List of global php-fpm.conf directives

pid string

Path to PID file. Default value: none.

error_log string

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.

log_level string

Error log level. Possible values: alert, error, warning, notice, debug. Default value: notice.

log_limit int

Log limit for the logged lines which allows to log messages longer than 1024 characters without wrapping. Default value: 1024. Available as of PHP 7.3.0.

log_buffering bool

Experimental logging without extra buffering. Default value: yes. Available as of PHP 7.3.0.

syslog.facility string

used to specify what type of program is logging the message. Default value: daemon.

syslog.ident string

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.

emergency_restart_threshold int

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).

emergency_restart_interval mixed

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).

process_control_timeout mixed

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.

process.max int

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.

process.priority int

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.

daemonize bool

Send FPM to background. Set to 'no' to keep FPM in foreground for debugging. Default value: yes.

rlimit_files int

Set open file descriptor rlimit for the master process. Default value: system defined value.

rlimit_core int

Set max core size rlimit for the master process. Default value: 0.

events.mechanism string

Specify the event mechanism FPM will use. The following is available: select, pool, epoll, kqueue (*BSD), port (Solaris). Default value: not set (auto detection).

systemd_interval int

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.

List of pool directives

With FPM you can run several pools of processes with different setting. These are settings that can be tweaked per pool.

listen string

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.

listen.backlog int

Set listen(2) backlog. A value of -1 means maximum on BSD systems. Default value: -1 (FreeBSD or OpenBSD) or 511 (Linux and other platforms).

listen.allowed_clients string

List of IPv4 or IPv6 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: not set (any ip address accepted).

listen.owner string

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.

listen.group string

See listen.owner.

listen.mode string

See listen.owner.

listen.acl_users string

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.

listen.acl_groups string

See listen.acl_users. Value is a comma separated list of group names.

user string

Unix user of FPM processes. This option is mandatory.

group string

Unix group of FPM processes. If not set, the default user's group is used.

pm string

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.

pm.max_children int

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.

pm.start_servers int

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.

pm.min_spare_servers int

The desired minimum number of idle server processes. Used only when pm is set to dynamic. Also mandatory in this case.

pm.max_spare_servers int

The desired maximum number of idle server processes. Used only when pm is set to dynamic. Also mandatory in this case.

pm.max_spawn_rate int

The number of rate to spawn child processes at once. Used only when pm is set to dynamic. Default value: 32

pm.process_idle_timeout mixed

The number of seconds after which an idle process will be killed. Used only when pm is set to ondemand. Available units: s(econds)(default), m(inutes), h(ours), or d(ays). Default value: 10s.

pm.max_requests int

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.

pm.status_listen string

The address on which to accept FastCGI status request. This creates a new invisible pool that can handle requests independently. This is useful if the main pool is busy with long running requests because it is still possible to get the FPM status page before finishing the long running requests. The syntax is the same as for listen directive. Default value: none.

pm.status_path string

The URI to view the FPM status page. This value must start with a leading slash (/). If this value is not set, no URI will be recognized as a status page. Default value: none.

ping.path string

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 (/).

ping.response string

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.

process.priority int

Specify the nice(2) priority to apply to the worker process (only if set). The value can vary from -19 (highest priority) to 20 (lower priority). Default value: not set.

process.dumpable bool

Set the process dumpable flag (PR_SET_DUMPABLE prctl) even if the process user or group is different than the master process user. It allows to create process core dump and ptrace the process for the pool user. Default Value: no. Since PHP 7.0.29, 7.1.17 and 7.2.5.

prefix string

Specify prefix for path evaluation

request_terminate_timeout mixed

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.

request_terminate_timeout_track_finished bool

The timeout set by request_terminate_timeout is not engaged after a fastcgi_finish_request or when application has finished and internal shutdown functions are being called. This directive will enable timeout limit to be applied unconditionally even in such cases. Default value: no. Since PHP 7.3.0.

request_slowlog_timeout mixed

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.

request_slowlog_trace_depth int

The depth of slowlog log stack trace. Default value: 20. Since PHP 7.2.0.

slowlog string

The log file for slow requests. Default value: #INSTALL_PREFIX#/log/php-fpm.log.slow.

rlimit_files int

Set open file descriptor rlimit for child processes in this pool. Default value: system defined value.

rlimit_core int

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 string

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 string

Chdir to this directory at the start. This value must be an absolute path. Default value: current directory or / when chroot.

catch_workers_output bool

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.

decorate_workers_output bool

Enable the output decoration for workers output when catch_workers_output is enabled. Default value: yes. Available as of PHP 7.3.0.

clear_env bool

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. Default value: Yes.

security.limit_extensions string

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 .phar

apparmor_hat string

If AppArmor is enabled, it allows to change a hat. Default value: not set

access.log string

The access log file. Default value: not set

access.format string

The access log format. Default value: "%R - %u %t \"%m %r\" %s":

Valid options

Placeholder	Description
%C	%CPU
%d	duration µs
%e	fastcgi env
%f	script
%l	content length
%m	method
%M	memory
%n	pool name
%o	header output
%p	PID
%q	query string
%Q	the glue between %q and %r
%r	request URI
%R	remote IP address
%s	status
%T	time
%t	time
%u	remote user

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.

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 www@my.domain.com
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 overridden with ini_set().

PHP settings can be set in the webserver configuration.

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";

Bilginize: Pools are not a security mechanism, because they do not provide full separation; e.g. all pools would use a single OPcache instance.