Wouldn't it be great if you could purchase a system that handled all your desktop and BackOffice applications? Wouldn't it be even greater if that system continued to function despite disk, processor, or memory failures? I'm not describing an IS pipe dream: I'm describing Data General's TermServer-in-a-Box.
TermServer is a unique thin-client server that combines hardware and software components. TermServer combines powerful, cabinet-mounted, high-availability NT systems with Microsoft Windows NT Server 4.0, Terminal Server Edition; Citrix MetaFrame; and the clustering component from NT Server 4.0, Enterprise Edition (NTS/E). This combination of hardware and software creates a comprehensive desktop and BackOffice server farm for thin-client users.
The Windows NT Magazine Lab evaluated TermServer to determine how the hardware and software components work together. The hardware components include a 73" cabinet that houses six AViiON servers and a CLARiiON disk array. The servers connect to an Apex keyboard/video/mouse (KVM) switch mounted inside the cabinet. A keyboard, touch pad, and flat-screen monitor connect to the KVM switch; thus, you can control the servers from one console. This console configuration is cool: You can sit at the console and switch from one server to another with a few keystrokes.
AViiON Server Configurations
The six AViiON servers don't have identical configurations. Each of the top two AViiON servers contains one 300MHz Pentium II processor with 384MB of RAM, 2GB of hard disk space, a four-port 10/100 Megabits per second (Mbps) Ethernet adapter, and two SCSI connections to a CLARiiON disk array. Each of the four remaining AViiON servers contains dual 300MHz Pentium II processors with 512MB of RAM, 4GB of hard disk space, and a one-port 10/100Mbps Ethernet adapter.
Combining Software and Hardware
TermServer's top two AViiON servers run NTS/E and function as a Microsoft cluster. This cluster configuration is suitable for back-end applications (e.g., Exchange Server, SQL Server, other competitive server-side products).
The cluster configuration provides fault tolerance for your crucial server-side applications. (For more information about Microsoft clustering and clustering alternatives, see Mark Smith, "The Future of NT Clustering," June 1998, and Jonathan Cragle, "Clustering Software for Your Network," July 1998.) Although TermServer comes with NTS/E, you can remove the clustering software and install another fault-tolerant solution.
The remaining four AViiON servers in the rack host your front-end applications (e.g., Microsoft Office, Web browsers, Outlook, other desktop applications) and run Terminal Server and MetaFrame. Thus, you can connect to the servers using Microsoft's Remote Desktop Protocol (RDP) or Citrix's Independent Computing Architecture (ICA) protocol. TermServer supports RDP and ICA, so you can connect to TermServer from a desktop PC, Windows terminal, UNIX workstation, Mac computer, handheld computer, laptop, or wireless slate computer.
Balancing the Load 
All the thin-client servers in the device's cabinet run MetaFrame load-balancing software. This software turns the servers inside the box into one load-balanced thin-client server farm. Thus, when you connect to TermServer, MetaFrame determines the servers' processing loads and routes you to an available server. You must have Citrix's ICA protocol and ICA client software to use this feature, but adopting ICA as your protocol of choice has virtually no downside.
TermServer's combination of back-end server clustering and front-end server load balancing appeals to me. This configuration protects you from a variety of losses. If one back-end server fails, the other back-end server takes over. If a front-end server fails, the MetaFrame software rebalances the load, and the functioning front-end servers pick up the slack.
How Many Clients Can One Server Configuration Handle?
In the thin-client market, determining the number of clients a server configuration can handle is an ongoing struggle. The answer to the question "How many clients can one server configuration handle?" depends on the size of the applications the clients run. For example, processor-intensive applications consume processor resources. If you run a lot of these applications on a thin-client server, you consume a large amount of processor resources. Similarly, graphics-intensive applications consume large amounts of network bandwidth in the thin-client/thin-server architecture because the applications send all screen information over the network link. Therefore, the more graphics-intensive applications you run, the more network bandwidth you consume. In effect, your front-end applications' resource requirements determine the number of clients your server configuration can support.
I can make some general statements about client-server ratios. I estimate that one processor can handle as many as 25 thin clients. In theory, the TermServer configuration we tested in the Lab can handle 200 users (i.e., 4 dual-processor servers each handling 50 users). If you run lightweight applications or if your users are casual users, the device might be able to handle as many as 100 users per server.
Made to Order
TermServer is available in different configurations. You can have as many as seven thin-client servers in the cabinet, or you can add processors to the cluster servers. You can also order different memory sizes, CLARiiON disk array sizes, or amounts of hard disk space.
TermServer represents a solution that is both new and old. The combination of hardware and software is innovative, unique, and powerful. I hope this is the start of a major trend of hardware manufacturers teaming up with software manufacturers to create fully integrated business solutions. Despite this newness, I have a sense of déjà vu about TermServer. You wheel this unit into a business or department, and TermServer services the computing needs of hundreds of users. I'm reminded of those pre-Windows days when I installed midrange computers (e.g., AS/400s, Digital VAXs, HP3000s). I'd roll the computer in, plug it in, set up the terminals, and leave. However, unlike the old midrange computers, TermServer can run all Windows-based software. I don't think thin-client computing gets any better than that.
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Contact: Data General * 508-898-5000 or 800-328-2436 Web: http://www.dg.com Price: $95,000 for tested configuration |
