views updated Jun 08 2018


While the word "scalability" refers generally to the ability to increase the size of any system in a linear manner without changing its fundamental properties, in the Internet environment and, more broadly in the world of networked computers, the word has come to refer to the ability to grow a network or Web site at the same rate at which use of the system is growing. Peter Loshin and his co-authors, writing in their book, Electronic Commerce, define scalability as follow: "The ability of a system with multiple available processors to call as many of those processors into service as necessary when system load increases, as well as the ability of that system to be expanded." Since all of the work on a Web site must be performed by central processing units (CPUs), the number of those processors and the manner in which they are linked is central to the concept. Loshin et al. link the concept to "performance," which they define, citing others, as "the ability to effectively increase throughput as needed on a single CPU in response to increased systems load." Performance is often an important aspect of adding users to a network.

Scalability became a central concern in the dot-com industry because popular Web sites can exhibit explosive growth. If they are poorly designed or difficult to scale up (because they slow down substantially as more nodes are added) demand is difficult to satisfy and traffic will decline.

While specialized software exists for those who want to attempt scalability projects on their own, many firms offer this service and help businesses design their sites to become efficient models of scalability. These firms are experts in the latest technological innovations and specialize in tiered Internet architecture that allows the site to grow without having to rewrite mainframe systems, while at the same time making better use of existing servers. They also help larger sites set up subdirectories within the domain directory to help serve a large number of accounts simultaneously. By performing these functions, scalability experts can help prevent Web site crashes and save the company lost revenue and damaged reputations.

The inability for an e-commerce site to scale properly could cripple their business. As Nicholas G. Carr stated in an article that appeared in The Standard: "On the Internet, if you can't scaleif you can't get really big really fastyou're nowhere. And it's not enough for just your technology to be scalable. Your entire business model has to have scalability, as well; you need to be able to quickly extend your business into new markets, either horizontally or vertically. 'Will it scale?' is one of the first questions venture capitalists ask."

While scalability is a critical issue for dot-coms, the actual advantage that comes with growing up to become a large Web site can still be debated. A larger site can appear to be more of a threat to a possible competitor that is thinking about entering the market, so much so that small sites are being bought up by larger sites in an effort cut down on the competition. This sort of consolidation can get pretty expensive, and presents a whole new set of scalability issues for the company that is doing the consolidating. Many dot-coms have learned the hard way about the problems that come with rapid and immense growth. A lot of the time, it is the consumer that gets hurt the most.

Carr sums it up by stating: "While scalability will continue to be critical for e-businesses, I doubt scale itself will provide much of an advantage. Companies will need to be able to expand their businesses fast, but their bigness won't ensure lasting success. Rather, once they've scaled up in one market, they'll need to immediately look for new markets in which to replicate their growth. Defense was the name of the game in the old economy. In the new one, offense is everything."

see also Web Site Design


Carr, Nicholas G. "The Myth of Scalability." The Standard. 10 January 2000.

Killelea, Patrick. Web Performance Tuning. O'Reilly, 2002.

Loshin, Peter, John Vacca, and Paul Murphy. Electronic Commerce. Charles River Media, 2004.

                                 Hillstrom, Northern Lights

                                   updated by Magee, ECDI


views updated May 11 2018


Most average computer users have worked with word processing software applications that allowed them to select lines or blocks of text and increase or decrease the text's type size. This action is a very basic example of scalability, whereby the size of something can be changed (increased or decreased) according to need. In the case of e-commerce, the term scalability usually corresponds to the hardware, software, and network infrastructures used to keep Web sites and related systems up and running. Having scalable systems and applications is important for companies because it means that valuable resources and investments won't be lost when it is necessary to make changes to them.

