PHP

The following settings provide an easier way to configure PHP handlers than the older External App + Script Handler method. If the older configuration already exists, it will continue to work.

LiteSpeed will also attempt to automatically detect PHP handlers for popular control panel environments. As such you may not need to configure PHP handlers at all.

Table of Contents

PHP Global Configuration

Detached Mode | Default PHP Versions | Control Panel | CloudLinux Alt PHP | SuEXEC handlers | Enable CRIU | CRIU Dump Min Reqs | CRIU debug

PHP Handler Definition

Handler ID | Command | Handled suffixes

PHP Handler Defaults

Max Connections | Environment | Initial Request Timeout (secs) | Retry Timeout (secs) | Connection Keepalive Timeout | Response Buffering | Back Log | Run On Start Up | Max Idle Time | Priority | Memory Soft Limit (bytes) | Memory Hard Limit (bytes) | Process Soft Limit | Process Hard Limit

Detached Mode

Description

Run PHP handler processes detached from the main LiteSpeed worker process.

Syntax

Select from radio box

Tips

This has the advantage of allowing LiteSpeed to continue using detached PHP handler processes after restarting as opposed to having to start new PHP handler processes.

Default PHP Versions

Description

A list of PHP versions to use as the default ".php" handler when a ".php" handler has not been explicitly set through a script handler or the "Handled suffixes" configuration.

The first available PHP handler, based on this list, will be used.

Syntax

Comma separated list of phpXX versions where XX is the combined major and minor PHP version number.

Example

php72, php71, php70, php56

Tips

All versions from php52 to php56 and php70 to php72 are available.

Control Panel

Description

Auto detect PHP handlers based on the control panel used.

Default value is "auto detect".

Syntax

Select from drop down list

CloudLinux Alt PHP

Description

Detect cloudlinux alt PHP handlers.

Default value is "Yes".

Syntax

Select from radio box

SuEXEC handlers

Description

List of file suffixes associated with handlers in suEXEC mode. All automatically discovered PHP handlers are in suEXEC mode.

Syntax

Comma separated list of file suffixes

Example

php, php5, php7

Tips

This setting can be left as "Not Set" in most situations.

Enable CRIU

Description

Enable Checkpoint/Restore In Userspace (CRIU) functionality.

Syntax

Select from radio box

CRIU Dump Min Reqs

Description

Minimum number of requests before triggering a CRIU dump.

Default value is 15.

Syntax

Positive integer number

CRIU debug

Description

Turn on CRIU debug logging.

Syntax

Select from radio box

Tips

Logged messages will be written to stderr.log.

PHP Handler Definition

Description

Add a custom PHP handler by only specifying "Handler ID", "Command", and optional "Handled Suffixes". This method will add an external application and associated script handler automatically.

External applications explicitly defined at the server level with the same "Handler ID" or "Command" will have a higher priority.

Tips

These settings may not be needed as automatically detected PHP handlers should work properly.

Handler ID

Description

Handler ID.

Well known IDs include "phpXX", "alt-phpXX", and "ea-phpXX".

Example

php72

Tips

When adding a handler with ID "php72", files with suffix ".php72" as well as MIME type "application/x-httpd-php72" will be automatically handled by this handler.

Command

Description

Command used to start the PHP handler.

Tips

This is usually the path to an "lsphp" binary.

Handled suffixes

Description

Extra file "suffixes" to be handled by this handler.

Tips

If a script handler has been configured explicitly for a provided file suffix, this configuration will be ignored.

Max Connections

Description

Specifies the maximum number of concurrent connections that can be established between the server and an external application. This setting controls how many requests can be processed concurrently by an external application, however, the real limit also depends on the external application itself. Setting this value higher will not help if the external application is not fast enough or cannot scale to a large number of concurrent requests.

Syntax

Integer number

Tips

Setting a high value does not directly translate to higher performance. Setting the limit to a value that will not overload the external application will provide the best performance/throughput.

Environment

Description

Specifies extra environment variables for the external application.

Syntax

Key=value. Multiple variables can be separated by "ENTER"

Initial Request Timeout (secs)

Description

Specifies the maximum time in seconds the server will wait for the external application to respond to the first request over a new established connection. If the server does not receive any data from the external application within this timeout limit, it will mark this connection as bad. This helps to identify communication problems with external applications as quickly as possible. If some requests take longer to process, increase this limit to avoid 503 error messages.

