FPM uses php.ini syntax for its configuration file - php-fpm.conf, and pool configuration files.
Path to PID file. Default value: none.
Path to error log file. Default value: #INSTALL_PREFIX#/log/php-fpm.log. If it's set to "syslog", log is sent to syslogd instead of being written in a local file.
Error log level. Possible values: alert, error, warning, notice, debug. Default value: notice.
used to specify what type of program is logging the message. Default value: daemon.
Prepended to every message. If you have multiple FPM instances running on the same server, you can change the default value which must suit common needs. Default value: php-fpm.
If this number of child processes exit with SIGSEGV or SIGBUS within the time interval set by emergency_restart_interval then FPM will restart. A value of 0 means 'Off'. Default value: 0 (Off).
Interval of time used by emergency_restart_interval to determine when a graceful restart will be initiated. This can be useful to work around accidental corruptions in an accelerator's shared memory. Available Units: s(econds), m(inutes), h(ours), or d(ays). Default Unit: seconds. Default value: 0 (Off).
Time limit for child processes to wait for a reaction on signals from master. Available units: s(econds), m(inutes), h(ours), or d(ays) Default Unit: seconds. Default value: 0.
The maximum number of processes FPM will fork. This has been design to control the global number of processes when using dynamic PM within a lot of pools. Use it with caution. Default value: 0.
Specify the nice(2) priority to apply to the master process (only if set) The value can vary from -19 (highest priority) to 20 (lower priority). Default value: not set.
Send FPM to background. Set to 'no' to keep FPM in foreground for debugging. Default value: yes.
Set open file descriptor rlimit for the master process. Default value: Set open file descriptor rlimit for the master process.
Set max core size rlimit for the master process. Default value: 0.
Specify the event mechanism FPM will use. The following is available: select, pool, epoll, kqueue (*BSD), port (Solaris). Default value: not set (auto detection).
When FPM is build with systemd integration, specify the interval, in second, between health report notification to systemd. Set to 0 to disable. Default value: 10.
With FPM you can run several pools of processes with different setting. These are settings that can be tweaked per pool.
The address on which to accept FastCGI requests. Valid syntaxes are: 'ip.add.re.ss:port', 'port', '/path/to/unix/socket'. This option is mandatory for each pool.
Set listen(2) backlog. A value of '-1' means unlimited. Default value: -1.
List of IPv4 addresses of FastCGI clients which are allowed to connect. Equivalent to the FCGI_WEB_SERVER_ADDRS environment variable in the original PHP FastCGI (5.2.2+). Makes sense only with a tcp listening socket. Each address must be separated by a comma. If this value is left blank, connections will be accepted from any ip address. Default value: any. IPv6 addresses are allowed since 5.5.20 and 5.6.4.
Set permissions for unix socket, if one is used. In Linux, read/write permissions must be set in order to allow connections from a web server. Many BSD-derived systems allow connections regardless of permissions. Default values: user and group are set as the running user, mode is set to 0660.
When POSIX Access Control Lists are supported you can set them using this option. When set, listen.owner and listen.group are ignored. Value is a comma separated list of user names. Since PHP 5.6.5.
See listen.acl_users. Value is a comma separated list of group names. Since PHP 5.6.5.
Unix user of FPM processes. This option is mandatory.
Unix group of FPM processes. If not set, the default user's group is used.
Choose how the process manager will control the number of child processes. Possible values: static, ondemand, dynamic. This option is mandatory.
static - the number of child processes is fixed (pm.max_children).
ondemand - the processes spawn on demand (when requested, as opposed to dynamic, where pm.start_servers are started when the service is started.
dynamic - the number of child processes is set dynamically based on the following directives: pm.max_children, pm.start_servers, pm.min_spare_servers, pm.max_spare_servers.
The number of child processes to be created when pm is set to static and the maximum number of child processes to be created when pm is set to dynamic. This option is mandatory.
This option sets the limit on the number of simultaneous requests that will be served. Equivalent to the ApacheMaxClients directive with mpm_prefork and to the PHP_FCGI_CHILDREN environment variable in the original PHP FastCGI.
