZuulPostFilter;
import com.alibaba.csp.sentinel.adapter.gateway.zuul.filters.SentinelZuulPreFilter;
import com.netflix.zuul.ZuulFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
/**
 * @author wuweifeng wrote on 2019/7/3.
 */
@Configuration
public class ZuulConfig {
 
    @Bean
    public ZuulFilter sentinelZuulPreFilter() {
        return new SentinelZuulPreFilter(10000);
    }
 
    @Bean
    public ZuulFilter sentinelZuulPostFilter() {
        return new SentinelZuulPostFilter(1000);
    }
 
    @Bean
    public ZuulFilter sentinelZuulErrorFilter() {
        return new SentinelZuulErrorFilter(-1);
    }
}

package com.example.sentinelzuul.config; 
import com.alibaba.csp.sentinel.adapter.gateway.common.SentinelGatewayConstants;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiDefinition;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPathPredicateItem;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPredicateItem;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.GatewayApiDefinitionManager;
import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayParamFlowItem;
import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import org.springframework.context.annotation.Configuration; 
import javax.annotation.PostConstruct;
import java.util.HashSet;
import java.util.Set;
 
/**
 * @author wuweifeng wrote on 2019/7/3.
 */
@Configuration
public class GatewayRuleConfig {
    private static final int URL_MATCH_STRATEGY_EXACT = 0;
    private static final int URL_MATCH_STRATEGY_PREFIX = 1;
    private static final int URL_MATCH_STRATEGY_REGEX = 2;
 
    @PostConstruct
    public void doInit() {
        // Prepare some gateway rules and API definitions (only for demo).
        // It"s recommended to leverage dynamic data source or the Sentinel dashboard to push the rules.
        initCustomizedApis();
        initGatewayRules();
    }
 
    private void initCustomizedApis() {
        Set<ApiDefinition> definitions = new HashSet<>();
        ApiDefinition api1 = new ApiDefinition("baobao_api")
                .setPredicateItems(new HashSet<ApiPredicateItem>() {{
                    //add(new ApiPathPredicateItem().setPattern("/ahas"));
                    add(new ApiPathPredicateItem().setPattern("/baoban/**")
                            .setMatchStrategy(URL_MATCH_STRATEGY_PREFIX));
                }});
        //ApiDefinition api2 = new ApiDefinition("another_customized_api")
        //        .setPredicateItems(new HashSet<ApiPredicateItem>() {{
        //            add(new ApiPathPredicateItem().setPattern("/**")
        //                    .setMatchStrategy(URL_MATCH_STRATEGY_PREFIX));
        //        }});
        definitions.add(api1);
        //definitions.add(api2);
        GatewayApiDefinitionManager.loadApiDefinitions(definitions);
    }
 
    private void initGatewayRules() {
        Set<GatewayFlowRule> rules = new HashSet<>();
        rules.add(new GatewayFlowRule("baobao_api")
                .setResourceMode(SentinelGatewayConstants.RESOURCE_MODE_CUSTOM_API_NAME)
                .setCount(1)
                .setIntervalSec(1)
        );
        rules.add(new GatewayFlowRule("aliyun-product-route")
                .setCount(2)
                .setIntervalSec(2)
                //应对突发请求时额外允许的请求数目。
                .setBurst(2)
                .setParamItem(new GatewayParamFlowItem()
                        .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_CLIENT_IP)
                )
        );
        rules.add(new GatewayFlowRule("another-route-httpbin")
                .setCount(10)
                //统计时间窗口，单位是秒，默认是 1 秒。
                .setIntervalSec(1)
                //流量整形的控制效果，同限流规则的 controlBehavior 字段，目前支持快速失败和匀速排队两种模式，默认是快速失败。
                .setControlBehavior(RuleConstant.CONTROL_BEHAVIOR_RATE_LIMITER)
                //匀速排队模式下的最长排队时间，单位是毫秒，仅在匀速排队模式下生效。
                .setMaxQueueingTimeoutMs(600)
                //参数限流配置
                .setParamItem(new GatewayParamFlowItem()
                        .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_HEADER)
                        .setFieldName("X-Sentinel-Flag")
                )
        );
        rules.add(new GatewayFlowRule("another-route-httpbin")
                .setCount(1)
                .setIntervalSec(1)
                .setParamItem(new GatewayParamFlowItem()
                        .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_URL_PARAM)
                        .setFieldName("pa")
                )
        );
 
        rules.add(new GatewayFlowRule("some_customized_api")
                .setResourceMode(SentinelGatewayConstants.RESOURCE_MODE_CUSTOM_API_NAME)
                .setCount(5)
                .setIntervalSec(1)
                .setParamItem(new GatewayParamFlowItem()
                        .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_URL_PARAM)
                        .setFieldName("pn")
                )
        );
        GatewayRuleManager.loadRules(rules);
 
        //监听zookeeper，使用zookeeper的规则
        //ReadableDataSource<String, Set<GatewayFlowRule>> flowRuleDataSource = new ZookeeperDataSource<>(null, null,
        //        source -> JSON.parseObject(source, new TypeReference<Set<GatewayFlowRule>>() {
        //        }));
        //GatewayRuleManager.register2Property(flowRuleDataSource.getProperty());
    }
}

主要做的有2件事

1是配置一下APIDefinition，也就是给自己的映射规则起个名字。

2是配置Rule，和之前的配置rule差不多。创建一个rule的集合，设置rule规则，具体规则各字段在上面截图中有解释。

zuul集成Sentinel,完成对path映射的限流操作

这里我配了一个简单的一秒1个QPS的规则。最后用GatewayRuleManager去loadRules即可。

之后测试一下就发现规则已生效。频繁访问被限流的服务时，会报下面的异常。

zuul集成Sentinel,完成对path映射的限流操作

如果你想自定义这个熔断的返回值的话，可以加个类实现ZuulBlockFallbackProvider：

import com.alibaba.csp.sentinel.adapter.gateway.zuul.fallback.BlockResponse;
import com.alibaba.csp.sentinel.adapter.gateway.zuul.fallback.DefaultBlockFallbackProvider;
import com.alibaba.csp.sentinel.adapter.gateway.zuul.fallback.ZuulBlockFallbackProvider;
import com.alibaba.csp.sentinel.log.RecordLog;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
/**
 * @author wuweifeng wrote on 2019/7/3.
 */
public class MyBlockFallbackProvider implements ZuulBlockFallbackProvider {
 
    private Logger logger = LoggerFactory.getLogger(DefaultBlockFallbackProvider.class);
 
    // you can define route as service level
    @Override
    public String getRoute() {
        return "baobao_api";
    }
 
    @Override
    public BlockResponse fallbackResponse(String route, Throwable cause) {
        RecordLog.info(String.format("[Sentinel DefaultBlockFallbackProvider] Run fallback route: %s", route));
        if (cause instanceof BlockException) {
            return new BlockResponse(429, "the route is blocked", route);
        } else {
            return new BlockResponse(500, "System Error", route);
        }
    }
}

getRoute方法返回的就是上面定义的resouceName。然后注册一下就好了。

zuul集成Sentinel,完成对path映射的限流操作