DirectConnect Server Administration Guide
|Chapter 1: Introduction|
DirectConnect is a Sybase product set that provides basic connectivity to non-Sybase data sources. In particular, it provides access management, copy management, and remote systems management.
This chapter covers the following topics:
EnterpriseConnect(TM) products provide a common, enterprise-wide architecture that supports the development of distributed computing applications. EnterpriseConnect products provide the following middleware services:
Following are brief descriptions of the EnterpriseConnect components.
DirectConnect products are LAN-based middleware servers that provide access to non-Sybase data sources. DirectConnect is Open Server(TM)-based software that supports DB-Library(TM), CT-Library, and Open Database Connectivity (ODBC) application program interfaces (APIs). It serves as a fundamental building block for database middleware applications.
DirectConnect provides the following middleware services for decision support and Online Transaction Processing (OLTP) applications:
MainframeConnect is mainframe software that works with DirectConnect to provide access to mainframe data. It performs the following functions:
Clients access MainframeConnect directly through a DirectConnect Access Service or a DirectConnect Transaction Router Service, or indirectly through OmniConnect(TM) or a Sybase SQL Server(TM) remote procedure call (RPC).
Open ServerConnect(TM) is a programming environment that lets customers create mainframe transactions that are accessible to Sybase clients via DirectConnect. 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:
Clients access Open ServerConnect transactions directly through DirectConnect or indirectly by OmniConnect or a Sybase SQL Server RPC.
Open ClientConnect(TM) allows customers to create mainframe applications that access LAN data in a Sybase SQL Server or any other supported data source. Open ClientConnect uses the following APIs:
Open ClientConnect allows customers to treat the mainframe as just another node on a network. Open Client applications provide referential integrity between mainframe and LAN data, initiating bulk data movements, for example, as part of nightly batch operations.
DirectConnect Configuration Tool is an Open Client-based graphical user interface (GUI) systems management product for administering data. It provides the following capabilities:
Mainframe Client Connect is a LAN-based program that allows Open ClientConnect mainframe applications to connect to LAN servers. It performs data and protocol translation between APPC LU6.2 or TCP/IP and the LAN network protocols.
Mainframe Client Connect replaces the following former products:
DirectConnect consists of a DirectConnect Server, service libraries, and services.
The DirectConnect Server routes incoming client requests and provides a set of support functions that includes logging, tracing, and message handling. You can use it to add and delete services, configure service properties, and manage other features.
The server is designed to operate with a variety of related products, including:
Each DirectConnect service library provides a specific function. The server provides the framework within which the service libraries operate.
A service library is defined by:
Many named service libraries are available through DirectConnect, including the following:
Each access service library supports a common set of features, so that all applications using the features work consistently, regardless of the target database system. For information about access service libraries, see the appropriate DirectConnect Access Service Guide for your database management system.
The product associated with this service library is the DirectConnect Configuration Tool. For information about the administrative service library, see the DirectConnect Configuration Tool User's Guide for Microsoft Windows, Windows NT, and Windows 95.
A service is the pairing of a service library and a set of specific configuration properties. Within each service library is a collection of configuration sets containing properties that define how each service behaves.
The following rules define the relationship between service libraries and services:
You can configure DirectConnect properties on the server level, the service library level, or on an individual service level. To help you do this, DirectConnect configuration properties are grouped as follows:
When you install a DirectConnect Server, the default configurations allow the server to run. Typically you have to configure some properties that define the connectivity to your target database management system. For information on configuring the DirectConnect Server, see Chapter 3, "Configuring the Server."
You can enable and disable services through configuration. A service must be enabled before you can use it. For information on configuring service libraries and services, including instructions on creating new services, see the appropriate DirectConnect Access Service Guide for your database management system.
You can configure properties with a text editor or with DirectConnect Configuration Tool. Changes that you make with a text editor do not take effect until you restart the server, while most changes that you make with DirectConnect Configuration Tool take effect immediately. For more information, see the DirectConnect Configuration Tool User's Guide for Microsoft Windows, Windows NT, and Windows 95.
The DirectConnect Server routes each client request for a service to the appropriate service library. The routing process takes one of two forms:
For information on service name redirection and examples of how it works, see Chapter 4, "Using Service Name Redirection."
The DirectConnect Server manages external files that reside in various subdirectories. For information on the DirectConnect directory structure for your installed platform, see the appropriate DirectConnect Installation Guide for your database management system and platform.
Following are brief descriptions of the server-managed external files:
The server configuration file server.cfg contains all server configuration information. It resides in the cfg subdirectory for the server.
For more information on server configuration, refer to Chapter 3, "Configuring the Server."
One executable file is required for each service library. The DirectConnect Server identifies the library by the file name. To install, load, or access a library, make sure that the executable file for that library exists in the server svclib subdirectory.
Each service library has a configuration collection. This file contains information for the service library and all of its services. The server defines the file format, but each configuration property is defined by the service library, regardless of whether the property is managed at the service library or the service level. The configuration files reside in the cfg subdirectory for the server.
For information on configuring service library properties, see the appropriate DirectConnect Access Service Guide for your database management system.
The service name redirection file snrf.tbl is an optional file that contains all information necessary to redirect incoming service names to other services. The file resides in the server cfg subdirectory.
For information on service name redirection, see Chapter 4, "Using Service Name Redirection."
The log file contains operational information that you can use to correct problems. This is the only active log file for the system. Although the file is maintained in U.S. English, any logged client messages appear in the client language. The log file resides in the server log subdirectory.
For logging information, see Chapter 5, "Log and Trace Files."
The trace file provides debugging information for Sybase personnel. This file is the only active trace file for the system. You can turn it on and off through server configuration. Although the trace file is maintained in U.S. English, any logged client messages appear in the client language. The trace file resides in the log subdirectory.
For tracing information, see Chapter 5, "Log and Trace Files."