Microsoft Puts Host Integration Server 2004 into Beta

by Timothy Prickett Morgan

Microsoft may want to take over the world, but it knows there is no way to easily unseat the umpteen trillions of lines of code that are wrapped around OS/400 and z/OS servers from IBM and their unique implementations of the DB2 relational database. Microsoft has always had a surround-and-conquer attitude with these machines and their applications, and it will be no different with Host Integration Server 2004, which just went into beta.

Well, it will be a little different. With SNA Server, which was Microsoft's first stab at communicating with AS/400 and S/390 mainframes from back in the mid-1990s, all the product really did was allow applications running on AS/400s and mainframes, and using the SNA network protocol, to communicate with networks that used TCP/IP, IPX, NetBEUI, or Banyan Vines (remember these last three?) networks. As SNA Server evolved in the late 1990s, Microsoft added features that would allow Windows applications to extract information from DB2 databases and flat-file database systems, like those used in the System/36s (the great grand daddy of the iSeries) or encapsulated in VSAM files or IMS databases on mainframes. With Host Integration Server 2000, Microsoft improved the scalability of 3270 and 5250 print sessions (up to 15,000 sessions per server), added a new ODBC driver for DB2 databases on AS/400s and mainframes, put in a Distributed Transaction Coordinator that allows two-phase commit of database transactions built from hybrid Windows applications and DB2 databases residing on OS/400 and mainframe servers, and allowed COM objects to read and write to OS/400 and VSAM data queues. There were other improvements to the program that allowed DB2 databases on OS/400 and mainframe servers to be integrated with Microsoft's SQL Server databases running on Windows servers. Host Integration Server 2000 also had links to Microsoft Message Queuing Server that let it hook into IBM's own MQSeries middleware (now called WebSphereMQ).

Microsoft ended support for SNA Server on June 30, and it's hoping that the new features of Host Integration Server 2004 are going to convince a lot of customers using the older software to take a big leap to the latest version. Some of the improvements to the software seem to be aimed at mainframe shops, but there is something for OS/400 shops, too.

Specifically, Microsoft has worked with SNA networking specialists Data Connection to implement the IP-DLC protocol, which is a protocol that is part of the peer-to-peer networking subset of SNA called APPN. Simply put, IP-DLC allows machines running SNA to communicate with each other in a switched mode. This has been done by implementing a standard called High Performance Routing over IP (HPR/IP). The switching method allows simpler network topologies than point-to-point connections between machines.

Microsoft has also added a beefed up Transaction Integrator (the kicker to Distributed Transaction Coordinator from SNA Server) in Host Integration Server 2004, which allows programmers working with Microsoft's .NET Framework for Web services and the VisualStudio.NET development tool that implements it to wrap .NET code around legacy applications. Microsoft says further that Transaction Integrator can be made to make a Windows server with the right collection of middleware look like a peer SNA node, as far as legacy applications are concerned, which means companies that want to migrate applications to OS/400 or mainframe servers can so in a piecemeal fashion. (I am certain this is a lot harder than Microsoft is making it sound.) With Host Integration Server 2004, Microsoft is promising "reliable" two-phase commit over TCP/IP to DB2 "running on most platforms" (which makes you wonder if it was reliable in the past). The company says that the ODBC, OLE DB, and .NET data providers for DB2, OS/400, and mainframes have all been improved. Finally, Host Integration Server 2004 will support Secure Sockets Layer (SSL) and Transport Layer security (TLS).

Microsoft says that Host Integration Server 2004 should be in production by mid-2004. Pricing is unclear, but the current Host Integration Server 2000 costs $2,499 per processor and requires Windows 2000 or Windows 2003.