【发布时间】：2019-04-02 12:33:25
【问题描述】：
我需要创建一个每秒支持 40 个并发用户的产品（我是处理并发的新手）
为了实现这一点，我尝试开发了一个 hello world spring-boot 项目。 即，
弹簧启动 (1.5.9)
码头 9.4.15
具有获取端点的休息控制器
代码如下：
@GetMapping
public String index() {
return "Greetings from Spring Boot!";
}
在 Gen10 DL360 机器上运行的应用
然后我尝试使用 apachebench 进行基准测试
75 个并发用户：
ab -t 120 -n 1000000 -c 75 http://10.93.243.87:9000/home/
Server Software:
Server Hostname: 10.93.243.87
Server Port: 9000
Document Path: /home/
Document Length: 27 bytes
Concurrency Level: 75
Time taken for tests: 37.184 seconds
Complete requests: 1000000
Failed requests: 0
Write errors: 0
Total transferred: 143000000 bytes
HTML transferred: 27000000 bytes
Requests per second: 26893.28 [#/sec] (mean)
Time per request: 2.789 [ms] (mean)
Time per request: 0.037 [ms] (mean, across all concurrent requests)
Transfer rate: 3755.61 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 1 23.5 0 3006
Processing: 0 2 7.8 1 404
Waiting: 0 2 7.8 1 404
Total: 0 3 24.9 2 3007
100 个并发用户：
ab -t 120 -n 1000000 -c 100 http://10.93.243.87:9000/home/
Server Software:
Server Hostname: 10.93.243.87
Server Port: 9000
Document Path: /home/
Document Length: 27 bytes
Concurrency Level: 100
Time taken for tests: 36.708 seconds
Complete requests: 1000000
Failed requests: 0
Write errors: 0
Total transferred: 143000000 bytes
HTML transferred: 27000000 bytes
Requests per second: 27241.77 [#/sec] (mean)
Time per request: 3.671 [ms] (mean)
Time per request: 0.037 [ms] (mean, across all concurrent requests)
Transfer rate: 3804.27 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 2 35.7 1 3007
Processing: 0 2 9.4 1 405
Waiting: 0 2 9.4 1 405
Total: 0 4 37.0 2 3009
500 个并发用户：
ab -t 120 -n 1000000 -c 500 http://10.93.243.87:9000/home/
Server Software:
Server Hostname: 10.93.243.87
Server Port: 9000
Document Path: /home/
Document Length: 27 bytes
Concurrency Level: 500
Time taken for tests: 36.222 seconds
Complete requests: 1000000
Failed requests: 0
Write errors: 0
Total transferred: 143000000 bytes
HTML transferred: 27000000 bytes
Requests per second: 27607.83 [#/sec] (mean)
Time per request: 18.111 [ms] (mean)
Time per request: 0.036 [ms] (mean, across all concurrent requests)
Transfer rate: 3855.39 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 14 126.2 1 7015
Processing: 0 4 22.3 1 811
Waiting: 0 3 22.3 1 810
Total: 0 18 129.2 2 7018
1000 个并发用户：
ab -t 120 -n 1000000 -c 1000 http://10.93.243.87:9000/home/
Server Software:
Server Hostname: 10.93.243.87
Server Port: 9000
Document Path: /home/
Document Length: 27 bytes
Concurrency Level: 1000
Time taken for tests: 36.534 seconds
Complete requests: 1000000
Failed requests: 0
Write errors: 0
Total transferred: 143000000 bytes
HTML transferred: 27000000 bytes
Requests per second: 27372.09 [#/sec] (mean)
Time per request: 36.534 [ms] (mean)
Time per request: 0.037 [ms] (mean, across all concurrent requests)
Transfer rate: 3822.47 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 30 190.8 1 7015
Processing: 0 6 31.4 2 1613
Waiting: 0 5 31.4 1 1613
Total: 0 36 195.5 2 7018
从上面的测试运行中，我自己在 75 个用户的情况下达到了每秒约 27K，但它看起来增加了用户也增加了延迟。此外，我们可以清楚地注意到连接时间正在增加。
我要求我的应用程序支持 40k 并发用户（假设所有人都使用自己单独的浏览器）并且请求应在 250 毫秒内完成。
请帮帮我
【问题讨论】：
-
您是否已经检测过您的代码？看看你大部分时间都花在了哪里？你的瓶颈在哪里？ （cpu？内存？gc？磁盘？网络？）你的服务器配置是怎样的？ （线程池？连接器？等）您针对高负载执行了哪些典型的操作系统调整？ - 还要非常小心你的choice of benchmark。
-
是的，我已经通过应用eclipse.org/jetty/documentation/current/high-load.html 对我的操作系统进行了调整
-
投入大量时间后，发现如下： 1. 在运行应用程序的虚拟机中启用了超线程。即，8 个物理核心在超线程后转换为 8 个物理核心 + 8 个逻辑核心 = 16 个核心。 2. 在负载测试期间，我可以看到 java 进程只使用了 800% 到 900% 的 CPU，即 java 进程使用了 8 到 9 个内核，不超过这个。并且整个系统 cpu 百分比高达 40% 到 50% 现在的问题是，为什么 java 直到 cpu 周期的 1500% 到 1600% 才占用？
标签： spring-boot concurrency embedded-jetty apachebench c10k