Installation and Reference Guide ClearConnect 1.3
|Chapter 1: Understanding Enterprise Connect|
This chapter provides an overview of the Enterprise Connect product line, including how ClearConnect relates to other Enterprise Connect products.
This chapter includes the following topics:
Enterprise Connect is a set of Sybase products that provides a common, enterprise-wide architecture that supports the development of distributed computing applications.
Enterprise Connect products provide the following services:
Enterprise Connect refers to the new generation of Sybase middleware, as well as its predecessors. The following table maps Enterprise Connect products to their corresponding predecessors:
MDI Database Gateway
MDI Access Server (RSPs)
MDI Access Server (CSAs)
MainframeConnect for DB2/MVS-CICS
OmniSQL Access Module(TM) for DB2
MDI Access Server (DB2)
This section explains the following products and their components, as well as their predecessor products:
ClearConnect is a Windows-based ODBC (Open Database Connectivity) driver that supports direct client-to-host access to IBM Database 2 (DB2) data.
ClearConnect uses Distributed Relational Database Architecture (DRDA) for connectivity and runs on the client, allowing client applications to connect to any DRDA-enabled DB2. ClearConnect accesses the following data:
With ClearConnect, client applications, such as Powerbuilder, Microsoft Access, and Visual Basic, and other ODBC applications, can directly query and update DB2 databases.
ClearConnect has the following capabilities:
ClearConnect provides a point-to-point solution for project teams and workgroups requiring access to DB2 data. As projects grow and client volume increases, ClearConnect provides an easy migration to a larger-scale solution, such as DirectConnect for DB2/MVS.
Open ClientConnect is a programming environment that lets you create mainframe applications that access LAN data residing on a Sybase SQL Server or any other supported data source. It allows you to treat the mainframe as just another node on a LAN.
Open ClientConnect uses the following APIs:
The following table provides migration information about the Open ClientConnect predecessor products.
Open ClientConnect replaces Open Client/Mainframe.
If you still use Open Client/Mainframe at your site, you cannot customize the code pages; that functionality is available only with Open ClientConnect, releases 3.1 and later.
MDI Access Server
Open ClientConnect replaces MDI Access Server (CSAs).
Open ServerConnect is a programming environment that lets you create mainframe transactions that are accessible to Sybase client applications. To provide this access, Open ServerConnect uses the following basic interfaces:
These transactions provide access to virtually any MVS data source and are used for a variety of functions, including:
LAN-side client applications access Open ServerConnect transactions directly through DirectConnect or indirectly through OmniConnect or a Sybase SQL Server remote procedure call (RPC).
The following table provides migration information about the Open ServerConnect predecessor products.
Open ServerConnect replaces Open Server/Mainframe.
If you still use Open Server/Mainframe at your site, cursor processing is unavailable. Cursor processing is available only with Open ServerConnect, releases 3.1 and later.
MDI Access Server
Open ServerConnect replaces MDI Access Server (RSPs).
DirectConnect is Open Server-based software that supports
DB-Library, CT-Library, and Open Database Connectivity (ODBC) application programming interfaces (APIs).
DirectConnect serves as a fundamental building block for database middleware applications. DirectConnect products are local area network (LAN)-based middleware gateways and servers that provide access to non-Sybase data and applications.
DirectConnect provides the following middleware services for decision support and online transaction processing (OLTP) applications:
The following table provides migration information about the DirectConnect predecessor products.
DirectConnect and its TRS and MCC components replace Net-Gateway and its MSG and MCG components.
Net-Gateway 3.0.1 provides the same functionality as DirectConnect using TRS and MCC, if Open ServerConnect (or Open Server/Mainframe) and Open ClientConnect (or Open Client/Mainframe) reside on the mainframe. Specifically, Net-Gateway 3.0.1 routes requests:
DirectConnect replaces the Database Gateway.
This section explains the components of DirectConnect: Access Services, Transaction Router Service, and Mainframe Client Connect.
An access service is a logical server application, used with an access service library, to which clients connect. Each DirectConnect server can have multiple access services.
For more information about access services and access service libraries, see the DirectCONNECT for DB2/MVS Access Service Guide.
TRS, a component of DirectConnect, is used when the mainframe acts as a server. It routes requests from remote clients to Open ServerConnect transactions. Optionally, it can also route requests to MainframeConnect for DB2 (or OmniSQL Access Module for DB2), and return results to the clients. TRS is a required component if you are using SNA networks.
The following table provides migration information about the TRS predecessor product.
Mainframe Server Gateway (MSG)
DirectConnect and its TRS component replace Net-Gateway and its MSG component.
Net-Gateway 3.0.1 and MSG provide the same functionality as TRS. Specifically, MSG is available to route requests from the LAN using Open ServerConnect (or Open Server/Mainframe) to the mainframe.
MCC, a component of DirectConnect, is used when the mainframe acts as a client. It is a LAN-based program that lets mainframe Open ClientConnect applications connect to LAN servers. It performs data and protocol translation between SNA/LU6.2 (APPC) and TCP/IP with the LAN network protocols. When accessing through SNA networks, MCC is required.
