The Access Service Library is the program component of DirectConnect that works with MainframeConnect to provide access to DB2 data. For more information on the Access Service Library, see the Mainframe Connect DirectConnect for z/OS Option User's Guide for DB2 Access Services for your database system.
Earlier releases of RSPs used a processing technique similar to the current processing through Access Service Library. The following figure illustrates RSP processing through Access Service Library.
Figure 1-4: RSP processing through Access Service Library
The following explains each step in Figure 1-4:
The client application requests a remote procedure call (RPC) using one of the following commands:
USE PROCEDURE rspname &VARNAME1=value1 EXECUTE rspname @VARNAME1=value1
In Access Service Library, you invoke an RSP using the
RSP name.
Access Service Library passes the request to DirectConnect.
DirectConnect passes the command, containing the RSP name and any necessary arguments, to MainframeConnect. The request can contain a number of other statements, any of which can also invoke RSPs.
MainframeConnect invokes the RSP through the CICS LINK command. Arguments and other parameters are passed to the RSP using the Stored Procedure Communication Area (SPAREA). For more information on the SPAREA, see “SPAREA”.
The RSP performs the desired processing (for example, accessing DB2 data).
Open ServerConnect packages the data and messages produced by the RSP, and sends them to DirectConnect.
DirectConnect returns results to the client application.
The RSP returns program control to MainframeConnect with a CICS RETURN command
Figure 1-5: Direct RSP processing using TCP/IP
The following explains each step in Figure 1-5:
The client application invokes an RSP using the following command:
USE PROCEDURE rspname &VARNAME1=value1
MainframeConnect invokes the RSP through the CICS LINK command.
Arguments and other parameters are passed to the RSP using the Stored Procedure Communication Area (SPAREA). For more information on the SPAREA, see “SPAREA”.
The RSP performs the desired processing (for example, accessing DB2 data).
Open ServerConnect packages the data and messages produced by the RSP.
Open Server sends the data and messages to the Client Workstation.
The RSP returns program control to MainframeConnect with a CICS RETURN command.
