Distributed Computing Study Guide
Distributed Computing Study Guide

Distributed Computing Study Guide

Source: University of Minnesota Libraries

Student Price: FREE

An information systems study guide from the University of Minnesota.

Distributed Computing - Study Guide

Client-server computing is a method of distributed computing where one program (a client) makes a request to be fulfilled by another program (a server).

Server is a tricky term and is sometimes used to refer to hardware. While server-class hardware refers to more powerful computers designed to support multiple users, just about any PC or notebook can be configured to run server software. 

Web servers serve up Web sites and can perform some scripting. Most firms serve complex business logic from an application server. Isolating a system’s logic in three or more layers (presentation or user interface, business logic, and database) can allow a firm flexibility in maintenance, reusability, and in handling upgrades.

Web services allow different applications to communicate with one another. APIs define the method to call a Web service (e.g., to get it to do something), and the kind of response the calling program can expect back. Web services make it easier to link applications as distributed systems, and can make it easier for firms to link their systems across organizations.

Popular messaging standards include EDI (older) and XML. Sending messages between machines instead of physical documents can speed processes, drastically cut the cost of transactions, and reduce errors.

Distributed computing can yield enormous efficiencies in speed, error reduction, and cost savings and can create entirely new ways of doing business. When computers can communicate with each other (instead of people), this often results in fewer errors, time savings, cost reductions, and can even create whole new ways of doing business.

Web services, APIs, and open standards not only transform businesses, they can create entire new firms that change how we get things done.

​Case Study - Rearden Commerce: A Business Built on Web Services

Web services, APIs, and open standards not only transform businesses, they can create entire new firms that change how we get things done. For a look at the mashed-up, integrated, hyperautomated possibilities that Web services make possible, check out Rearden Commerce, a Foster City, California, firm that is using this technology to become what AMR’s Chief Research Office referred to as “Travelocity on Steroids.”

Using Rearden, firms can offer their busy employees a sort of Web-based concierge/personal assistant. Rearden offers firms a one-stop shop where employees can not only make the flight, car, and hotel bookings they might do from a travel agent, they can also book dinner reservations, sports and theatre tickets, and arrange for business services like conference calls and package shipping. Rearden doesn’t supply the goods and services it sells. Instead it acts as the middleman between transactions. A set of open APIs to its Web services allows Rearden’s one hundred and sixty thousand suppliers to send product and service data to Rearden, and to receive booking and sales data from the site.

In this ultimate business mashup, a mobile Rearden user could use her phone to book a flight into a client city, see restaurants within a certain distance of her client’s office, have these locations pop up on a Google map, have listings accompanied by Zagat ratings and cuisine type, book restaurant reservations through Open Table, arrange for a car and driver to meet her at her client’s office at a specific time, and sync up these reservations with her firm’s corporate calendaring systems. If something unexpected comes up, like a flight delay, Rearden will be sure she gets the message. The system will keep track of any cancelled reservation credits, and also records travel reward programs, so Rearden can be used to spend those points in the future.

In order to pull off this effort, the Rearden maestros are not only skilled at technical orchestration, but also in coordinating customer and supplier requirements. As TechCrunch’s Erick Schonfeld put it, “The hard part is not only the technology—which is all about integrating an unruly mess of APIs and Web services—[it also involves] signing commercially binding service level agreements with [now over 160,000] merchants across the world.” For its efforts, Rearden gets to keep between 6 percent and 25 percent of every nontravel dollar spent, depending on the service. The firm also makes money from subscriptions, and distribution deals.

The firm’s first customers were large businesses and included ConAgra, GlaxoSmithKline, and Motorola. Rearden’s customers can configure the system around special parameters unique to each firm: to favor a specific airline, benefit from a corporate discount, or to restrict some offerings for approved employees only. Rearden investors include JPMorgan Chase and American Express—both of whom offer Rearden to their employees and customers. Even before the consumer version was available, Rearden had over four thousand corporate customers and two million total users, a user base larger than better-known firms like Salesforce.com (Arrington, 2007; Schonfeld, 2008; Arrington, 2009). For all the pizzazz we recognize that, as a start-up, the future of Rearden Commerce remains uncertain; however, the firm’s effective use of Web services illustrates the business possibilities as technologies allow firms to connect with greater ease and efficiency.

Discussion Questions


​Differentiate the term “server” used in a hardware context, from “server” used in a software context.


Describe the “client-server” model of distributed computing. What products that you use would classify as leveraging client-server computing?


List the advantages that Web services have brought to Amazon.


How has Southwest Airlines utilized Web services to its competitive advantage?


What is Rearden Commerce and which technologies does it employ? Describe Rearden Technology’s revenue model. Who were Rearden Technology’s first customers? Who were among their first investors?


What are the security risks associated with connectivity, the Internet, and distributed processing?

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