App Server Settings
Table of Contents
Ruby Path | Run-Time Mode | Max Connections | Environment | Initial Request Timeout (secs) | Retry Timeout (secs) | Connection Keepalive Timeout | Response Buffering | Max Idle Time | Back Log | Run On Start Up | Priority | Memory Soft Limit (bytes) | Memory Hard Limit (bytes) | Process Soft Limit | Process Hard Limit
WSGI Path | Run-Time Mode | Max Connections | Environment | Initial Request Timeout (secs) | Retry Timeout (secs) | Connection Keepalive Timeout | Response Buffering | Max Idle Time | Back Log | Run On Start Up | Priority | Memory Soft Limit (bytes) | Memory Hard Limit (bytes) | Process Soft Limit | Process Hard Limit
Node Path | Run-Time Mode | Max Connections | Environment | Initial Request Timeout (secs) | Retry Timeout (secs) | Connection Keepalive Timeout | Response Buffering | Max Idle Time | Back Log | Run On Start Up | Priority | Memory Soft Limit (bytes) | Memory Hard Limit (bytes) | Process Soft Limit | Process Hard Limit
Rack/Rails Default Settings⇑
Description
Default configurations for Rack/Rails applications. These settings can be overriden at the context level.
Ruby Path⇑
Description
Path to Ruby executable. Generally, it is /usr/bin/ruby or /usr/local/bin/ruby depending on where Ruby has been installed to.
Syntax
Absolute path
Run-Time Mode⇑
Description
Specifies which mode the application will be running as: "Development", "Production", or "Staging". The default is "Production".
Syntax
Select from drop down list
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
Max Idle Time⇑
Description
Specifies the maximum idle time before an external application is stopped by the server, freeing idle resources. When set to "-1", the external application will not be stopped by the server unless running in ProcessGroup mode where idle external applications will be stopped after 30 seconds. The default value is "-1".
Syntax
Select from radio box
Tips
This feature is especially useful in the mass hosting environment where, in order to prevent files owned by one virtual host from being accessed by the external application scripts of another virtual host, many different applications are run at the same time in SetUID mode. Set this value low to prevent these external applications from idling unnecessarily.
Back Log⇑
Description
Specifies the backlog of the listening socket. Required if Start By Server 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.
When selecting "Yes (Detached mode)", all detached process can be restarted at the Server level or Virtual Host level by touching the '.lsphp_restart.txt' file under the $SERVER_ROOT/admin/tmp/ or $VH_ROOT/ directory respectively.
Default value: Yes (Detached mode)
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.
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
PHP scripts can call for forking processes. 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 Run On Start Up is set to "Yes (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
Python WSGI Default Settings⇑
Description
Default configurations for Python WSGI applications. These settings can be overriden at the context level.
WSGI Path⇑
Description
Path to LiteSpeed Python Web Server Gateway Interface executable (lswsgi).
This executable is created by compiling Python with LiteSpeed's WSGI LSAPI module.
Syntax
Absolute path
Node.js App Default Settings⇑
Description
Default configurations for Node.js applications. These settings can be overriden at the context level.
Node Path⇑
Description
Path to Node.js executable.
Syntax
Absolute path