Business
Link Windows servers to mainframes, the Microsoft way
Access mainframe applications from modern desktops, using Host Integration Server
Peer into the back offices of most large companies and you'll probably find at least one mainframe or minicomputer running business-critical applications. Many midsize and smaller companies are in the same position. In many ways, the smaller the company, the harder it is to move away from those mainframes and minis to other solutions. The cost of replacement servers is a factor, but porting applications and data is often a much more formidable barrier to such a transition. That's where Microsoft's Host Integration Server (HIS) comes into the picture.
HIS is a follow-up product to Microsoft's SNA Server. It comprises a wide range of tools and services that gives clients transparent access to data on mainframes, AS/400, Unix, Windows 2000, and Windows NT servers. This means that you can continue to use your back-end servers and applications but provide access to them in new ways, including Web-based interfaces. I'm going to take you on a tour of the components and features of HIS. [Ad]
HIS integrates legacy systems with newer networks
In a nutshell, HIS enables you to integrate legacy host systems with client/server and Web-based information networks. One piece of the HIS integration puzzle is the ability of clients to access data on back-end legacy servers through Windows 2000 and Windows .Net servers, as well as through Windows-based 3270 and 5250 client capabilities included with the product. You can also use other third-party clients to access the servers, even when access is funnelled through HIS servers.
Access isn't limited to just applications and data -- clients can easily access files and printers on the back-end systems, too. HIS is very scalable, supporting up to 30,000 concurrent host sessions per server. It improves reliability with support for Microsoft Message Queue (MSMQ) and Component Object Model (COM+). Support for Microsoft Application Center, Network Load Balancing, and other failover technologies means reliability and high availability for clients.
In addition to facilitating client access through emulation clients, HIS enables you to provide client access through custom applications you develop in-house, including Web-based applications. HIS provides built-in data-access capabilities to retrieve data from SQL Server and DB2, and flat-file data on mainframe, AS/400, Unix, Windows 2000, Windows .Net, and Windows NT servers. HIS also provides drag-and-drop support for IBM's CICS and IMS, enabling your developers to more easily integrate applications that use Microsoft Transaction Server and COM+ with these host services.
HIS also offers some handy security-related features. It lets clients log on simultaneously to Windows domains and back-end host systems with a single sign-on. In addition, HIS allows administrators to map user account information on Windows domains to the user's credentials on the back-end host. This synchronisation can significantly reduce the amount of time needed for account administration. To provide security for remote users, HIS supports virtual private networking, enabling VPN connections between clients and hosts.
Let's take a look at the components of HIS so you can begin to understand how they might fit into your enterprise.
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HIS includes several services, each of which supports connectivity and access in a particular area. These components and services fall into four main categories:
- SNA network connectivity: HIS builds on Microsoft's SNA Server to provide the network services needed to connect Windows 2000 and .Net Servers, and multiplatform clients to mainframe and minicomputer servers. HIS acts as an SNA gateway, performing protocol conversion between client systems and host servers. Using an SNA gateway in this way means you don't need to install or manage SNA protocols on the clients or add services to the host servers to accommodate the clients' network capabilities and protocols.
- Data integration: The data integration components in HIS lets server- and client-based applications access data stored on the host servers. HIS provides access to relational and non-relational data on target host systems through a variety of mechanisms, including ODBC, OLE DB, and COM.
- Application integration: These components provide the link between Web- and Windows-based applications on client systems and applications on the host systems. HIS supports both synchronous and asynchronous transactions.
- HIS management: These components provide the administrative hooks into the components of HIS and include such tools as the Microsoft Management Console (MMC) for managing HIS, command-line management utilities, scripting tools, and Web-based administration tools. These tools give you flexibility in managing HIS directly, from remote stations, or through administration scripts and batch files.
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