Ever since businesses started to network PCs in large numbers they have been aware of one thing: PCs were not designed to be networked in large numbers. The mounting costs of owning PCs sparked a vociferous 'religious war' among IT suppliers over whether to go for fat PC clients or thin client/server-based computing.
That war is now more or less defunct. Windows 2000 includes support for thin clients as standard. All the major PC manufacturers, except Dell, now also supply thin clients. The advent of the Internet has made many applicationsserver-based,whilethe prospect of supporting multiple Wap phones and wireless personal digital assistants (PDAs) further clouds the once-simpledichotomy of thin versus fat.
While suppliers fought and then made up over the thin-client debate, some users have been quietly reaping the benefits. When retail supplier Littlewoods looked at providing PC applications to stores throughout the UK, it saw support issues as being onerous. To avoid having to send a member of the support team hundreds of miles every time a PC broke down, the company optedfor theWindows-basedterminal model - and has never looked back.
"Generally, it's been a big success," says Andy Dawson, infrastructure manager at Littlewoods. "It has delivered everything we expected it to deliver in terms of reduced support overhead. We have not been able to quantify that, but we have managed the environment within our existing team and extended theservice to an extra 300 users."
However, Dawson says there are limitswithhis Citrix-based thin-client
implementation. "We have to be carefulnotto become a victim of our own success," he says. "People often ask us to put another application on the system. We feel it's important to keep within our niche. We have to keep control of the environment - a power user could lock up the resource of a whole server and prevent 20 other users from logging on."
Before Littlewoods implements a new application across its network, the application has to be analysed to ensure it adheres to the Microsoft Terminal Server guidelines, says Dawson. Support staff must also check applications for memory leakage, which can bring down a whole server.
Littlewoods has 350 terminals at stores around the country each available to multiple users. E-mail, Microsoft Word and Excel are offered as standard, while PowerPoint is restricted because it is power hungry. There are also line-of-business applications that are browser based. Littlewoods uses Windows NT 4.0 Terminal ServerEditionandCitrix MetaFrame load balancing software. Although Littlewoods is testing Windows 2000, which includes load balancing for servers supporting thin clients, the company is unlikely to abandon Citrix. "We believe a network manages bandwidth better than Windows Terminal Service," Dawson says.
This is typical of successful Windows-based terminal implementations, according to Eric Grayson, European marketing director at NCD, which manufactures thin-client devices. "The retail market is very big," he says. "So is banking and financial services - often these companies have a history of server-based applications and mainframe environments."
Andy Brown, analyst with IDC, says that with most of the major suppliers now providing thin-clients the model is gaining in popularity, particularly in vertical markets such as banking and finance. However, Brown says that the continuing growth in PC sales shows that the thin-client market will remain relatively small. "Most research has shown that the idea of thin clients being the next big thing never materialised, but they have become a significant niche player."
However, the argument for server-based computing as a means of reducing the massive costs of supporting PCs still remains, according to Mark Margevicius, senior research analyst with the GartnerGroup. He estimates that 40% to 45% of the cost of owning a PC is associated with end users not doing what is right for them or their organisation.
"The thin-client model takes away that variability from the client," he says. "Not only is the total cost of ownership reduced from the end-user point of view, you get to put a cheaper device on the client location."
However, Margevicius points out that companies looking for reduced capital expenditure tend to forget that saving with hardware is limited. What you take off the desktop you have to put on the server - the exact demand on the server and the network will depend on the application.
Another area in which users expect costs to fall is software licensing, he says. "A number of people still think that just because applications are running on the server, licensing costs will go down. In fact, these will remain the same, and there may be additional costs if you chose to license MetaFrame or WinFrame from Citrix."
The licensing model offered by software suppliers varies. While Citrix offers a licensing model based on the maximum number of users that can concurrently access the server application, Microsoft demands a client access licence (CAL) for every user that can access an application and operating environment. This means that users must have a Windows NT Workstation CAL for every thin-client user. Although this is offered as a discount, the workstation operating system is not even in use.
Margevicius says that users may have the ability to negotiate deals with software suppliers such as Oracle or SAP for concurrent licensing. This is not likely to happen if you are dealing with Microsoft software. Windows product manager Mark Tennant confirms that Microsoft licences for business users would remain on a client-access basis, whether the software is served to a thin client, PC or browser-based device.
Although PC sales far outstrip those of thin clients, this does not imply that server-based computing is unpopular. The ability to lock down PCs to prevent end users loading software, together with a dramatic fall in PC prices, has resulted in PCs becoming the most common client-to -view server-based applications.
"PCs are much cheaper than they were when this idea first came about,"Margevicius points out. "The thin clients have ended up costing around £100 less than a PC. You can configure a PC to look like a thin client or to work on its own. PCs are providing users with greater flexibility."