The number of child processes created on startup. Used only when pm is set to dynamic. Default Value: min_spare_servers + (max_spare_servers - min_spare_servers) / 2.
The desired minimum number of idle server processes. Used only when pm is set to dynamic. Also mandatory in this case.
The desired maximum number of idle server processes. Used only when pm is set to dynamic. Also mandatory in this case.
The number of requests each child process should execute before respawning. This can be useful to work around memory leaks in 3rd party libraries. For endless request processing specify '0'. Equivalent to PHP_FCGI_MAX_REQUESTS. Default value: 0.
The URI to view the FPM status page. If this value is not set, no URI will be recognized as a status page. Default value: none.
The ping URI to call the monitoring page of FPM. If this value is not set, no URI will be recognized as a ping page. This could be used to test from outside that FPM is alive and responding. Please note that the value must start with a leading slash (/).
This directive may be used to customize the response to a ping request. The response is formatted as text/plain with a 200 response code. Default value: pong.
The timeout for serving a single request after which the worker process will be killed. This option should be used when the 'max_execution_time' ini option does not stop script execution for some reason. A value of '0' means 'Off'. Available units: s(econds)(default), m(inutes), h(ours), or d(ays). Default value: 0.
The timeout for serving a single request after which a PHP backtrace will be dumped to the 'slowlog' file. A value of '0' means 'Off'. Available units: s(econds)(default), m(inutes), h(ours), or d(ays). Default value: 0.
The log file for slow requests. Default value: #INSTALL_PREFIX#/log/php-fpm.log.slow.
Set open file descriptor rlimit for child processes in this pool. Default value: system defined value.
Set max core size rlimit for child processes in this pool. Possible Values: 'unlimited' or an integer greater or equal to 0. Default value: system defined value.
Chroot to this directory at the start. This value must be defined as an absolute path. When this value is not set, chroot is not used.
Chdir to this directory at the start. This value must be an absolute path. Default value: current directory or / when chroot.
Redirect worker stdout and stderr into main error log. If not set, stdout and stderr will be redirected to /dev/null according to FastCGI specs. Default value: no.
Clear environment in FPM workers. Prevents arbitrary environment variables from reaching FPM worker processes by clearing the environment in workers before env vars specified in this pool configuration are added. Since PHP 5.4.27, 5.5.11, and 5.6.0. Default value: Yes.
Limits the extensions of the main script FPM will allow to parse. This can prevent configuration mistakes on the web server side. You should only limit FPM to .php extensions to prevent malicious users to use other extensions to execute php code. Default value: .php.
It's possible to pass additional environment variables and update PHP settings of a certain pool. To do this, you need to add the following options to the pool configuration file.
Example #1 Passing environment variables and PHP settings to a pool
env[HOSTNAME] = $HOSTNAME env[PATH] = /usr/local/bin:/usr/bin:/bin env[TMP] = /tmp env[TMPDIR] = /tmp env[TEMP] = /tmp php_admin_value[sendmail_path] = /usr/sbin/sendmail -t -i -f firstname.lastname@example.org php_flag[display_errors] = off php_admin_value[error_log] = /var/log/fpm-php.www.log php_admin_flag[log_errors] = on php_admin_value[memory_limit] = 32M
Settings defined with php_admin_value and php_admin_flag cannot be overriden with ini_set().
As of 5.3.3, PHP settings are also possible to be set in webserver.
Example #2 set PHP settings in nginx.conf
set $php_value "pcre.backtrack_limit=424242"; set $php_value "$php_value \n pcre.recursion_limit=99999"; fastcgi_param PHP_VALUE $php_value; fastcgi_param PHP_ADMIN_VALUE "open_basedir=/var/www/htdocs";
Because these settings are passed to php-fpm as fastcgi headers, php-fpm should not be bound to a worldwide accessible address. Otherwise, anyone could alter the PHP configuration options. See also listen.allowed_clients.