Thin Clients and Sun's JavaStation
"Thin" is in, and with its svelte desktop profile, Sun's JavaStation network computer is attracting admiring glances from corporate IT managers.
by John JerneyHistory has a habit of repeating itself. Even in the fast-paced, ever-changing world of information technology (IT), good ideas have a way of resurfacing though often with a couple of tweaks.
Just over a decade ago, the essence of corporate computing was defined by a large mainframe or minicomputer churning data in a back room or basement. Users gained access to the programs and data from remote terminals connected directly to this "big iron." In this "ancient" world, "centralized" was in, "control" was paramount, and "flexibility" was little more than just an information services (IS) manager's dream.
Then, in the early 1980s, the personal computer (PC) arrived, and with it an entirely new way of looking at the issue. The rigid control of centralized management was quickly replaced by distributed processing. In the desktop world, programs and data resided on the local machines, which in addition to being faster, smaller, and cheaper, offered the long-desired hope for true flexibility.
Under the new regime, desktop computer users could install their own applications, and departments were free to develop their own programs as required. Computing freedom reached a new peak - but not without a price.
New challenges for IS managers were just around the corner. Controlling the loss of information, whether due to hardware failure or theft, was more difficult. And with individual users adding or removing programs at will, maintaining these unique desktop configurations became a Herculean task. So the cry went out for a better solution.
The evolution of network computing
Client/server provided an elegant solution to the most pressing issues. With important data centrally stored on the server, administrators had a much easier time of archiving and restoring. On the client side, workstations typically relied on a core set applications for accessing the server-based data. The lesson seemed clear: simpler clients require less administration. The "thin" client had arrived.
The buzz surrounding client-server persisted into the early '90s. But as PC prices continued to spiral downward, IT managers found the desktop-centric model hard to resist.
Today, though, many are starting to reconsider this equation. The need to balance cost-of-acquisition against cost-of-ownership is one argument currently being advanced by thin client champions, including Sun Microsystems. Core to this strategy is Sun's recently unveiled Network Computer (NC), the JavaStation. What makes JavaStation different from a PC is that it has no local storage.
Without a hard disk or floppy disk through which information can be maintained locally between sessions, the machine effectively lacks a "personality" that requires administration. JavaStation's approach is to store a user's workspace on the company's intranet, where it is accessible using the same means we would access anything else on the Net - via a URL (Uniform Resource Locator).
Aside from being easier to administer, server-based storage means that any user can work equally effectively from just about any location on the network - locally or remotely. In a work environment where project teams may be built and torn down overnight, it's valuable to have a computing model that supports this type of flexibility. The task of installing new application programs is also made easier, since only a single copy on the server needs to be updated and all users have immediate access.
Exploring the JavaStation environment
Perhaps more interesting is what Java Station doesn't have: no slots for add-in peripherals, no local hard disk, no floppy drive, and no CD-ROM drive. JavaStation users interact with the rest of the world through the network via a built-in HotJava Web browser. Without local storage, even the operating system is downloaded automatically when the user first turns on the device. Similarly, the most recent version of all applications is accessible by clicking on icons within the browser.
At the core of JavaStation is an operating system (JavaOS) that features a layered architecture (consisting of, from the bottom up, a microkernel and memory manager, device drivers, the Java Virtual Machine (JVM), the JavaOS graphics and windowing system, and an application programming interface (API)). The system is also specifically tuned to support Java applications and applets. Users interact with a webtop environment, known as HotJava Views, which integrates e-mail, calendaring, and HTML browsing capabilities.
Even though JavaStation is called a thin client, it packs a fair punch when it comes to processing. The advantage is that the client and the server share some of the duties in completing the processing part of the work.
How does JavaStation differ from the more traditional (and less expensive) X-Terminal workstation? Both are considered thin clients, but the real difference lies in where the processing is accomplished. With an X-Terminal, almost all of the processing takes place on the remote server - not only data calculations but, amazingly, control of simple things such as mouse movements and window manipulations. (In X terminology, the terms "client" and "server" have opposite meanings from the more conventional usage - the powerful back-end server is actually called the "client," while the local X-Terminal or workstation is the "server." Here, however, we'll continue to use these terms in the more conventional manner.)
JavaStation, by contrast, uses a more equitable model for distributing the workload. The local workstation runs the application and is responsible for maintaining the user interface, including the mouse and windows, while the server acts more like a server. The network takes a bigger hit at the beginning, when the application is downloaded to the client, but afterwards the amount of network traffic tends to be lighter, offering the potential of more responsive performance.
The advantages of Java Computing
For offices with a heterogeneous environment of PCs, Macs, and Unix workstations, the cost of developing ever-increasingly complex programs is a critical problem. Java was designed to attack the problem squarely. Since (theoretically) they will run identically on any platform that supports the Java Virtual Machine, application programs need only be developed and debugged once (although they still require testing on each of the platforms before deployment).
