PHP-FPM start parameter and important configuration detailed

To agree on several directories

/USR/LOCAL/PHP/SBIN/PHP-FPM

/usr/local/php/etc/php-fpm.conf

/usr/local/php/etc/php.ini

First, the PHP-FPM start parameter

#测试php-fpm configuration

/usr/local/php/sbin/php-fpm-t

/usr/local/php/sbin/php-fpm-c/usr/local/php/etc/php.ini-y/ Usr/local/php/etc/php-fpm.conf-t

#启动php-fpm

/usr/local/php/sbin/php-fpm

/usr/local/php/sbin/ Php-fpm-c/usr/local/php/etc/php.ini-y/usr/local/php/etc/php-fpm.conf

#关闭php-fpm

kill-int ' cat/usr /local/php/var/run/php-fpm.pid '

#重启php-fpm

kill-usr2 ' cat/usr/local/php/var/run/php-fpm.pid '

Two, php-fpm.conf important parameter detailed explanation

Pid = run/php-fpm.pid #pid设置, default in the installation directory Var/run/php-fpm.pid, recommended open   error_log = log/ Php-fpm.log #错误日志, default Var/log/php-fpm.log   Log_level = notice in the installation directory .  available level is:  Alert (must be processed immediately),  error (Error condition),  warning (warning condition),  notice (general important information),  debug (debug information) .  default: 

Notice.   EMERGENCY_RESTART_THRESHOLD = 60 emergency_restart_interval = 60s #表示在emergency_ The number of php-cgi processes with SIGSEGV or sigbus errors within the set value of Restart_interval if more than  emergency_restart_threshold, PHP-FPM will gracefully restart.

These two options generally keep the default values.   process_control_timeout = 0 #设置子进程接受主进程复用信号的超时时间 .  available units:  s (sec),  m (min),  h (Hours),

  or  d (days)   default unit:  s (SEC) .  default value:  0.   Daemonize = yes #后台执行fpm, the default is yes, if you want to change to no for debugging. In FPM, you can use different settings to run multiple process pools.

  These settings can be set individually for each process pool.   listen = 127.0.0.1:9000 #fpm监听端口, that is, the address of PHP processing in Nginx, the general default value can be. Available formats are:  ' ip:port ',  ' Port ',  '/path/to/unix/socket ' .  each intoThe pool needs to be set.   Listen.backlog = -1 #backlog数, 1 means no limit, the operating system decides that this line is commented out. Backlog meaning reference: http://www.3gyou.cc/?p=41   listen.allowed_clients = 127.0.0.1 #允许访问FastCGI进程的IP, Set any to not restrict IP, if you want to set other host Nginx can also access this FPM process, listen to set the cost of access to IP. The default value is any.

Each address is separated by commas .  if not set or empty, allow any server to request a connection   listen.owner = www listen.group = www

listen.mode = 0666 #unix  socket Setting option, if you are using TCP access, Comment here.   user = www group = www #启动进程的帐户和组   pm = dynamic  #对于专用服务器,

PM can be set to static. #如何控制子进程, the options are static and dynamic. If you select static, Pm.max_children specifies the number of fixed child processes. If dynamic is selected, it is determined by the lower open parameter: pm.max_children #, the maximum number of pm.start_servers #, the number of processes at startup pm.min_spare_servers #, Guarantees the minimum number of idle processes, if the idle process is less than this value, creates a new subprocess pm.max_spare_servers #, guarantees the maximum number of idle processes, and cleans   pm.max_requests if the idle process is greater than this value  = 1000 #设置每个子进程重生之前服务的请求数 .  is useful for third-party modules that may have a memory leak .  if set to   ' 0 '   then always accept the request .  equivalent to  php_fcgi_max_requests  environment variable .  default value:  0.   Pm.status_path = /status #FPM状态页面的网址 .  If,  is not set, the status page .  default value is not accessible: none.  Munin monitoring will use the   ping.path = /ping #FPM监控页面的ping网址 .  The ping page cannot be accessed if,  is not set . 

