Upgrading from a Previous Version

The Version 8 Application Dispatcher has changed greatly from previous versions. While most applications developed for previous versions will not require changes to run under Version 8, there are significant changes to the set up and administration of the Application Dispatcher. The following sections describe issues you may need to consider when you upgrade an existing installation.

Upgrading an Existing Service

Existing Application Dispatcher services can either be upgraded to Version 8 or left at an earlier version. Follow the steps below to upgrade an existing service to Version 8. Note that both the SAS command and the submitted SAS statements have changed with Version 8. Do not attempt to start a Version 8 Application Server with command line options or submitted statements from a previous version. See the Multiple SAS System Versions section below if you want to keep a service at a previous version.

Use the configuration utility (inetcfg) to create a Version 8 Application Dispatcher service with the same name as your existing service. This utility will create a standard service definition without any customizations you may have added in your existing installation.
Convert any LIBNAME or FILENAME statements in your Version 6 or Version 7 permdata.sas file to the corresponding ALLOCATE LIBRARY or ALLOCATE FILE statements in the appstart.sas file created by the inetcfg utility. You will also need to add each of these librefs to the DATALIBS statement in the appstart.sas file. This will make the librefs available globally to all requests executed by the Application Server.
Convert any LIBNAME or FILENAME statements in your existing srvauto.sas file to corresponding ALLOCATE LIBRARY or ALLOCATE FILE statements in the appstart.sas file created by the inetcfg utility. You will also need to add each of these librefs to the PROGLIBS statement in the appstart.sas file. This will allow programs residing in the librefs or filerefs to be executed by the Application Server.
LIBNAME statements in srvauto.sas should be converted to ALLOCATE LIBRARY statements if the library contains SAS catalog entries to be executed. LIBNAME statements should be converted to ALLOCATE FILE statements if the library contains .sas files to be executed. For example, if your srvauto.sas file contains
```
   LIBNAME  MYLIB  'C:\webapp\mypgms';
```
and the C:\webapp\mypgms directory contains both SAS catalogs and .sas files, your appstart.sas file should contain the following statements:
```
   ALLOCATE LIBRARY MYLIB 'C:\webapp\mypgms';
   ALLOCATE FILE MYLIB 'C:\webapp\mypgms';
   PROGLIBS MYLIB;
```
Statements other than LIBNAME and FILENAME statements in your srvauto.sas file must generally be moved to a request init program. See the REQUEST statement for more information on request init programs.
If you have modified your reset.sas file, you may need to create a request init program for your Version 8 Application Server. Move any modified code from reset.sas to the request init program. See the REQUEST statement for more information on request init programs.
Check the service definition in your broker.cfg file on your Web server. Compare it with the Version 8 template broker.cfg to see if any changes are necessary. Generally no changes are required for socket services. There are significant changes to the configuration parameters for launch services. Read the template file carefully for more information.

Running Existing Programs

Existing Version 6 or Version 7 programs will run on the Version 8 Application Server without modifications in most cases.

Existing program libraries and files can be read by the Version 8 Application Server with no modification.
Note: Version 6 libraries can be read but not written by Version 8 of the SAS System. If you want to make changes to your program catalogs in Version 8, you must convert the catalog to Version 8 format using PROC COPY, PROC CPORT/CIMPORT or the Explorer interface. Once you convert the catalog to Version 8, you will no longer be able access this catalog from a Version 6 system.
In Version 6 or 7, SCL programs could preserve state from one request to another in SCL lists. The SCL lists remained in the server after a request completed and could be accessed by any future request. This approach was not recommended because the SCL lists were never cleaned up except at server shutdown or by explicit program code. The SCL lists were shared across all programs in a server with no access control and could not be shared between multiple servers in a service.
Version 8 Application Server no longer allows this practice. Any SCL lists created by an SCL program are deleted when the program completes. SCL lists can be explicitly saved to a catalog or file with the savelist function (and retrieved with fillist). The session feature is a convenient way to persist SCL lists across multiple requests. The lists can be saved to a catalog in the session SAVE library and retrieved by future requests sharing the same session.

Multiple SAS System Versions

The Version 8 Application Dispatcher is compatible with existing Version 6 or Version 7 Application Servers. However, you must install the Version 8 CGI Tools package on your Web server to use the Version 8 Application Server.

The Version 8 Application Broker will communicate with previous versions of the Application Server. You must add a ServiceCompatability: 1.0 directive to the service definition in the broker.cfg file. See the template broker.cfg for more information about this directive.
Load Manager is supported only for Version 7 or Version 8 Application Servers.
Pool Services are supported only for Version 8 Application Servers.
SCL programs must be edited and compiled on a Version 6 system if you want to run them on both Version 6 and later Application Servers. Once a catalog containing Application Server programs is converted to Version 8 format, it is not longer accessible by a Version 6 Application Server.