Distributed Computing: Serve It Up

Servers are the workhorses of networked, distributed computing.

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Servers are the workhorses of networked, distributed computing. In fact, the online encyclopaedia Wikipedia calls the Internet a “forest of servers.” As information technology (IT) professionals adopted client-server architecture during the last 20 years, servers became the key component. In a client-server architecture, clients—usually personal computers, or these days, mobile computing devices—connect when necessary to a remote server in order to perform some sort of work.

The term server can refer to a special-purpose computer that usually contains an array of hard-disk-drive storage. It can also refer to application and operating system software that enables performance. Or, the term can refer to both together, or to special purpose applications. Some of these applications include Web page servers, printer servers and e-mail servers. Most often for manufacturing, servers enable storage and retrieval of vast amounts of data derived from manufacturing operations.

On the hardware side, the market has moved from specialized, more expensive devices to less-expensive boxes derived from the personal computer industry based on the Intel x86 microprocessor architecture. This has enabled use of less expensive operating systems such as the open-source Linux or Microsoft Windows Server.

Windows Server operating system software, for example, enables more than networking connections and access to the data on the hard-drive array. Business drivers today require support of employees and contract staff in remote locations. The latest release of Windows Server is designed to speed up remote tasks such as logging on, access to data and administration of remote computers. It also has built-in tools to assure security and back-up of data. Because a server failure can be catastrophic to business operations, the operating system contains technologies for high availability.

Many manufacturing locations may only have a few servers. Think of the huge data storage and retrieval requirements of even a moderately popular Web site. Then multiply almost exponentially to a company such as online Internet search provider Google Inc., which actually buys huge warehouses to build “server farms” of thousands of these computers. Each computer has a power supply and lots of motors to turn the disk drives. These are consumers of energy and providers of heat. In other words—energy hogs.

Maximize efficiency

Google has implemented policies and technologies designed to reduce the amount of electricity required to operate such huge installations. It calls it a “sustainable infrastructure.” First, it rates the efficiency of servers by measuring the power used by each of the actual computing elements (such as processors and memory) against the power used by all other things (such as fans and power conversion).

Google calculates that up to a third of the total energy consumed by a typical server is wasted before reaching the computing components. The power supply and voltage regulator circuits are primary culprits.  Google uses power supplies that exceed the Climate Saver Computing Initiative’s “Gold” efficiency standards. Similarly, motherboards use very efficient voltage regulator modules, maximizing the amount of electricity delivered to the components that do work. Google says its servers only lose a little more than 15 percent of the electricity input, less than half of what is lost in a typical server. It estimates an annual savings of more than 500 kilowatt hours (kWh) per server over a typical system.

Other Google engineering includes omitting parts that aren’t needed for applications, and optimizing servers and racks to use the minimum amount of fan power possible. Moreover, the fans are controlled to spin only as fast as necessary to keep the server temperature below a threshold. Suppliers are encouraged to produce components that operate efficiently whether they are idle, operating at full capacity or at lower usage levels.

Your server installation may be a candidate for cost reduction as well as performance enhancement.

Gary Mintchell, gmintchell@automationworld.com, is Automation World’s Editor in Chief.

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