This page is used to externally detect if FPM is alive and can respond to requests .  Note that you must start with a slash   (/).   Ping.response = pong #用于定义ping请求的返回相应 .  return to  HTTP 200   text/plain 

Rich Text .  default value:  pong.   request_terminate_timeout = 0 #设置单个请求的超时中止时间 .  This option may affect the ' max_execution_ ' in php.ini settings

Time ' .  set to   ' 0 '   means   ' off ' for some special reason the script is not aborted. You can try to change this option when 502 errors occur frequently.   Request_slowlog_timeout = 10s #当一个请求该设置的超时时间后, the corresponding PHP call stack information is fully written to the slow log .  set to   ' 0 '   Indicates   ' off '   slowlog = log/$pool. Log.slow #慢请求的记录日志, with request_slowlog_timeout use   Rlimit_ files = 1024 #设置文件打开描述符的rlimit限制 .  Default value:  system-defined value the default open handle is 1024, you can use  ulimit -n view, Ulimit

 -n 2048 modification. &nbSp

Rlimit_core = 0 #设置核心rlimit最大限制值 .  Available value:  ' unlimited '  , 0, or positive integer .  default value:  system-defined value.

  chroot = #启动时的Chroot目录 .  defined directory needs to be an absolute path .  chroot is not used if,  is not set.   chdir = #设置启动目录, automatically chdir to the directory .  the directory you defined at startup is the absolute path .  default:  current directory, or/directory (chroot time)   Catch_ Workers_output = yes #重定向运行过程中的stdout和stderr到主要的错误日志文件中 .  If, stdout  and  stderr are not set   will be redirected to  /dev/null .  default:  null according to FASTCGI rules.

Third, common mistakes and solution arrangement

Resource problems caused by 1,request_terminate_timeout

A request_terminate_timeout value that is set to 0 or too long may cause a file_get_contents resource problem.

If the remote resource requested by file_get_contents is slow, file_get_contents will be stuck there without timing out. We know php.ini inside Max_execution_time can set the maximum execution time for a PHP script, but in php-cgi (PHP-FPM), the parameter does not work. The real ability to control the maximum execution time of a PHP script is the request_terminate_timeout parameter in the php-fpm.conf configuration file.

The default value for Request_terminate_timeout is 0 seconds, which means that the PHP script will continue to execute. In this way, when all the php-cgi processes are stuck in the file_get_contents () function, the WebServer of this nginx+php is no longer able to process the new PHP request, and Nginx will return "502 bad Gateway" to the user. Modify this parameter to set a PHP script maximum execution time is necessary, but the symptom does not cure the root causes. For example, to 30s, if file_get_contents () to get the content of the Web page is slow, which means that 150 php-cgi process, only 5 requests per second, WebServer also difficult to avoid "502 bad Gateway." The solution is to set the request_terminate_timeout to 10s or a reasonable value, or to add a timeout parameter to the file_get_contents.

$ctx = stream_context_create (Array ('

http ' => Array (

' timeout ' => 10//Set a timeout in seconds

)

));

file_get_contents ($str, 0, $ctx);

Improper configuration of the 2,max_requests parameter may cause intermittent 502 errors:

pm.max_requests = 1000

Sets the number of requests for services before each subprocess is reborn. is useful for Third-party modules that may have memory leaks. If set to ' 0′, the request is always accepted. Equivalent to php_fcgi_max_requests environment variables. Default value: 0.
This configuration means that the process is automatically restarted when the number of requests processed by a php-cgi process accumulates to 500.

But why restart the process?

Generally in the project, we will use more or less the Third-party library of PHP, these third-party libraries often have memory leaks, if not periodically restart the php-cgi process, it is bound to cause memory usage continues to grow. Therefore, as a php-cgi manager, PHP-FPM provides such a monitoring function to restart the php-cgi process with a specified number of requests to ensure that the amount of memory is not increased.

Precisely because of this mechanism, in the high concurrency of the site, often led to 502 errors, I guess the reason is php-fpm to the request from the NGINX queue did not deal well. However, I am currently using PHP 5.3.2, do not know if there is still this problem in the PHP 5.3.3.

Our solution now is to set this value as large as possible, to minimize the number of php-cgi SPAWN and to improve overall performance. In our own actual production environment, we found that the memory leak is not obvious, so we set this value very large (204800). We should set this value according to their actual situation, not blindly increase.

In other words, the purpose of this mechanism is only to ensure that the php-cgi not excessive memory, why not through the detection of memory methods to deal with it? I very much agree with Gao Chunhui that it is a better solution to restart the php-cgi process by setting the peak intrinsic footprint of the process.

3,PHP-FPM slow log, debug and abnormal troubleshooting artifacts:

Request_slowlog_timeout sets a timeout parameter, Slowlog sets the location where the slow log is stored

Tail-f/var/log/www.php2.cc.log

The above command to see the slow-performing PHP process.
We can see the frequent network read more than, the MySQL query too slow problem, according to the information and then troubleshoot the problem has a very clear direction