Weighing 4 options to client/server
Blade technology, terminal servers and thin clients are viable choices
- By Wayne Rash
- Oct 17, 2005
Government technology managers know client-server architecture because they deal with it daily, and many of them have the gray hair to prove it. They also know that despite its problems with excessive floor space requirements, heat generation, power consumption and security issues, they can't throw out their servers or desktop computers any time soon.
But that doesn't mean they need to be doomed to sitting in cramped, overheated server rooms using desktop computers that are a black hole for support costs and have frustratingly short life cycles. There are alternatives.
In fact, some agencies are enjoying significant benefits resulting from a move away from traditional client-server technology.
"We're seeing a cost savings of almost $400 per seat," said Jeffery Shiflett, assistant director of information technology for York County, Pa. Shiflett said the county's move to a terminal server environment with thin clients has dramatically improved operations in his department, in one case reducing help-desk calls by 62 percent.
In a terminal server setup, processing occurs on the server, and more economical, scaled-down computers called thin clients can replace traditional desktop PCs.
Other alternatives can also improve efficiency and lower costs. Blade servers, which concentrate multiple servers into one chassis, are allowing government IT shops to streamline system administration and free valuable space.
"What we're seeing is fairly significant interest in blade technology, especially
on the [Defense Department] side," said Bob Pace, a senior consultant on the Hewlett-Packard technology team at reseller GTSI. "Primarily this is to do more with fewer resources."
Another option is blade PCs, in which the hardware for multiple PCs is squeezed into one centrally located box instead of placed on every users' desk.
Managers face a challenge when they start to decide which, if any, of those solutions might work for them. Sometimes a combination is the answer.
The following sections provide an introduction to how these options work. Be aware that these are only examples of what's available and only some of the main issues to weigh, so more homework would be in order for anyone seriously thinking about a move.
At first look, a blade server seems to be simply a way to cram more computers into less space. But there's more to it than that. Reducing the amount of space servers use is valuable to many government IT installations, but blade servers also
offer features like hot-swappable parts, which allow technicians to replace a failed
blade with a new one without disrupting operations.
A blade server consists of a chassis into which you plug multiple single-board computers. You can also plug other types of blades into the chassis, too. For example, some blades support Gigabit Ethernet switches or Fibre Channel storage switches. Storage blades with hard disks are available, too.
Specific configurations within a blade type can also vary. For example, processor blades can come with chips from Intel or Advanced Micro Devices and have one or as many as four processors onboard, depending on users' needs.
The chassis provides central services to the blades. For server blades, that includes electrical power, cooling fans, Gigabit Ethernet interfaces for network connectivity and access to storage. The chassis also comes with connections for keyboards or mice. Because of this consolidation, blade servers use less space than traditional stand-alone servers would to get equivalent processing capacity. Stand-alone servers each provide their own power, network connectivity and related infrastructure.
For example, IBM said its blade server system will allow you to install as many as 84 dual-processor servers in an equipment rack that might otherwise hold only about 42 traditional servers.
On the downside, blade servers are missing basic standards. You cannot use blades designed for a Hewlett-Packard blade server in a chassis built for IBM blades. Third-party manufacturers of switches, storage and other hardware must design their products to fit the interconnect and size requirements of each manufacturer it plans to support.
On the other hand, IT managers can gain great flexibility in size and capacity of the blades, along with many options in processor and operating system support. They can make changes as needed with relatively little impact on their overall environment.
Blade servers are available from numerous server manufacturers, but HP and IBM have the largest shares of the market, analysts say. Earlier this month, HP acquired RLX Technologies, one of the pioneers of the blade market. RLX stopped selling hardware last year in favor of focusing on blade management software.
ClearCube Technology does for PCs what IBM, HP and others do for servers. They put a computer --
in this case the client PC --
on a single board, which then slides into a chassis that provides power, communications and control support. ClearCube fits as many as eight single-board computers into a chassis, which the company calls a cage, that's about the size of a desktop PC.
Each user desktop has a monitor, keyboard and mouse that connect to the blades in the chassis. Users get the functions and flexibility of their own client computers, but the hardware is safe and secure in the IT office.
"You get power savings, space savings and flexibility," said researcher Brian Chee, who runs the University of Hawaii's
Advanced Network Computing Laboratory. Chee said he can place the keyboard, mouse and monitor more than 656 feet away from the ClearCube chassis using a connection device that runs its signals via standard Category 5 network cable. The company also offers a fiber-optic cable option that extends the configuration's range to 1,640 feet.
Chee said he has found that this frees scarce space in an office environment. Administrators can configure the ClearCube chassis so that a pair of blades support multiple workers or multiple blades support one worker, he added.
A number of government agencies use ClearCube's blade PC products. This summer, the U.S. Patent and Trademark Office began exploring the use of blade PC technology to support employees who participate in the agency's work-at-home program.
Traditional client-server applications typically split processing duties between the server and the client computer on the user's desktop. The benefit of this approach is that it takes advantage of the client's processing power, which otherwise might go underused. The disadvantage is that users also like to use their PCs' processing power and often load software on them and change system configurations, which can disrupt work applications. That costs the IT department time and money to correct.
In comparison, a terminal server system handles both the client and server processing tasks on a single central server and then displays the work on bare-bones client computers located on users' desks. This arrangement gives the IT staff much more control over the computing environment. And because the server handles most of the work, client computers don't need to be expensive, high-end machines.
The most important consideration for terminal servers is ensuring that remote sites have enough bandwidth to handle traffic.
Shiflett said that for connecting remote offices, dial-up connections aren't fast enough for the Citrix Systems terminal server system he is using. To ensure connectivity to remote offices, York County uses DSL and cable modem connections.
Users in the county's central offices
have more than adequate bandwidth using the Fast Ethernet network backbone, Shiflett said.
Although other companies make terminal servers, Citrix has the lion's share of the market, analysts say. Citrix's products are designed to work in a variety of environments and support nearly any application or operating system that an agency might be running.
Installation of the Citrix system was not difficult, Shiflett said. "Mostly, it was just installation changes and minor configuration changes. Most developers already had experience with it."
He said that even the custom software code developed by the county IT staff was easy to use with the Citrix system.
You don't have to use thin clients with a terminal server system, but you will miss a lot of cost and management benefits if you don't. Some users will always need a fully featured PC or laptop computer. Those are often people who travel or users who need high-end engineering workstations.
For other users, thin clients will provide nearly all the performance they get with a traditional desktop PC but for less cost and fewer management hassles. Configurations vary, but because thin clients usually rely on a central server to do the processing, they often don't have local storage capabilities, certain data ports and other features. That makes them difficult to tamper with or to use to copy data, which makes them a good choice for administrators concerned about security and data theft.
Thin clients are available from a variety of sources, including long-time terminal maker Wyse Technology, HP, IBM and other major PC makers.
Chances are that many organizations won't leave the familiar traditional client-server world. But more users are changing to alternative platforms every day. For many of them, the result is lower cost, better use of resources and greater efficiency.
Rash is a freelance journalist based in Washington, D.C., who has been covering technology since the late 1970s. He can be reached at firstname.lastname@example.org.