Syntax

Integer number

Retry Timeout (secs)

Description

Specifies the period of time that the server waits before retrying an external application that had a prior communication problem.

Syntax

Integer number

Connection Keepalive Timeout

Description

Specifies the maximum time in seconds to keep an idle persistent connection open.

When set to "-1", the connection will never timeout. When set to 0 or greater, the connection will be closed after this time in seconds has passed.

Syntax

int

Response Buffering

Description

Specifies whether to buffer responses received from external applications. If a "nph-" (Non-Parsed-Header) script is detected, buffering is turned off for responses with full HTTP headers.

Syntax

Select from drop down list

Back Log

Description

Specifies the backlog of the listening socket. Required if Auto Start is enabled.

Syntax

Integer number

Run On Start Up

Description

Specifies whether to start the external application at server start up. Only applicable to external applications that can manage their own child processes and where Instances value is set to "1". If enabled, external processes will be created at server startup instead of run-time.

Syntax

Select from radio box

Tips

If the configured external process has significant startup overhead, like a Rails app, then this option should be enabled to decrease first page response time.

Max Idle Time

Description

Specifies the maximum idle time before an external application is stopped by the server. When set to "-1", the external application will not be stopped by the server. The default value is "-1". This feature allows resources used by idle applications to be freed. It is especially useful in the mass hosting environment when you need to define many applications running in "setuid" mode for the sake of maximum security.

Syntax

Select from radio box

Tips

This feature is especially useful in the mass hosting environment. In order to prevent files owned by one virtual host from being accessed by the external application scripts of another virtual host, mass hosting often requires many different applications running at the same time in SetUID mode. Set this Max Idle Time low to prevent these external applications from idling unnecessarily.

Priority

Description

Specifies priority of the external application process. Value ranges from -20 to 20. A lower number means a higher priority. An external application process cannot have a higher priority than the web server. If this priority is set to a lower number than the server's, the server's priority will be used for this value.

Syntax

int

See Also

Server Priority

Memory Soft Limit (bytes)

Description

Specifies the memory consumption limit in bytes for an external application process or an external application started by the server.

The main purpose of this limit is to prevent excessive memory usage because of software bugs or intentional attacks, not to impose a limit on normal usage. Make sure to leave enough head room, otherwise your application may fail and 503 error may be returned. It can be set at the server- level or at an individual external application level. The server-level limit will be used if it is not set at the individual application level.

The operating system's default setting will be used if the value is absent at both levels or set to 0.

Syntax

Integer number

Tips

Do not over adjust this limit. This may result in 503 errors if your application needs more memory.

Memory Hard Limit (bytes)

Description

Much the same as Memory Soft Limit (bytes), except the soft limit can be raised up to the hard limit from within a user process. The hard limit can be set at server level or at an individual external application level. The server-level limit will be used if it is not set at an individual application level.

The operating system's default will be used if the value is absent at both levels or set to 0.

Syntax

Integer number

Tips

Do not over adjust this limit. This may result in 503 errors if your application need more memory.

Process Soft Limit

Description

Limits the total number of processes that can be created on behalf of a user. All existing processes will be counted against this limit, not just new processes to be started.

The limit can be set at the server level or at an individual external application level. The server-level limit will be used if it is not set at an individual application level. The operating system's default setting will be used if this value is 0 or absent at both levels.

Syntax

Integer number

Tips

To control how many processes LSWS will make for users in suEXEC mode, use the suEXEC Max Conn setting. PHP scripts can call for forking processes and the number of processes needed for normal functioning can be above the suEXEC Max Conn setting. The main purpose of this limit is as a last line of defense to prevent fork bombs and other attacks caused by PHP processes creating other processes.
Setting this setting too low can severely hurt functionality. The setting will thus be ignored below certain levels.
When using suEXEC Daemon mode, the actual process limit will be higher than this setting to make sure parent processes are not limited.

Process Hard Limit

Description

Much the same as Process Soft Limit, except the soft limit can be raised up to the hard limit from within a user process. The hard limit can be set at the server level or at an individual external application level. The server-level limit will be used if it is not set at an individual application level. The operating system's default value will be used if the value is absent at both levels or set to 0.

Syntax

Integer number