The following table provides migration information about the MCC predecessor products.
Mainframe Client Gateway (MCG)
DirectConnect and its MCC component replace Net-Gateway and its MCG component.
Net-Gateway 3.0.1 and MCG provide the same functionality as MCC. Specifically, MCG is available to route requests from the mainframe using Open ClientConnect (or Open Client/Mainframe) to the LAN.
Database Gateway Access Server
DirectConnect and MCC replace the Database Gateway Access Server.
DirectConnect Configuration Tool is an Open Client-based graphical user interface (GUI) systems management tool for administering data accessible through DirectConnect. DirectConnect Configuration Tool runs only on Windows 3.1, Windows 95, or Windows NT. It provides the following capabilities:
MainframeConnect is mainframe software that works with DirectConnect or Net-Gateway 3.0.1 to provide access to mainframe data. It performs the following functions:
Client applications access MainframeConnect directly through an Access Service or TRS.
Client applications access MainframeConnect indirectly through OmniConnect or a Sybase SQL Server remote procedure call (RPC).
Note: MainframeConnect is available only for MVS-CICS environments. For IMS TM and native MVS environments, use OmniSQL Access Module for DB2 for IMS and MVS.
The following table provides migration information about the MainframeConnect predecessor product
OmniSQL Access Module for DB2 CICS
MainframeConnect for DB2/MVS-CICS replaces OmniSQL Access Module for DB2 CICS. It does not replace OmniSQL Access Module for DB2 for IMS and MVS.
You can use either Net-Gateway MSG 3.0.1 or TRS with MainframeConnect for DB2/MVS-CICS.
MDI Access Server
MainframeConnect for DB2/MVS-CICS replaces
The Enterprise Connect products enable desktop computer and workstation users to communicate with mainframes in a client/server environment. The Enterprise Connect processing environment consists of several hardware and software components, such as the following:
Software from other vendors
Note: Not all these software products are required at your site.
This section lists and briefly explains the related Sybase and IBM products.
Enterprise Connect can be used with most Sybase products to connect mainframe applications with remote clients and servers.
The products in Table 1-8: Related Sybase products are frequently used as clients and/or servers with the Enterprise Connect set.
You need Sybase, IBM, and vendor communications documentation to configure, install, and manage Enterprise Connect products. You may need additional IBM and vendor manuals for your particular configuration. Be sure you have the necessary IBM manuals on hand before you begin to configure TCP, IMS TM or APPC MVS, as well as the Open ClientConnect and Open ServerConnect Messages and Codes guide for your mainframe products.
With SQL Server acting as a server, clients using Open ClientConnect can send requests to a named SQL Server through Mainframe Client Connect.
SQL Server, the Sybase RDBMS, can act as a client or server. Networked clients can call SQL Server stored procedures that send requests to Open ServerConnect or MainframeConnect for DB2 (or OmniSQL Access Module for DB2) on the mainframe. The DirectConnect administrator can configure the TRS to require all client requests to be routed through SQL Server.
OmniConnect translates SQL statements that DB2 cannot read or process into statements that DB2 can process. OmniSQL Access Module for DB2 clients can route requests through OmniConnect for SQL translation. Sites that need to run the same applications without modifications against both SQL Server and DB2 can use OmniConnect as a server.
Open Client is a Sybase connectivity product that provides customer client applications, third-party products, and other Sybase products with the interfaces needed to communicate with Sybase servers and Open Server applications, including Open ServerConnect and OmniSQL Access Module for DB2 and MainframeConnect.
Open Server provides the tools and interfaces needed to create a custom server (called an Open Server application).
Open ServerConnect uses Open Server architecture to allow the mainframe to act as a server.
Open ClientConnect clients can send requests to Open Server applications on the local area network (LAN) through Mainframe Client Connect, or directly through Intersystem Communication (ISC) if requests are being sent to Open ServerConnect in a separate region.
Replication Server keeps copies of data up-to-date at multiple sites so that clients can access local data instead of remote, centralized databases.
Replication Agent is a functional component of the replication model that conveys updates made to primary data sources to a Replication Server.
The Enterprise Connect set uses a number of IBM mainframe software products to allow mainframes to act as clients and servers. The most important of these products are listed in Table 1-9: Related IBM products.
A program-to-program communication protocol.
An application programming language. Open Client Client-Library is available for C.
A transaction monitor on the mainframe.
DB2 (Database 2)
A relational database on the mainframe that uses SQL. Enterprise Connect clients can send requests to DB2.
A transaction monitor and data communication system on the mainframe. Open ServerConnect, Open ClientConnect, and the OmniSQL Access Module for DB2 are all available for IMS(TM) TM.
OS PL/I Version II
An application programming language. Open Client Client-Library and Open Server Gateway-Library are both available for PL/I.
A communication protocol in general use. The following can use TCP/IP to communicate through DirectConnect:
VS COBOL II
An application programming language. Open Client Client-Library and Open Server Gateway-Library are both available for COBOL.
A mainframe access method used with SNA. Mainframe-based Enterprise Connect products run in a VTAM environment.