From a technological standpoint, scalability can involve very simple actions like adding memory to a PC or server (computers used to host Web sites), increasing the number of nodes on a computer network, or adding new or more sophisticated features to an e-commerce Web site. However, it often involves a company's entire e-commerce architecture, which consists of many different technology elements. During e-commerce, companies rely on databases to store and present information about products (including prices, sizes, colors, and options), customers (including names, addresses, preferences, and credit card numbers), content that appears on dynamic Web pages, and more. Servers are another important piece of the puzzle. Finally, networks of workstation computers for staff, connected by miles of cabling and network hardware components, also play central roles. In an ideal world, it would be possible for a company to add, replace, or take away different pieces from this constellation without negatively impacting the entire system.

Unfortunately, such is not always the case. When companies find themselves in a position to grow, there are often hurdles that must be overcome first. Among these hurdles are old "legacy" systems that are still very important to the company's operations, but which were not designed for e-commerce. Although there are ways to connect legacy systems to e-commerce software, high volumes of transactions can present problems. Rather than establishing individual patches for many legacy systems, one possible solution to a challenge like this would be to replicate essential data from all legacy systems involved in e-commerce and place it into a special database called a data warehouse, which is compatible with the Web and e-commerce. This warehouse could then be scaled more easily, depending on the company's needs.

Two keys to scalability are size and replication. For example, a software application can be divided into different smaller sections or tiers, each corresponding to a different function or area of e-commerce. One tier might be devoted to a program's user interface while another deals exclusively with the data being accessed. Computerworld explained that successful e-commerce applications keep these tiers separated and require little interaction between them. This allows each layer to be more easily modified without affecting other system areas. If necessary, more memory or processing power can be devoted to one level of an application, but not to others. Replication also is key. When companies create a component for one area of their e-commerce operation, such as programming instructions that deal with accepting special promotional discounts, a good strategy is to then re-use this code in other applications or areas of the site, rather than re-creating it from scratch every time.

Besides technology, human systems can also be rendered scalable. Because the e-commerce business environment is dynamic and unpredictable, it requires e-companies to respond quickly to factors like volatile stock market conditions, pressure from investors and customers, new technologies, and competitive forces. A workforce that is truly scalable is one where many employees work remotely, instead of in the same physical location. Armed with laptops and telecommunications capabilities, such a workforce is able to grow (or shrink) as needed with less regard for other factors. Unlike companies where everyone works at the same physical location, the size requirements of buildings cease to be an issue in this scenario.

Rather than investing heavily in their own e-commerce systems, many companies opted to out-source different functions in the early 2000s. Application service providers (ASPs) were an attractive option. These third parties provided software applications on their own equipment and then charged customers for using it. As part of the arrangement, they assumed the responsibilities and risks involved. This was a cost-effective option for companies that needed to increase or decrease in size very quickly. In this scenario, the ASP makes the hardware and software investments, and the company is able to pay only for what it uses. One trend was that e-commerce software packages began including many essential e-commerce components, such as application servers, Web servers, and middleware (which allows different systems to communicate with one another). Along with choosing ASPs, more companies also were turning to third parties for Web site hosting. Although this did not decrease the need for scalability, Jupiter Media Metrix found that many executives underestimated scalability's importance. By doing so, they increased their chances of future problems, as well as additional costs.


Desal, Gautam; Eric Sanchez, and Joe Fenner. "App Servers Meet E-commerce." InformationWeek, February 26, 2001.

Kurnit, Scott. "Scalability: Are You Fast Enough?" Chief Executive, February 2001.

Saliba, Clare. "Report: E-Biz Neglects External Web Hosting Options." E-Commerce Times, August 15, 2001. Available from

SEE ALSO: Outsourcing


views updated May 17 2018

scalability The ability for something designed to operate at one measure of size to operate successfully at other sizes. The term is commonly used in relation to the development of shared computer applications that are intended to be used by large numbers of users. Of necessity, developments take place with a small number of test users. Unless the application is carefully designed to take account of the interactions that will arise when it is called on to service a large number of users, it may well fail to operate at all, or to operate only with an unacceptable level of service. An application that successfully expands its numbers of supported users is said to be scalable.