Application Server Notes for MVS Users

Application Dispatcher is now available for MVS. You cannot download this MVS version from the Web site, but if you are interested in receiving a copy, contact your SAS Software Sales Representative. (Application Dispatcher for MVS can be included with TS460 maintenance.)

The Web Tools Web site and the SAS/IntrNet software CD, Version 1.1 provide complete documentation for using Application Dispatcher. This documentation was originally written for Application Dispatcher running with SAS software, Release 6.12. Some exceptions and additions apply when using the Application Server under MVS. This page discusses the information you need for the Application Server for MVS, Version 1.1.

Application Dispatcher Limitations for MVS

The following features are referred to in SAS/IntrNet software documentation, SAS Web Publishing Tools documentation, and sample code, but they are not available for the MVS release of the Application Server:

• Launch services
• MDDB Report Viewer Application
• JPEG graphics drivers
• IMAGE entries

Setting up the Sample Applications

The Application Dispatcher documentation contains a configuration section that describes how to set up the sample applications. The information in this section applies to the MVS installation with one exception. Since SAS catalogs and flat files cannot reside in the same physical library on MVS, the Xplore sample application is installed under the SAMPLIB program library instead of the SAMPLE library.

To use the Xplore sample with your MVS Application Server, find the sample HTML files that were installed with the Application Broker and edit the xplore.html file. This file references a URL containing this partial string:

     
     _program=sample.websamp.xplore.macro

Edit that URL and change the sample libref to samplib, as shown below:

     _program=samplib.websamp.xplore.macro

Starting the Application Server on MVS

The Application Dispatcher documentation describes how to start the Application Server for UNIX and Windows. Information on how to start the Application Server on MVS is provided below. You can choose one of three ways to start the server: as a started task, in interactive mode, or batch mode. Once the Application Server is started, it can sit idle listening on a socket for an indefinite period of time. Leaving an Application Server running in batch will tie up initiators on your machine and prevent other batch jobs from running. For this reason, we recommend that you run the server as a started task. You may, however, want to run the Application Server in interactive or batch mode while you are setting up or testing the server.

PREFIX.SASINET.CNTL(START) contains JCL code that you can use to run the Application Server in batch mode. An MVS system administrator can modify this JCL so that the Application Server is run as a started task.

If you want to run the Application Server in interactive mode, locate the proper SAS CLIST and run it. During the installation of SAS/IntrNet software you created a special CLIST that invokes SAS with the proper libraries allocated, which makes SAS/IntrNet software available. Once you have started SAS software with this special CLIST you can enter an af command on the SAS command line as shown in the following example (the command is broken onto two lines for readability):

     af c=sashelp.web.appstart.scl port=5001 logwind
        srvroot='PREFIX.sasinet.cntl'

where PREFIX is the prefix data set name you chose during installation. As an alternative to entering this af command on the SAS command line, you can submit it in the program editor by placing it within a dm command as shown in the following example:

     dm "af c=sashelp.web.appstart.scl port=5001 logwind
        srvroot='PREFIX.sasinet.cntl'";

Once you submit this command, the SAS session begins initializing the server and then pauses. When the session pauses, it has begun to listen on the TCP/IP socket for requests from the Application Broker. At this point you can try running a program from your Web browser.

Program Names and Server Control Files

The Application Dispatcher documentation contains a very detailed section titled Creating Dispatcher Applications. This section describes the two required fields that must be passed to the Broker from a Web page: _service and _program. The program field contains either a three- or four-level name such as sample.hello.sas or samplib.websamp.xplore.macro. The first level in the program name is a libref or fileref issued in the server autoexec file (SRVAUTO).

On MVS, _program names that end in .sas are assumed to be members in a partitioned data set that contain SAS code in plain text form. The second level in the program name corresponds to the member name in the partitioned data set. The third level of .sas is simply for compatibility with other platforms where the file names must end with .sas.

Programs with four level names can end with .macro, .scl, or .source. These must be placed in SAS libraries and allocated using a libname statement in the server autoexec file.

When you set up the Application Server, you supplied a parameter SRVROOT= that specifies a partitioned data set. This is referred to in the documentation as the server root or server root directory. This data set contains three plain text members of special importance. These are the server control files and their member names are SRVAUTO, PERMDATA, RESET. The full importance of these files is explained in the Application Dispatcher documentation. Simply remember that if the documentation refers to a server root directory, this is a partitioned data set on MVS.

Special GIF Drivers for Dynamic Output

Release 6.09E of SAS software on MVS contains some GIF graphics drivers. These drivers cannot be used with the Application Server. Special GIF drivers have been supplied with SAS/IntrNet software in PREFIX.SASINET.DEVICES. This SAS library contains a devices catalog and is assigned as libref GDEVICE0 when the Application Server is invoked. From within your Dispatcher programs simply use one of the following device driver names to produce dynamic GIF output.

These device drivers should not be used when writing graphics output directly to disk. Only use them when writing to the dynamic output fileref _grphout. Also, there may be notes in the documentation that the graphics sample applications require Release 6.12 of SAS software. That is only a reference to Windows and UNIX platforms. The graphics samples work under Release 6.09E.

Special Note about Filerefs for Output

All text and HTML output produced by an MVS Dispatcher program should be written to the Web browser using the fileref _webout. All binary data including graphics output should be written to the Web browser using the fileref _grphout. The _webout fileref performs EBCDIC to ASCII translation so that the text data will be properly rendered in an ASCII Web browser.

On ASCII hosts such as UNIX and Windows, the two filerefs of _webout and _grphout are identical. Applying this MVS constraint to your programs allows the same code to run on MVS and other hosts.