Dell, the only major PC supplier not to offer thin-clients, has no intention of moving into the market. Client systems marketing manger James Griffith says PCs will remain the company's core product for at least the next five years. He believes that PCs offer users flexibility - an option to go with server computing or not - without being locked into particular desktop hardware.
Citrix, the company that originated software to allow multi-user Windows access, estimates that 80% of its installations are running on PCs rather than thin-client terminals.
As a guide, users should check four things before moving to server-based computing says Margevicius. First, can the application be adapted to the server? Most can, but for technical reasons, some cannot. The server and network must have 100% availability - all users stop working when the system crashes. The network must also be pervasive - if it cannot be accessed from some locations, you cannot standardise the model. Lastly, power-hungry and mobile computing is not suited to thin clients.
Margevicius says the thin-client model is most likely to be successfully deployed in pockets within companies, rather than as a company-wide standard. Some organisations are very unlikely to take to it at all.
"Try putting thin clients in a university where there is large number of knowledge workers, who need a lot of flexibility," he says. "It [server-based computing] won't workwithremotesales forces, or field engineers either.Generally,the model does not suit peopledoingindividual,unpredictable work that is unique from one day to the next."
Once users and suppliers free their minds of the thin versus fat debate, it becomes obvious that server-based computing has already taken off in a massive way, says Margevicius. "Really, the ultimate thin model is the Internet, were everything comes through the browser and all you download are applets. People do not think about it like that. This is where the real growth has been and will continue to be.
"Moving forward, this model will continue to grow along with the pervasiveness of networks. New server-based applications will become available on all sorts of devices, including PDAs and cell phones - these will all be thin-clients. Over time there will be many alternative devices to which applications are presented," he adds.
But this also presents a problem. Although the thin-client concept was intended to resolve the horrendous management problems of supporting PC networks, the explosion in the number and variety of client devices accessing Internet applications will create difficulties of its own.
The big problem is going to be synchronising information across these devices, and across disparate server infrastructures. According to Margevicius, "Two client types can be difficult enough, but four or five different clients, that's a problem. The job of synchronisation is going to be horrendous. The IT shop is going to be expected to take control of it and it is going to be a difficult job."
The GartnerGroup's Guide to going thin
Mark Margevicius, senior research analyst with the GartnerGroup, offers four factors to consider when choosing whether to adopt server-based computing or to stick with more conventional PC networks.
Make sure the application behaves properly
Some software never can be configured to network computing applications. Issues such as the addressing of system hardware may be written into the application, for example, accessing disk drives. Rewriting the application may be too complex to consider.
Server and network availability
You need to have 100% availability on your network and server. All of your users are totally dependent on it - if it goes down they cannot work. A couple of years ago Oracle CEO Larry Ellison was demonstrating network computers and suffered an embarrassing outage. For business, it can be more disastrous, so redundancy should be built-in according to business risk.
Users must be able to have access to high-quality network infrastructure throughout your organisation. The cost of upgrading or expanding the network will be a factor in your decision.
Type of usage
If you have a call centre where orders are taken in a single, fixed location , then thin-client s can be a good idea. If you have a travelling salesforce, thin clients are inappropriate. For example, you cannot use a thin-client workstation while flying 30,000-feet above ground.
Thin client vs PC - the story so far
The problems in supporting a PC network are legendary. Although PCs are supposed to be built on an open architecture, the truth is they conceale all sorts of differences in hardware and software, which makes managing large corporate networks a nightmare.
Only in the past few years has distributing software from a central location been possible, meaning IT support staff would not need to take laborious and costly journeys around every company location to give users new applications. In addition, PCs attracted the attention of the end-user enthusiast who could load his or her own software on to systems, adding viruses and instability.
By the mid-1990s, so disgruntled were IT departments at this onerous work, that suppliers who had remained out of the PC business, namely Sun and Oracle, sensed an opportunity. Supported by research company Gartner Group's concept of the total cost of ownership, they launched the concept of the Network Computer - a highly managed thin-client that allows centralised software distribution and could prevent end-user tampering. Most of the processing would be done on the client, but the software environment would be configured and controlled from the server. This vision of a PC alternative received a great deal of attention, but sales were limited.
The main reason was that users had already invested in PC infrastructures and Windows-based applications and were not prepared to rip it all out. Although Java-based NCs are used in some specific line-of-business application, they did not replace PCs. However, the thin-client idea did not die.
In 1993, Citrix shipped WinView, software that would allow multiple users to access Windows running on a server. This was followed by WinFrame that contained technology that Microsoft licensed from Citrix and used in its Windows NT4.0 Terminal Server Edition. Now users don't have to buy a different version of Windows, as the capability to serve applications to multiple clients, whether they are PC or thin client, is built into Windows 2000.
This was first published in March 2000