前言

上一篇文章Spring Cloud进阶之路 | 十五：服务网关集成断路器（zuul + hystrix）中，介绍了服务网关如何集成断路器。但是，与之前其它服务集成断路器一样，我们始终无法直观的看到断路器相关信息。因此，需要集成断路器监控组件，来以图形化的方式友好地展示断路器信息。

准备工作

复用上一篇文章Spring Cloud进阶之路 | 十五：服务网关集成断路器（zuul + hystrix）中的全部工程：xmall-auth、xmall-product、xmall-zuul。

改造zuul

添加依赖

如同其它服务添加断路器监控组件一样，添加spring-cloud-starter-netflix-hystrix-dashboard依赖。

<?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>

    <parent>
        <groupId>com.luas.cloud</groupId>
        <artifactId>java-boot-parent-2.1</artifactId>
        <version>1.0.0-SNAPSHOT</version>
        <relativePath>../../java-boot-parent-2.1</relativePath>
    </parent>

    <groupId>com.luas.xmall</groupId>
    <artifactId>xmall-zuul</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <name>xmall-zuul</name>
    <description>网关服务</description>

    <properties>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-oauth2</artifactId>
        </dependency>

        <!-- nacos cloud -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</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-netflix-hystrix</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

开启断路器监控

启动类新增@EnableHystrixDashboard注解。

package com.luas.xmall.gateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
import org.springframework.cloud.openfeign.EnableFeignClients;

@EnableHystrixDashboard
@EnableFeignClients
@EnableCircuitBreaker
@EnableZuulProxy
@SpringBootApplication
public class XmallZuulApplication {

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

}

配置

修改zuul hystrix默认隔离策略为thread。

zuul:
  prefix: /gateway
  sensitive-headers:
  routes:
    auth:
      path: /auth/**
      service-id: xmall-auth
      strip-prefix: true
    product:
      path: /product/**
      service-id: xmall-product
      strip-prefix: true
  ribbon-isolation-strategy: thread

放开hystrix.stream端点

management:
  endpoints:
    web:
      exposure:
        include: '*'

完整的application.yml文件如下。

server:
  port: 5566

zuul:
  prefix: /gateway
  sensitive-headers:
  routes:
    auth:
      path: /auth/**
      service-id: xmall-auth
      strip-prefix: true
    product:
      path: /product/**
      service-id: xmall-product
      strip-prefix: true
  ribbon-isolation-strategy: thread

security:
  oauth2:
    resource:
      user-info-uri: http://localhost:7777/oauth/user
      prefer-token-info: false

feign:
  hystrix:
    enabled: true

management:
  endpoints:
    web:
      exposure:
        include: '*'

资源服务器安全策略

修改资源服务器安全策略，放开与hystrix监控相关的端点。

package com.luas.xmall.gateway.configuration;

import com.luas.xmall.gateway.oauth2.endpoint.AuthorizationServerEndpoints;

import org.apache.commons.lang3.StringUtils;

import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.oauth2.config.annotation.web.configuration.EnableResourceServer;
import org.springframework.security.oauth2.config.annotation.web.configuration.ResourceServerConfigurerAdapter;

@Configuration
@EnableResourceServer
public class ResourceServerConfiguration extends ResourceServerConfigurerAdapter {

    private String prefixAntPattern;

    public ResourceServerConfiguration(ZuulProperties zuulProperties) {
        this.prefixAntPattern = StringUtils.isBlank(zuulProperties.getPrefix()) ? "/*" : zuulProperties.getPrefix() + "/*";
    }

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http
                .authorizeRequests()
                .antMatchers(this.prefixAntPattern + AuthorizationServerEndpoints.TOKEN_ENDPOINT).permitAll()
                .antMatchers(this.prefixAntPattern + AuthorizationServerEndpoints.TOKEN_KEY_ENDPOINT).permitAll()
                .antMatchers(this.prefixAntPattern + AuthorizationServerEndpoints.CHECK_TOKEN_ENDPOINT).permitAll()
                .antMatchers("/favicon.ico").permitAll()
                .antMatchers("/proxy.stream").permitAll()
                .antMatchers("/hystrix.stream").permitAll()
                .antMatchers("/actuator/**").permitAll()
                .antMatchers("/webjars/**").permitAll()
                .antMatchers("/hystrix/**").permitAll()
                .anyRequest().authenticated()
        ;
    }
}

/favicon.ico、/proxy.stream、/hystrix.stream、/actuator/**、/hystrix/**、/webjars/**等端点，必须开放为公共端点，否则，断路器监控界面将不能正常展示，会被Spring Security拦截。

验证

依次启动xmall-product、xmall-auth、xmall-zuul工程，端口分别为8080、7777、5566。

申请授权。

访问http://localhost:5566/actuator/hystrix.stream，不出所料，肯定是一直ping。

与此同时，访问hystrix监控界面肯定是loading状态。下面就访问相关接口，产生监控数据。

使用上一步申请的授权，访问sku接口http://localhost:5566/gateway/product/sku/1122。

此时，hystrix.stream已有数据返回。

与此同时，hystrix监控页面图形化展示已正常。

其中，RibbonCommand为线程池名称，此名称为zuul默认的hystrix创建，正对应了之前配置项中将zuul hystrix隔离策略修改为thread。至于xmall-product则是默认的hystrix创建的线程池，通过feign客户端远程调用产生数据。

问题

如果网关工程中，没有远程调用逻辑，如rest + ribbon、或者feign，此时，hystrix监控界面不展示线程池信息，一直是loading状态，如图。

此种情况的原因为zuul hystrix默认隔离策略为semaphore，而不是thread。

如果网关工程中，存在远程调用逻辑，无论rest + ribbon、或者feign，出现hystrix监控界面不展示情况，除了上述不存在远程调用逻辑的原因之外，还有可能是hystrix默认隔离策略的问题。hystrix默认隔离策略为thread，如果配置为semaphore，则远程调用部分的线程池则不会创建。

hystrix:
  command:
    default:
      execution:
        isolation:
          strategy: THREAD

也可单独为某服务配置隔离策略。

hystrix:
  command:
    default:
      execution:
        isolation:
          strategy: THREAD
    xmall-product:
      execution:
        isolation:
          strategy: SEMAPHORE

如下图情况，原因为zuul hystrix默认隔离策略未配置为thread，而hystrix默认隔离策略为thread。