协程的优势
协程模式与常驻内存模式(同步)/传统模式相比：
常驻模式/传统模式都属于同步阻塞编程，由于同一个进程不能并行处理请求，所以为了提高并发，只能开启更多的进程，通常超过 100 甚至更多，每个进程都有基础的内存消耗，加起来就很多了，而且受限于 Linux 总进程数限制，并发总数无法突破，加上进程非常多之后，CPU 需要更多的线程切换，浪费了很多性能，当然相比 FPM 的传统模式每次都需从头开始，常驻模式还是要好非常多的，但是协程显然更加优秀。
协程模式的执行方式：
协程模式中一个进程可以同时执行 N 个请求，但同一时刻只执行其中的某一个请求，也就是说，当执行到 MySQL/Redis 这些客户端时，由于需要等待客户端响应，常驻模式/传统模式通常是在傻傻的等待响应，而协程这个时候会挂起当前协程，切换到其他协程中去处理其他请求，所以协程能同时处理 N 个请求，每增加一个请求只需增加一些内存消耗，相比增加一个进程的内存消耗，显然是少太多的，由于协程能并行处理，所以通常只需配置于 CPU 数量 1～2 倍左右的进程数即可，更少的进程带来更少的 CPU 线程切换，又减少很多性能损耗。
开始测试
MixPHP 是一个基于 Swoole 的FPM、常驻内存、协程三模 PHP 高性能框架，由于该框架同时具备常驻内存模式、协程模式，所以能很方便的测试结果。
测试环境：
docker 容器，限制只能使用 1 CPU。
其他参数如下：
Server Name: mix-httpd Framework Version: 1.1.0-RC PHP Version: 7.2.9 Swoole Version: 4.1.0 Listen Addr: 127.0.0.1 Listen Port: 9501
代码：
模拟常用的 HTTP 开发需求，执行三个 SQL 请求。
// 默认动作public function actionIndex(){
PDO::createCommand("select * from `test` where id = 1")->queryOne();
PDO::createCommand("select * from `test` where id = 2")->queryOne(); return PDO::createCommand("select * from `test` limit 5")->queryAll();
}测试结果
常驻内存模式(同步)：
| 进程数 | 并发数 | RPS |
|---|---|---|
| 8 | 100 | 838.65 |
| 8 | 300 | 683.78 |
| 8 | 500 | 688.56 |
| 50 | 100 | 770.69 |
| 50 | 300 | 304.90 |
| 50 | 300 | 378.95 |
协程模式：
| 进程数 | 并发数 | RPS |
|---|---|---|
| 8 | 100 | 834.12 |
| 8 | 300 | 837.50 |
| 8 | 500 | 824.14 |
协程在本次测试中并没有像之前的传统 Apache/FPM 模式与常驻内存模式(同步)的测试一样展现出巨大的性能提升，说明：
在少量能快速响应的 SQL 请求中，协程的提升并不明显，应该要在响应时间更大时，才能感受到协程优势。
常驻内存模式的进程数配置过多，并发性能反而会降低，该问题同样适用于传统 Apache/FPM 模式。
常驻内存模式(同步)详细测试
首先 8 个 Worker 进程，并发 100 测试，RPS 为 838.65。
C:\Users\EDZ>ab -n 10000 -c 100 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 100Time taken for tests: 11.924 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 838.65 [#/sec] (mean)Time per request: 119.239 [ms] (mean) Time per request: 1.192 [ms] (mean, across all concurrent requests) Transfer rate: 217.85 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 0 0.2 0 4Processing: 20 118 18.3 118 195Waiting: 19 118 18.4 118 195Total: 20 118 18.4 119 195Percentage of the requests served within a certain time (ms) 50% 119 66% 126 75% 130 80% 133 90% 141 95% 147 98% 155 99% 161 100% 195 (longest request)
然后使用 8 个 Worker 进程，并发 300 测试，RPS 为 683.78。
C:\Users\EDZ>ab -n 10000 -c 300 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 300Time taken for tests: 14.624 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 683.78 [#/sec] (mean)Time per request: 438.735 [ms] (mean) Time per request: 1.462 [ms] (mean, across all concurrent requests) Transfer rate: 177.62 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 0 30.0 0 3000Processing: 62 432 493.4 354 3457Waiting: 54 431 488.1 354 3455Total: 62 433 494.1 354 3457Percentage of the requests served within a certain time (ms) 50% 354 66% 373 75% 385 80% 392 90% 411 95% 432 98% 3170 99% 3266 100% 3457 (longest request)
然后使用 8 个 Worker 进程，并发 500 测试，RPS 为 688.56。
C:\Users\EDZ>ab -n 10000 -c 500 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 500Time taken for tests: 14.523 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 688.56 [#/sec] (mean)Time per request: 726.150 [ms] (mean) Time per request: 1.452 [ms] (mean, across all concurrent requests) Transfer rate: 178.87 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 0 30.0 0 3000Processing: 102 707 618.4 596 3632Waiting: 89 703 605.6 595 3629Total: 102 707 618.9 596 3633Percentage of the requests served within a certain time (ms) 50% 596 66% 620 75% 635 80% 645 90% 679 95% 3125 98% 3401 99% 3495 100% 3633 (longest request)
现在调整为 50 进程，100 并发测试，RPS 为 770.69。
进程的增加并没有带来并发量的提升。
C:\Users\EDZ>ab -n 10000 -c 100 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 100Time taken for tests: 12.975 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 770.69 [#/sec] (mean)Time per request: 129.754 [ms] (mean) Time per request: 1.298 [ms] (mean, across all concurrent requests) Transfer rate: 200.20 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 1 42.4 0 3000Processing: 10 128 499.8 56 7137Waiting: 10 127 495.8 55 7137Total: 11 129 503.3 56 7137Percentage of the requests served within a certain time (ms) 50% 56 66% 72 75% 86 80% 97 90% 133 95% 179 98% 312 99% 3052 100% 7137 (longest request)
