Apache在Worker模式下的参数调整试验

我的配置如下：

<IfModule mpm_worker_module>

StartServers 2

MaxClients 150

MinSpareThreads 25

MaxSpareThreads 75

ThreadsPerChild 25

MaxRequestsPerChild 0

</IfModule>




ServerLimit没写就是16，它决定系统最多启动几个httpd进程。

ThreadLimit 没写默认是64，

ThreadsPerChild* ServerLimit=25*16=400，

400就是系统理论支持的最大并发。

MaxClients<ThreadsPerChild* ServerLimit，

MaxClients如果大于400将被限制在400.

400只是理论最大并发，实际并发就是MaxClients的值。

理论并发有什么用我不知道。



我做了如下试验：



第一次，ab -n 10000 -c 5000 http://192.168.1.101/

Time taken for tests: 127.952487 seconds


Requests per second: 78.15 [#/sec] (mean)

Time per request: 63976.242 [ms] (mean)

Time per request: 12.795 [ms] (mean, across all concurrent requests)

Transfer rate: 22.89 [Kbytes/sec] received




第二次，ab -n 10000 -c 400 http://192.168.1.101/

Time taken for tests: 138.340074 seconds


Requests per second: 72.29 [#/sec] (mean)

Time per request: 5533.603 [ms] (mean)

Time per request: 13.834 [ms] (mean, across all concurrent requests)

Transfer rate: 21.17 [Kbytes/sec] received




第三次，ab -n 10000 -c 150 http://192.168.1.101/

Time taken for tests: 6.727553 seconds


Requests per second: 1486.42 [#/sec] (mean)

Time per request: 100.913 [ms] (mean)

Time per request: 0.673 [ms] (mean, across all concurrent requests)

Transfer rate: 435.37 [Kbytes/sec] received




前提：访问apache的静态页面，本机。

结论是：并发如果大于MaxClients，服务器的效率会很低，如果并发等于小于MaxClients，10000个请求将迅速被处理完毕，效率很高。

疑问：400这个理论并发是不是就是用来限制MaxClients的啊？或许吧。