PHP-FPM Sub-process count control

Related parameters:

PM = XXX: How to control child processes, options are static and dynamic, OnDemand (ondemand: No child processes are created when starting, and are created when new requests are made).

Pm.max_children = XXX:

The number of PHP-FPM child processes created when PM = static;

The maximum number of PHP-FPM child processes that are created when pm = Dynamic or OnDemand.

Pm.start_servers = xxx:dynamic mode, the system will start the "Pm.start_servers" php-fpm sub-process when PHP-FPM is running.

Pm.min_spare_servers = the number of minimum idle processes in xxx:dynamic mode. If the idle process is less than this value, the corresponding process is created.

pm.max_spare_servers = number of maximum idle processes in xxx:dynamic mode. If the idle process is larger than this value, the extra idle process is killed.

The system adjusts the number of PHP-FPM processes dynamically between "pm.min_spare_servers" and "pm.max_spare_servers" based on demand.

Values for the relevant parameters:

    Use the PS command to view the memory size of each PHP-FPM process: After a period of running, each process consumes about 20m-30m.

# ps -ylc php-fpm --sort:rsss   uid   pid  ppid   c pri  ni   rss    sz wchan  tty           time cmds     0  29355     1  0  80   0  4352  51301 ep_pol ?        00:15:03 php-fpms  2002  12865 29355  0  80   0 19296 54206 skb_re ?         00:58:51 php-fpms  2002 29365 29355   0  80   0 19780 54335 skb_re ?         05:44:56 php-fpmS  2002 29359 29355  0   80   0&Nbsp;21280 54650 skb_re ?        05:44:51 php-fpms   2002 29357 29355  0  80   0 21676 55289  skb_re ?        05:44:18 php-fpms  2002  29358 29355  0  80   0 22716 55033 skb_re ?         05:43:25 php-fpms  2002 29362 29355   0  80   0 26576 56073 skb_re ?         05:43:56 php-fpmS  2002 29360 29355  0   80   0 26864 56144 skb_re ?         05:44:18 php-fpmS  2002 29361 29355  0  80    0 26888 56165 skb_re ?        05:43:32 php-fpms  2002  29356 29355  0  80   0 26896 56109 skb_re ?         05:44:23 php-fpmS  2002 29370 29355   0  80   0 27196 56146 skb_re ?         05:43:10 php-fpmS  2002 29371 29355  0   80   0 27240 56160 skb_re ?         05:44:10 php-fpms  2002 29363 29355  0  80   0  27460 56227 skb_re ?        05:44:30  php-fpms  2002 29373 29355  0  80   0 27636  56742 skb_re ?        05:43:27 php-fpms  2002 29366 29355   0  80   0 28436 56427 skb_re ?         05:42:49 php-fpms  2002 29374 29355  0  80    0 28636 56494 skb_re ?         05:44:40 php-fpms  2002 29368 29355  0  80   0  28844 56999 skb_re ?        05:44:05  php-fpms  2002 29375 29355  0  80   0 29972  56842 skb_re ?        05:43:18 php-fpms  2002  29367 29355  0  80   0 30048 56800 skb_re ?         05:43:31 php-fpms  2002 29364 29355  0  80    0 35872 58251 skb_re ?        05:44:25  php-fpms  2002 29372 29355  0  80   0 42840  60428 skb_re ?        05:44:19 php-fpm

PM which to use, according to the server hardware configuration to decide it. Process generation and destruction will bring a certain amount of resource overhead, so considering the stability, the choice of static more appropriate. The use of dynamic can end redundant processes and free up memory.

Pm.max_children value of the set, generally take "memory/20m". The memory here is not included in the memory that other processes occupy.

Pm.start_servers value =min_spare_servers + (max_spare_servers-min_spare_servers)/2

For example, 512M VPS, if allocated to PHP-FPM maximum 250M, the recommended pm.max_spare_servers set to 250/30, about 8. As for Pm.min_spare_servers, it is recommended that you set the load on the server, for example, if the server is just deploying a PHP environment, the more appropriate values are between 2~5.

In addition: Pm.max_requests = 500, sets the number of requests for the service before each child process restarts. is useful for third-party modules that may have a memory leak. If set to ' 0 ', the request is always accepted.

PHP-FPM Sub-process count control