AFPA directives

These configuration parameters control the Advanced Fast Path Architecture (AFPA) feature in IBM HTTP Server.

The fast response cache accelerator (FRCA) utilizes a special high-performance component, based on the IBM Advanced Fast Path Architecture, from which the AFPA prefix is derived. We can configure FRCA for IPV4. IPV6 is not supported.


AfpaBindLogger directive

Use the AfpaBindLogger directive to bind the fast response cache accelerator (FRCA) logging thread in the kernel to a specific processor.

The format of the command is AfpaBindLogger [-1, 0, 1, ..., n], where -1 leaves the logging thread unbound and a number from 0 to total number of processors on the system, binds the logging thread to that processor.
Directive Description
Scope One per physical Apache server
Default (-1)
Notes Valid on AIX® operating systems only.


AfpaCache directive

The AfpaCache directive turns the fast response cache accelerator (FRCA) on or off for a particular scope (such as a directory). The AfpaCache directive applies to all descendants in a scope, unless otherwise modified by another directive.
Directive Description
Scope Server configuration, virtual host, directory
Syntax On or off
Usage AfpaCache on
Override Options
Multiple instances in the configuration file Allowed
Notes Valid on Windows 32-bit and AIX operating systems.


AfpaDynacacheMax directive

The AfpaDynacacheMax directive is used on Windows operating systems to control the total amount of memory utilized for caching servlets and JavaServer Pages files.

When static files are cached, there is very little overhead for each entry since the file itself does not take up space in the cache, just the file handle. However, for servlets and JavaServer Pages files, the body of the response is stored in physical memory, so care must be taken to avoid consuming all available memory. Without this directive, the fast response cache accelerator will automatically set the upper-bound to be approximately one eighth of physical memory. Use the directive to override that default.
Directive Description
Syntax AfpaDynacacheMax  size (Megabytes)
Scope One per physical Apache server
Notes Valid on Windows 32-bit operating systems


AfpaEnable directive

The AfpaEnable directive enables the fast response cache accelerator (FRCA). If the AfpaEnable directive is present and mod_afpa_cache.so is loaded, FRCA listens on the port specified by the AfpaPort directive.
Directive Description
Syntax AfpaEnable
Scope One per physical Apache server
Notes Valid on AIX and Windows operating systems.


AfpaLogFile directive

The AfpaLogFile directive defines the fast response cache accelerator (FRCA) log file name, location, and logging format.
Directive Description
Scope One per physical Apache server
Syntax AfpaLogFile log_file_name [CLF | ECLF | V-CLF | V-ECLF| BINARY]
Notes Valid on AIX and Windows 32-bit operating systems. On Windows 32-bit operating systems, the current date is used as the file type for the log file, and the log file is automatically rolled over at midnight each day.
The log formats are as follows:

  • CLF = Common Log Format

  • ECLF = Extended Common Log Format

  • V-CLF = Common Log Format with virtual host information

  • V-ECLF = Extended Common Log Format with virtual host information

  • BINARY = Binary log with virtual host information


AfpaLogging directive

The AfpaLogging directive turns the fast response cache accelerator (FRCA) logging on or off.
Directive Description
Scope One per physical Apache server
Syntax AfpaLogging On | Off
Notes Valid only on AIX operating systems.


AfpaMaxCache directive

The AfpaMaxCache directive specifies the maximum file size inserted into the fast response cache accelerator (FRCA) cache.
Directive Description
Syntax AfpaMaxCache [size (bytes)]
Scope One per physical Apache server
Default none
Notes Valid only on AIX operating systems.


AfpaMinCache directive

The AfpaMinCache directive specifies the minimum file size inserted into the fast response cache accelerator (FRCA) cache.
Directive Description
Syntax AfpaMinCache [size]
Scope One per physical Apache server
Default none
Notes Valid only on AIX operating systems.


AfpaPort directive

The AfpaPort directive tells the FRCA on which TCP port to listen. The AfpaPort directive issues a listen command for all TCP network adapters that are active on the server machine. The listen command is effective for all TCP addresses.
Directive Description
Syntax AfpaPort port number
Scope One directive per server
Notes Valid only on AIX and Windows 32-bit operating systems


AfpaRevalidationTimeout directive

The AfpaRevalidationTimeout directive sets the time interval for revalidation of a cached object. When the RevalidationTimeout is exceeded for a cached object, a fresh copy is cached.
Directive Description
Syntax AfpaRevalidationTimeout [value]
Scope Global
Default 60 seconds
Notes Valid on AIX operating systems only.


AfpaSendServerHeader

The AfpaSendServerHeader directive specifies whether or not the fast response cache accelerator (FRCA) sends the HTTP Server header in the response.
Directive Description
Syntax AfpaSendServerHeader true or false
Scope One per physical Apache server
Default true
Notes Valid only on AIX operating systems.