服务器达到pm.max_children设置(280)，请考虑提高它

Question

由于到达pm.max_children，每隔几天PHP进程就会崩溃，我必须手动启动它来创建站点。

服务器配置：

Total Memory: 7986M 
CPU: 2 Core
1 PHP Process Taking: 22M

PHP配置：

pm = dynamic
pm.max_children = 280
pm.start_servers = 15
pm.min_spare_servers = 15
pm.max_spare_servers = 35
pm.max_requests = 1000

检查PHP日志，发现以下错误。

[02-Aug-2017 23:23:54] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 8 children, there are 10 idle, and 41 total children
[02-Aug-2017 23:24:04] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 8 children, there are 0 idle, and 55 total children
[02-Aug-2017 23:24:05] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 16 children, there are 0 idle, and 63 total children
[02-Aug-2017 23:24:06] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 78 total children
[02-Aug-2017 23:24:07] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 93 total children
[02-Aug-2017 23:24:08] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 108 total children
[02-Aug-2017 23:24:09] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 123 total children
[02-Aug-2017 23:24:10] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 138 total children
[02-Aug-2017 23:24:11] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 153 total children
[02-Aug-2017 23:24:12] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 168 total children
[02-Aug-2017 23:24:13] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 183 total children
[02-Aug-2017 23:24:14] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 198 total children
[02-Aug-2017 23:24:15] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 213 total children
[02-Aug-2017 23:24:16] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 228 total children
[02-Aug-2017 23:24:17] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 243 total children
[02-Aug-2017 23:24:18] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 258 total children
[02-Aug-2017 23:24:19] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 273 total children
[02-Aug-2017 23:24:20] WARNING: [pool www] server reached pm.max_children setting (280), consider raising it

我可以有人建议为PHP的最佳优化配置，这可以帮助避免崩溃。

以下这句话的意思是：

[02-Aug-2017 23:23:54] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 8 children, there are 10 idle, and 41 total children

Answer 1

这里有一个计算正确数字的建议：

https://myshell.co.uk/blog/2012/07/adjusting-child-processes-for-php-fpm-nginx/

以下命令将帮助我们确定每个子进程(PHP)所使用的内存：

ps -ylC php-fpm --sort:rss

然后，获取服务器可用的RAM并计算：

pm.max_children = Total RAM dedicated to the web server / Max child process size

另见：

php5-fpm:服务器到达pm.max_孩子们

Answer 2

首先，你应该找出你真正需要多少个fpm孩子。在池配置中启用慢速日志，或者使用外部服务(如NewRelic )查找代码中的慢点和弱点。可能是MySQL连接或PHP中存在瓶颈。你得到了“似乎很忙”，因为他们正忙着等待来自DataBase或其他方面的答复。无缘无故地增加pm.max_children是一种糟糕的做法。