使用最新的Spring Boot2.0.3和 Spring Cloud F 系列進(jìn)行微服務(wù)架構(gòu)開發(fā)硝枉，在做壓測(cè)的時(shí)候遇到了很多問題抚笔，經(jīng)過一日一夜的源碼和 google苟翻，終于弄出一套方案衰倦。

關(guān)鍵字：com.netflix.hystrix.exception.HystrixRuntimeException花鹅； timeout； could not be queued for execution

1交掏、替換 tomcat

首先妆偏，把 tomcat 換成 undertow，這個(gè)性能在 Jmeter 的壓測(cè)下盅弛，undertow 比 tomcat 高一倍

第一步钱骂，pom 修改

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-undertow</artifactId>
        </dependency>

第二步，配置

server: 
  undertow: 
    max-http-post-size: 0 
# 設(shè)置IO線程數(shù), 它主要執(zhí)行非阻塞的任務(wù),它們會(huì)負(fù)責(zé)多個(gè)連接, 默認(rèn)設(shè)置每個(gè)CPU核心一個(gè)線程,數(shù)量和CPU 內(nèi)核數(shù)目一樣即可
    io-threads: 4
# 阻塞任務(wù)線程池, 當(dāng)執(zhí)行類似servlet請(qǐng)求阻塞操作, undertow會(huì)從這個(gè)線程池中取得線程,它的值設(shè)置取決于系統(tǒng)的負(fù)載  io-threads*8
    worker-threads: 32
# 以下的配置會(huì)影響buffer,這些buffer會(huì)用于服務(wù)器連接的IO操作,有點(diǎn)類似netty的池化內(nèi)存管理
# 每塊buffer的空間大小,越小的空間被利用越充分
    buffer-size: 1024
# 每個(gè)區(qū)分配的buffer數(shù)量 , 所以pool的大小是buffer-size * buffers-per-region
#   buffers-per-region: 1024 # 這個(gè)參數(shù)不需要寫了
# 是否分配的直接內(nèi)存
    direct-buffers: true

2熊尉、替換 HTTPClient

其次把普通的 HTTPURLConnection 替換為使用 HTTPClient
第一步 pom 增加對(duì)應(yīng)的包

<dependency>
             <groupId>io.github.openfeign</groupId>
             <artifactId>feign-httpclient</artifactId>
          </dependency>

第二部罐柳，在 application.yml或者 bootstrap.yml 里面配置

# feign配置
feign:
  hystrix:
    # 在feign中開啟hystrix功能，默認(rèn)情況下feign不開啟hystrix功能
    enabled: true
  ## 配置httpclient線程池
  httpclient:
    enabled: true
  okhttp: 
    enabled: false

第三步狰住，配置 HTTPClient Bean

import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;

import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.impl.client.DefaultConnectionKeepAliveStrategy;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class HttpPool {

    @Bean
    public HttpClient httpClient(){
        System.out.println("===== Apache httpclient 初始化連接池開始===" );
        // 生成默認(rèn)請(qǐng)求配置
        RequestConfig.Builder requestConfigBuilder = RequestConfig.custom();
        // 超時(shí)時(shí)間
        requestConfigBuilder.setSocketTimeout(5 * 1000);
        // 連接時(shí)間
        requestConfigBuilder.setConnectTimeout(5 * 1000);
        RequestConfig defaultRequestConfig = requestConfigBuilder.build();
        // 連接池配置
        // 長(zhǎng)連接保持30秒
        final PoolingHttpClientConnectionManager pollingConnectionManager = new PoolingHttpClientConnectionManager(30, TimeUnit.MILLISECONDS);
        // 總連接數(shù)
        pollingConnectionManager.setMaxTotal(1000);
        // 同路由的并發(fā)數(shù)
        pollingConnectionManager.setDefaultMaxPerRoute(100);

        // httpclient 配置
        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
        // 保持長(zhǎng)連接配置墅垮，需要在頭添加Keep-Alive
        httpClientBuilder.setKeepAliveStrategy(new DefaultConnectionKeepAliveStrategy());
        httpClientBuilder.setConnectionManager(pollingConnectionManager);
        httpClientBuilder.setDefaultRequestConfig(defaultRequestConfig);
        HttpClient client = httpClientBuilder.build();

        // 啟動(dòng)定時(shí)器从媚，定時(shí)回收過期的連接
        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("=====closeIdleConnections===");
                pollingConnectionManager.closeExpiredConnections();
                pollingConnectionManager.closeIdleConnections(5, TimeUnit.SECONDS);
            }
        }, 10 * 1000, 5 * 1000);
        System.out.println("===== Apache httpclient 初始化連接池完畢===");

        return client;
    }


}

3泞坦、配置 Hystrix

第一步刻帚，還是導(dǎo)入包

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

第二步，配置

# 配置hystrix的參數(shù)
hystrix:
  threadpool:
    # default: 默認(rèn)參數(shù)创南，作用的所有的hystrix的客戶端,如果需要對(duì)某個(gè)具體的接口伦忠，可以寫接口+方法名稱
    default:
      coreSize: 500
  command:
    default:
      fallback:
        # 是否開啟回退方法
        enabled: true
      execution:
        isolation:
          thread:
            timeoutInMilliseconds: 30000 #缺省為1000

4、壓測(cè)吧