CICS® Web
support in CICS Transaction Server for z/OS®, Version 3 Release 1 has
many enhancements to provide automatic and administrator control of functions
that were previously handled by user-replaceable programs. In particular,
you are recommended to investigate migration possibilities for the following
elements of your CICS Web support architecture:
- You should usually be able to replace the request processing functions
of an existing analyzer program with URIMAP resource definitions, which can
be changed and controlled using CICS system programming commands. URIMAP definitions can be used to match the URLs of requests and map
them to application programs, and specify a converter program and alias transaction.
If your analyzer program is customized to provide additional functions, you
can continue to use it instead of a URIMAP definition, or you can combine
it with a URIMAP definition. While migrating to the use of URIMAPs:
- You can introduce URIMAP resource definitions progressively
for a small number of requests at a time. Depending on the type
of processing carried out by your analyzer program, and the type of application
that handles the request, you can choose whether or not to continue using
the analyzer program in the processing path for each request.
- You might prefer to select and publish new URLs for requests
handled by URIMAP resource definitions, rather than retaining your existing
URLs. When you are ready to discontinue the use of the old processing
path for a request, you can set up a URIMAP definition to permanently redirect
requests from the old URL to the new URL.
- Ensure that the analyzer program specified on the TCPIPSERVICE
definition still contains basic error handling procedures, even if it is no
longer involved in the processing path for requests. The analyzer
program must still be present, and it receives requests if URIMAP matching
fails.
- For application programs that do not use the EXEC CICS
WEB API commands but produce an HTTP response in a COMMAREA, CICS Web
support is not able to assist with assembling the message structure correctly,
or to carry out its full range of checks on the response. To take advantage
of all the available CICS Web support facilities, it is recommended that
you plan to convert these applications to Web-aware application programs that
use the WEB API commands.
- URIMAP resource definitions can be used to deliver the contents
of a CICS document
or HFS file as a static response, or to deliver a redirection response, without
involving a user-written application program. You could consider using this
mechanism, instead of an application program, for simple responses that do
not involve dynamic processing.
- Check that code page conversion is operating in the most efficient
way. With minor changes to your application, you can take advantage
of new CICS Web
support facilities to:
- Avoid setting up and using a code page conversion table (DFHCNV) for CICS Web
support.
- Allow CICS to
identify and use the Web client's character set for code page conversion,
rather than specifying this yourself.
- Use the local system default (LOCALCCSID system initialization parameter)
to identify the application program's code page, rather than specifying this
yourself.
- Convert to and from the UTF-8 and UTF-16 character sets.