With Java Virtual Machines now available for all major platforms - and soon handheld devices as well - this technology may be the ideal system for linking legacy systems with more modern environments. From a security standpoint, Java Computing also helps the IS manager by restricting what goes in and comes out of the machines. Since JavaStation has no local storage, the introduction of new programs (and viruses) into the system is better controlled, and data cannot be removed through the workstation.
Who's adopting JavaStation?
One high-profile convert to JavaStation is the Japan-based investment bank Nomura International, which has announced its intention to replace much of its stock of personal computers with 1,100 Sun JavaStations. For users of the remaining PCs, Nomura will add Java-based graphical interfaces to bring the whole network under one system. Nomura expects not only to save money over the two years it will take to implement this, but also to lighten the company's application development crunch.
"JavaStations are cheaper to operate than PCs," notes Geoff Doubleday, managing director of Nomura International's Information Systems Division. "Also, by writing our applications in Java, we get huge portability benefits because the apps will run on any platform we choose."
In the United States, CSX Corp., a global freight transporter, has recently added JavaStations to its corporate computing environment. The company ships goods around the world via ocean liner and over 49,000 km of railroad track. Until now, it has relied on a system called the "transportation workstation" (TWS). Written for OS/2, the application enables clients to place and track shipping orders interactively and online. The reliance on OS/2, however, restricts the range of platforms on which TWS can run. Java provides a way out.
CSX's new system, dubbed TWSNet, is a JavaStation-based solution. It works not only with the device's built-in HotJava browser, but also with any Java-enabled browser on a PC located internally or at a customer's site. CSX estimates that it will save in excess of $5 million annually by reducing its administrative and development costs, while at the same time offering better cross-platform support.
British Telecom (BT) has also discovered the benefits of a platform-neutral environment. The UK-based company is testing a Java-based version of its already successful ServiceView application, designed to provide customers with a direct means for ordering network service, reviewing billing information, and overseeing their communication configuration. Under the plan, BT envisions deploying a thin client ServiceView applet to be run on JavaStations residing at the company's largest commercial customers.
Midsize clients will have access to the applet using their existing PC platforms running a Java-enabled browser. Since BT serves over one million clients falling into these categories, the potential for administrative savings is obvious. From the customer's point of view, direct electronic access to BT translates into faster and more efficient service.
The JavaStation question
While the price of PCs has continued to drop, the cost of administering and maintaining the systems has not. Java computing provides an alternative to PC- and mainframe-based systems, yet allows the enterprise to leverage its existing investment in an established infrastructure.
Since JavaStations enable users to always work with the most recent version of an application, the system offers a workable solution for specialized corporate applications, especially those designed and developed in-house and requiring updating on a regular basis. The system is also well suited for groupware applications because of its clear advantage of storing information in a centralized location, thus enabling all authorized users to have equal access.
On the flip side, while early adopters are reporting that their workstation administration duties have indeed been reduced, much of their attention has refocused on maintaining the network itself. IS managers have expressed concern that a network-centric approach means any serious failure in the communication link affects all users. Likewise, a failure among any of the key servers can have an impact across the entire organization. Careful planning with several points of redundancy is an essential component of successful network computing.
IS managers are also raising alarms about how network computers fit with their existing network management tools. Most vendors have promised to offer better NC client integration as part of their thin client strategy, but as yet few have delivered comprehensive solutions.
Still, Sun claims to have momentum on its side. In a May 1996 survey of US Fortune 1000 companies (conducted by Forrester Research), 62% stated that they have already begun using Java for some development, and 42% anticipate Java will play a strategic role in their company within a year.
It is not clear, though, whether the NC model is best for conventional productivity applications, such as spreadsheets and word processors. Microsoft, perhaps the most vocal proponent of the current PC architecture, warns that most current applications will place an excessive load on the network, reducing the productivity of everyone independent of what application they are running.
nbsp; Still, not wanting to be caught on the wrong side, Microsoft has decided to keep a foot in each camp. The upcoming Windows NT 5.0 is expected to be available in a "thin" version that will store the operating system's configuration files and DLLs (Dynamic Link Libraries) on a central server. Part of Microsoft's Zero Administration Initiative, this will not make NT a true thin client, but it may alleviate many of the issues related to incompatible libraries.
There is still the question of portability, however. While a properly written Java program should run identically on different platforms, current implementations of the required underlying Java Virtual Machine are far from perfect. Simple graphic operations on a PC, for example, will function differently on a Mac. And each PC-based browser comes with its own implementation of the JVM, making the issue just a bit more cloudy.
Notwithstanding these and other concerns, it appears that thin is definitely in. And JavaStation is positioned to take advantage of the move.
John Jerney (email@example.com) is coauthor of three books on local area networks and network management. He is currently editor of mobilis (a monthly Web magazine about mobile computing and communications; see http://www.volksware.com/mobilis) and editor of the industry newsletter Pen-Based Computing: The Journal of Stylus Systems.
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