CHGHTTPA (Change HTTP Attributes)

Note: To use this command, have the 5722-DG1 (HTTP Server) product installed.

 

Purpose

Use the Change HTTP Attributes (CHGHTTPA) command to change the World Wide Web Hypertext Transfer Protocol (HTTP) server attributes.

Take special note...: When you use this command to change HTTP attributes, then the changes apply to all servers and server instances, with the following exceptions:

The changes take effect the next time the server is started either by the Start TCP/IP (STRTCP) command or by the Start TCP/IP Server (STRTCPSVR) command.

Restriction: You must have *IOSYSCFG special authority to use this command.

Parameters

AUTOSTART
Specifies whether to automatically start the server when you start TCP/IP (Transmission Control Protocol/Internet Protocol) by using the STRTCP command. When you start HTTP by using the STRTCPSVR command, then the server starts regardless of the value of this parameter. If you start STRTCPSVR *HTTP, and the server is already running, then the server denies the start request.

If you have multiple server instances of your server configured, make sure that they all work together before enabling AUTOSTART. If you specify CHGHTTPA AUTOSTART(*YES), when you use the STRTCP command, all server instances start.

The possible values are:

*SAME
The AUTOSTART value does not change if it was previously set. Otherwise, *NO is used.
*NO
Do not start the HTTP server when the STRTCP command is issued. If you do not intend to use HTTP, set this parameter to *NO.
*YES
Start the HTTP server when the STRTCP command is issued.

NBRSVR
Specifies the minimum number of requests the server can process simultaneously. This parameter also specifies the maximum number of requests the server can process simultaneously.

Use the maximum value to help prevent system resources from being exhausted during peak HTTP activity. Set this value in accordance with the amount of HTTP activity that you anticipate and the system reources that are available. If you reach the maximum number during peak loads, additional connection requests remain on the sockets connection request backlog until a server job becomes available to service the connection request.

The number of threads that you specify is the number of worker threads that the server will use for handling requests.

The actual number of threads for the server will be greater than the minimum and the maximum value that you specify on NBRSVR. The server does not count other threads that it uses for an instance in the number of threads that you specify for NBRSVR. See Example 4 in STRTCPSVR SERVER(*HTTP) for information on threads started.

The maximum number of server threads that you specify cannot be less than the minimum number of server threads specified.

Element 1: Minimum number of server threads

The possible values are:

*SAME
The minimum number of server threads that was previously set does not change. The default value is 10.
*DFT
Specifies the default value of 10 for the minimum number of server threads.
minimum-number-of-server-threads
The minimum number of server threads requested to start. The valid range is 1 through 200 server threads.

Element 2: Maximum number of server threads

The possible values are:

*SAME
The maximum number of server threads previously set does not change. Otherwise, 40 is used.
*NOMAX
There is no limit to the maximum number of server threads that is allowed to start.
*DFT
The maximum number of server threads is set to the default value of 40. If you allow this parameter to default, the minimum number of server threads specified cannot be greater than 40.
maximum-number-of-server-threads
The maximum number of server threads that is allowed to start. The valid range is 1 through 999 server threads. This value must be greater than the value specified for the minimum number of server threads.

CCSID
Use this value to determine the American National Standard Code for Information Interchange (ASCII) coded-character set identifier (CCSID) value. Use this value for translations when doing ASCII-to-extended binary-coded decimal interchange code (EBCDIC) and EBCDIC-to-ASCII mapping. Use this value if the World Wide Web (WWW) browser does not define the character set and code page in the MIME header. Mapping is determined using one of the following:

  • The MIME header values

  • Both the specified ASCII CCSID and the EBCDIC default CCSID of the job.

You can optionally use outgoing and incoming mapping with the mapping tables that the TBLHTTPOUT and TBLHTTPIN parameters define. Normally, you set the TBLHTTPOUT and TBLHTTPIN parameters to the default of *CCSID or *DFT. Both should indicate that the server uses the CCSID parameter value for mapping.

If you use a mapping table for outgoing mapping, you can specify a table object in the TBLHTTPOUT parameter. Then you use this table object for outgoing mapping instead of the CCSID value.

You can change incoming mapping to use a mapping table in the same manner by specifying a table object in the TBLHTTPIN parameter. This mapping table then overrides the specified CCSID value and works with incoming mapping.

The possible values are:

*SAME
The CCSID value that was previously set does not change; otherwise, 00819 "ISO 8859-1 8-bit ASCII" is used.
*DFT
The CCSID value is 00819 "ISO 8859-1 8-bit ASCII".
CCSID-value
The requested CCSID value is used. This value is validated to ensure a valid ASCII CCSID has been requested.

TBLHTTPOUT
Specifies the table object that is to be used to map all outgoing server data in HTTP. Outgoing server data is mapped from EBCDIC to ASCII.

If a table object is specified for the TBLHTTPOUT parameter, the table object is used for outgoing mapping. Otherwise, the CCSID parameter is used to determine outgoing mapping.

The possible values are:

*SAME
The TBLHTTPOUT value does not change if it was previously ser; otherwise, *CCSID is used.
*CCSID
The server uses the CCSID parameter to determine outgoing mapping.
*DFT
The server uses the CCSID parameter to determine outgoing mapping.

You can qualify the name of the outgoing mapping table by using one of the following library values:

*LIBL
The server searches all libraries in the job's library list until it finds a match.
*CURLIB
The current library for the job is searched. If no library is specified as the current library for the job, the QGPL library is used.
library-name
Specifies the name of the library to search.
outgoing-mapping-table
Specify the table object to be used for mapping the outgoing HTTP server data.

TBLHTTPIN
Specifies the table object that is used to map all incoming server data in HTTP. Incoming server data is mapped for ASCII to EBCDIC.

If a table object is specified for the TBLHTTPIN parameter, the table object is used for incoming mapping. Otherwise, the CCSID parameter is used to determine incoming mapping.

The possible values are:

*SAME
The TBLHTTPIN value does not change if it was previously set; otherwise, *CCSID is used.
*CCSID
The CCSID parameter is used to determine incoming mapping.
*DFT
The CCSID parameter is used to determine incoming mapping.

You can qualify the name of the incoming mapping table by using one of the following library values:

*LIBL
All libraries in the job's library list are searched until the first match is found.
*CURLIB
The server searches the current library for the job. If you do not specify a library as the current library for the job, then the server uses the QGPL library.
library-name
Specifies the name of the library to be searched.
incoming-mapping-table
Specify the table object to use for mapping the incoming server data.

Examples for CHGHTTPA

Example 1: Changing the HTTP Attributes to Automatically Start the Server when you use the Start TCP/IP (STRTCP) CL command. 

CHGHTTPA  AUTOSTART(*YES)

This command indicates that the server will automatically start up the next time that you use the STRTCP command. Server instances will start automatically if they do not have AUTOSTART overridden.

Example 2: Changing the HTTP Attributes to have a minimum of 10 and a maximum of 50 server threads. 

CHGHTTPA  NBRSRV(10 50)

This command indicates that 10 server threads will start automatically when you next start up HTTP. The server allows a maximum of 50 server threads to start to handle incoming HTTP requests.

Example 3: Using the Server Mapping Tables 

CHGHTTPA  TBLHTTPOUT(*LIBL/TSTHTTPO)
   TBLHTTPIN(*LIBL/TSTHTTPI)

This command indicates that the next time the server is started, the server wil have the following characteristics:

Error messages for CHGHTTPA

*ESCAPE messages

TCP8050
*IOSYSCFG authority required to use &1.