PHP settings for Exponential #

This page is for system administrators who configure PHP for Exponential sites, on a shared server, a panel or a dedicated machine. It answers: which php.ini values the installer insists on, what a production pool should set, which PHP functions features of Exponential call (and what stops working when a host disables them), and where the settings live when Velocity or FrankenPHP runs PHP instead of PHP-FPM.

Contents #

1. What the installer checks
2. A production set for a pool
3. Time zone
4. Error display
5. OPcache under PHP-FPM
6. Functions some features call
7. Timeouts
8. Velocity and FrankenPHP
9. Applying a change
10. Checklist
11. Related pages

What the installer checks #

From chapter 2.5 and settings/setup.ini:

The 64M floor is what the installer needs, not what a running site should have. The administration's Setup > System information health check reports a memory_limit below 128M as a failure and below 256M as a warning, and a max_execution_time below 30 seconds on a web server (System information, health checks).

A production set for a pool #

The minimal production set from chapter 2, as a PHP-FPM pool's php_admin_value lines or in php.ini:

memory_limit = 256M
max_execution_time = 60
date.timezone = Europe/Berlin
file_uploads = On
upload_max_filesize = 64M
post_max_size = 64M
allow_url_fopen = On
variables_order = "EGPCS"

The values above the minimums are suggestions, not requirements: size them for the largest file a customer uploads and the longest import run through the browser. A plan can state its upload limit as one of its properties.

Time zone #

index.php sets UTC when php.ini has no date.timezone; the installer's test fails only in that case. A site can also set its own zone in settings/site.ini, [TimeZoneSettings] TimeZone, applied by the kernel on every request. For a host, setting date.timezone in every pool to the zone of the server (or UTC) is enough; customers set their own in the site's settings.

Error display #

From chapter 13.4: in the php.ini of PHP-FPM set

display_errors = Off
log_errors = On
expose_php = Off

The System information page flags display_errors as a health problem. Exponential's own debug output is a separate switch, site.ini [DebugSettings] DebugOutput, which must be off on production as well.

OPcache under PHP-FPM #

From chapter 10.12:

opcache.enable=1
opcache.memory_consumption=256
opcache.max_accelerated_files=20000
opcache.interned_strings_buffer=32
; keep timestamp checks on: Exponential rewrites PHP cache files (INI caches,
; compiled templates, expiry.php) under the same name
opcache.validate_timestamps=1
opcache.revalidate_freq=2

Functions some features call #

Hosts often list functions in disable_functions. These features of Exponential call functions that are commonly on such lists; the site keeps running without them, but the feature does not work:

A command-line PHP for cron and Velocity usually has its own php.ini without such a list; check with php --ini.

Timeouts #

• max_execution_time limits PHP's own CPU time; under PHP-FPM the hard limit of a request is the pool's request_terminate_timeout (off unless set) (chapter 9.2).
• With SQLite, keep [DatabaseSettings] SQLiteTransactionWait (25 seconds shipped) below the request timeout, or a waiting writer is killed before the driver can report (SQLite for hosts).
• The setup wizard's configuration step on MongoDB can take one to three minutes; raise request_terminate_timeout for that install or use the console (MongoDB for hosts).
• Sessions: site.ini [Session] SessionTimeout (shipped 31104000 seconds, 360 days) overwrites session.gc_maxlifetime with PHP's own session handler.

Velocity and FrankenPHP #

Velocity runs PHP as command line processes and passes its own options from settings/velocity.ini, [PHPSettings] IniOptions[]. The shipped list turns on OPcache for the command line (opcache.enable_cli=1), sets memory_consumption=512, max_accelerated_files=20000, interned_strings_buffer=64, opcache.revalidate_freq=0, opcache.file_update_protection=0 and apc.shm_size=256M. The two OPcache values differ from PHP-FPM on purpose: a Velocity worker is one long request, and with the PHP-FPM values it would keep serving stale cache files (chapter 10.12). Put changes in settings/override/velocity.ini.append.php, never in the shipped file.

FrankenPHP reads no php.ini of the machine. settings/velocity.ini, [FrankenPHPSettings] IniOptions[] ships display_errors=Off, log_errors=On, memory_limit=512M, opcache.enable=1, post_max_size=64M and upload_max_filesize=32M; PHPIniFile names a php.ini of your own instead (chapter 8.4).

Applying a change #

After editing php.ini or a pool, reload what runs PHP: PHP-FPM, Apache with mod_php, or Velocity (php bin/php/console exp:velocity restart). php --ini shows which files the command line PHP reads; the web PHP may read others. A change that "does not work" is most often a change to the file the other PHP reads.

Checklist #

• To do: memory_limit 256M or more for production pools (64M is only the installer's floor).
• To do: max_execution_time, date.timezone, file_uploads, allow_url_fopen and variables_order set.
• To do: Upload limits stated in the plan and set in the pool.
• To do: display_errors=Off, log_errors=On, expose_php=Off.
• To do: OPcache on, with timestamp checks kept on.
• To do: disable_functions reviewed against the table above.
• To do: Velocity and FrankenPHP settings changed in settings/override/velocity.ini.append.php only.

Related pages #

• PHP versions and extensions
• PHP-FPM tuning and OPcache
• PHP selection and FPM pools
• Chapter 2.5: php.ini settings
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.