50 进程，300 并发测试，RPS 为 304.90。
对比 8 个进程时的结果，并发量降低非常明显，看来进程数过多并不能提升性能，反而会降低性能。
C:\Users\EDZ>ab -n 10000 -c 300 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 300Time taken for tests: 32.798 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 304.90 [#/sec] (mean)Time per request: 983.942 [ms] (mean) Time per request: 3.280 [ms] (mean, across all concurrent requests) Transfer rate: 79.20 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 3 90.0 0 3001Processing: 25 976 1339.8 189 3694Waiting: 23 954 1316.5 188 3691Total: 25 979 1341.0 189 3694Percentage of the requests served within a certain time (ms) 50% 189 66% 289 75% 3094 80% 3113 90% 3184 95% 3249 98% 3315 99% 3375 100% 3694 (longest request)
50 进程，500 并发测试，RPS 为 378.95。
C:\Users\EDZ>ab -n 10000 -c 500 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 500Time taken for tests: 26.389 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 378.95 [#/sec] (mean)Time per request: 1319.431 [ms] (mean) Time per request: 2.639 [ms] (mean, across all concurrent requests) Transfer rate: 98.44 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 2 79.4 0 3001Processing: 64 1306 1434.7 341 3962Waiting: 17 1224 1391.4 321 3959Total: 65 1308 1435.2 342 3963Percentage of the requests served within a certain time (ms) 50% 342 66% 3142 75% 3168 80% 3195 90% 3292 95% 3374 98% 3467 99% 3516 100% 3963 (longest request)
协程模式详细测试
首先 8 个 Worker 进程，并发 100 测试，RPS 为 834.12。
C:\Users\EDZ>ab -n 10000 -c 100 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 100Time taken for tests: 11.989 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 834.12 [#/sec] (mean)Time per request: 119.886 [ms] (mean) Time per request: 1.199 [ms] (mean, across all concurrent requests) Transfer rate: 216.68 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 0 0.3 0 4Processing: 84 119 9.8 122 165Waiting: 84 119 9.8 122 164Total: 84 119 9.8 123 165Percentage of the requests served within a certain time (ms) 50% 123 66% 124 75% 125 80% 125 90% 126 95% 128 98% 131 99% 137 100% 165 (longest request)
然后使用 8 个 Worker 进程，并发 300 测试，RPS 为 837.50。
C:\Users\EDZ>ab -n 10000 -c 300 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 300Time taken for tests: 11.940 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 837.50 [#/sec] (mean)Time per request: 358.207 [ms] (mean) Time per request: 1.194 [ms] (mean, across all concurrent requests) Transfer rate: 217.55 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 1 42.4 0 3001Processing: 86 354 1043.0 161 7172Waiting: 86 344 1011.9 160 7172Total: 86 355 1044.5 161 7172Percentage of the requests served within a certain time (ms) 50% 161 66% 182 75% 199 80% 212 90% 251 95% 302 98% 6103 99% 6135 100% 7172 (longest request)
然后使用 8 个 Worker 进程，并发 500 测试，RPS 为 824.14。
C:\Users\EDZ>ab -n 10000 -c 500 http://www.a.com/This is ApacheBench, Version 2.3 <$Revision: 1757674 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.a.com (be patient) Completed 1000 requests Completed 2000 requests Completed 3000 requests Completed 4000 requests Completed 5000 requests Completed 6000 requests Completed 7000 requests Completed 8000 requests Completed 9000 requests Completed 10000 requests Finished 10000 requests Server Software: nginx/1.13.9Server Hostname: www.a.com Server Port: 80Document Path: / Document Length: 101 bytes Concurrency Level: 500Time taken for tests: 12.134 seconds Complete requests: 10000Failed requests: 0Total transferred: 2660000 bytes HTML transferred: 1010000 bytes Requests per second: 824.14 [#/sec] (mean)Time per request: 606.690 [ms] (mean) Time per request: 1.213 [ms] (mean, across all concurrent requests) Transfer rate: 214.08 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 0 0.3 0 4Processing: 92 332 585.3 198 6931Waiting: 91 331 585.5 196 6931Total: 92 332 585.3 198 6931Percentage of the requests served within a certain time (ms) 50% 198 66% 242 75% 284 80% 334 90% 587 95% 932 98% 1216 99% 2390 100% 6931 (longest request)
作者：撸代码的乡下人
链接：https://www.jianshu.com/p/df1e1e823867