Emerging Server Hardware Trends

The following sections document several important server hardware trends that continue forward into the foreseeable future. A profound stratification of server types and capabilities is apparent, to be sure, but growth, investment, and interest in all types and strata appear strong well into the second decade of the 21st century.

Continuing Standalone Server Niches

To date, innumerable standalone devices silently and transparently work on behalf of business managers in ways that were previously only imaginable. Thanks to a healthy dose of embedded technologies, standalone servers crop up in the most unusual places, including satellite-connected retail outlets such as convenience stores and gas stations, electrical power substations, telephone company points of presence, and all kinds of networking devices, including network appliances, network attached storage servers, and so forth.

Typically, data backup servers are standalone devices in the common data center topology. There may also be a demilitarized zone for a given organization's network topology that defines single-purpose servers that provide access to their webserver, domain name services, Telnet and file transfer protocols, and others.

Parallel transaction schemes, redundant storage volumes, and multiway processing have become the modern market trend. With the advent of dual-core processors by AMD and Intel, the power once reserved for only the mightiest of enterprise solutions is now found on the desktop. RAID implementations are regular entries to the latest desktop motherboards. And dual-channel memory is nothing new to the contemporary PC.

Increasing Proliferation of Multiway Blades

Having established a strong foothold at the enterprise level, blade servers have seen a strong uptake as an alternative to the existing standard of rack-mounted servers. Midlevel and high-end deployments continue to leverage the cost-effective benefits of the blade design concept. Because they tend to create easily manageable, more efficient configurations, they lend themselves to a better IT experience.

High-Availability and Reliability Versus Cost and Transaction Speed

Network attached storage (NAS) has become a very viable and popular solution to centralizing organizational data so that it is accessible to all who need (and are authorized) to use it. Simple, pseudo-NAS devices might consist of simple bridging circuits that permit ATA-based drives to be accessible over Ethernet-based technologies. They lack the permissions capabilities and block-level data transfers of true NAS solutions, but they perform in much the same way.

However, sharing large data sets across a shared medium that is rate-limited to 10Mbps (Ethernet) can be time-consuming. Hence the adoption of Gigabit Ethernet (GigE) technologies that intimately couple storage capacity and expedient transmission rates (on the order of 100Mbps). GigE better suits high-demand enterprise environments where time-sensitive applications are at play.

Many Niches for Many Needs

Vendors such as Buffalo, D-Link, and Linksys all market devices known as media center extenders (MCEs) that arbitrate transactions between external storage archives and end-user applications. This allows a person to input video from a multitude of sources (for example, disk drives, coaxial cable, HDTV antennas) and output it to local storage, without the assistance of a dedicated server box. This greatly simplifies the home-networking topology, which doesn't need to be a complicated mess of wires, protocols, and hardware. This class of transaction-based behavior easily typifies the client/server paradigm.

Smaller office environments, such as those at home, might contain print servers, a recent market entry that serves as a single point of access for printer resources for multiple endpoints. These small, single-purpose units relieve the network of the need for a dedicated machine (perhaps a gateway server) to operate full time in order to share a common resource among many users. Also from name-brand network equipment manufacturer Linksys is the Network Storage Link over USB 2.0 (NSLU2), which is a tiny MIPS-based core running Linux that conveniently makes USB-based storage media accessible over common Ethernet cabling.

A data center requires that mission-critical and sometimes customer-related data be backed up to some medium for potential recovery or rollback purposes. Such a data center might deploy a dedicated backup server attached to an uninterruptible power supply (UPS) and tied in to voluminous storage drives for archival purposes. This sort of modularization lends itself well to fault tolerance because a similar multipurpose server performing a myriad of duties, including backups, could wreak havoc in the event of failure. Instead, this provides a single point of failure, so that the network can continue to provide resources to its many end users and devices.

Currently, the market trend is heading toward parallelization. Dual-processor concepts have been alive and well used in the industry. Only recently has the proliferation of doubled-up devices, such as dual-core processors, dual-channel memory, and dual Ethernet, resulted in significant performance gains in contemporary applications. Eventually, more doubling up will be realized when processor core logic is able to arbitrate virtual parallelization, whereby one processor can simultaneously execute two separate operating systems.

From there, you can expect the tide to shift from software-based emulation into hardware-level emulation, relieving the system of unnecessary overhead and freeing up resources for other tasks. The advantages of utilizing this sort of technology are manifold, covering a wide and varied range of capability. As a simple example, a web farm may multiply its installation base by creating virtual servers that run FreeBSD, Linux, and Windows in tandem, without requiring rebooting into multiboot arrangements or deploying any of the various emulation packages for this purpose. Consolidating resources in this way goes a long way toward minimizing downtime and optimizing availability.

In the end, the client/server paradigm will continue to flourish, as will ad hoc peer-to-peer topologies, albeit transparently to the end user. Embedded technology is certainly the field to keep an eye on because right now that's where the most exciting new development occurs. It therefore becomes increasingly less obvious what devices constitute server hardware, as the concept of server hardware begins to blur into an even broader range of possibilities and implementations. The rest of this book concentrates on real hardware, with the greatest emphasis on systems and solutions in active use today.