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Spring Cloud Alibaba系列(四)微服务网关Gateway及在网关上用sentinel进行限流熔断

发布时间 2023-03-25 18:51:57作者: 我的笔记本

Spring Cloud Gateway是基于Netty，使用Reactor连接方式的，采用非阻塞方式，相比zuul支持更高的并发，且zuul已经停止维护，我们应该使用Gateway来构建微服务应用。

一. 使用nacos实现负载均衡

实际业务场景中，Gateway会和Nacos配合使用来做到负载均衡，nacos的搭建请参考文章 https://www.cnblogs.com/fxhui/p/17248503.html

创建一个名为mygateway的项目，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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>mygateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mygateway</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.6.11</spring-boot.version>
        <spring-cloud.version>2021.0.5</spring-cloud.version>
        <spring-cloud-alibaba.version>2021.0.4.0</spring-cloud-alibaba.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </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>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
                <configuration>
                    <mainClass>com.example.mygateway.MygatewayApplication</mainClass>
                    <skip>true</skip>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

启动类新增注解@EnableDiscoveryClient

package com.example.mygateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@EnableDiscoveryClient
@SpringBootApplication
public class MygatewayApplication {

    public static void main(String[] args) {
        SpringApplication.run(MygatewayApplication.class, args);
    }

}

resource里添加application.yml配置文件，分别新增的gateway路由配置和nacos注册中心配置，lb是loadbalance简称，网关接收到/hello后会将请求转发到lb://serviceProvider上，以负载均衡方式访问服务serviceProvider

server:
  port: 7079
spring:
  cloud:
    gateway:
      routes:
        - id: loadbalance_route
          uri: lb://serviceProvider
          predicates:
            - Path=/hello
    nacos:
      discovery:
        server-addr: 127.0.0.1:8867,127.0.0.1:8869
  application:
    name: mygateway

 我们通过访问网关http://localhost:7079/hello就可以访问到serviceProvider的接口

 

二. 使用sentinel实现限流熔断防护

限流防护的使用方法在前文中已经给出，具体见这篇文章https://www.cnblogs.com/fxhui/p/17238253.html

之前只是在方法上实现，本文讲讲如何在网关层通过路由实现防护

 在pom.xml新增sentinel依赖包，整体文件如下：

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>mygateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mygateway</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.6.11</spring-boot.version>
        <spring-cloud.version>2021.0.5</spring-cloud.version>
        <spring-cloud-alibaba.version>2021.0.4.0</spring-cloud-alibaba.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </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>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
                <configuration>
                    <mainClass>com.example.mygateway.MygatewayApplication</mainClass>
                    <skip>true</skip>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

在application.yml中添加sentinel配置，整体文件如下：

server:
  port: 7079
spring:
  cloud:
    sentinel:
      transport:
        # 与sentinel控制台交互的端口
        port: 9000
        # sentinel控制台的工作地址和端口
        dashboard: localhost:8090
    gateway:
      routes:
        - id: loadbalance_route
          uri: lb://serviceProvider
          predicates:
            - Path=/hello
    nacos:
      discovery:
        server-addr: 127.0.0.1:8867,127.0.0.1:8869
  application:
    name: mygateway

启动服务后打开sentinel控制台，访问网关接口http://localhost:7079/hello

 

 打开mygateway下拉，点击簇点链路

 

 点击资源/hello的流控按钮，输入单机阈值

 

 访问网关的接口http://localhost:7079/hello，不停刷新，发现经常出现以下错误，资源已经被控制为单机阈值1了