Headhunter.net: Technical Case

Cluster Mongers
Like any fast-growing e-Business, Headhunter.net must work hard not to become a victim of its own success. Job seekers are an impatient lot, and with so many competing sites on the Web, Headhunter.net focused on building an infrastructure that can scale fast to meet unpredictable spikes in demand.

From the very beginning, the company standardized on Intel® Architecture-based servers. The Headhunter.net site is powered by 2-way Intel® Pentium® III and 4-way Intel® Pentium® III Xeon" processor-based servers distributed and clustered among three server farms. Back-end database management tasksincluding access to the vast database of online job listings and resumesare handled by 4-way Pentium III Xeon processor-based servers running Microsoft SQL Server*. Over 50 Intel Architecture-based servers power the Headhunter.net service.

	"We've learned to pay attention to our load-balancing practices. We've got them down to a science, so we never bring one machine or one server farm to its knees." Mark Fouraker, Vice President of Operations, Headhunter.net

To ensure site responsiveness and uptime, Headhunter.net employs Radware's WSD-NP load-balancing solution to shift processing among the company's three server farms. WSD-NP includes proximity-based geographic redirection, enabling the company to optimize traffic among servers over the Internet. The load-balancing features break large tasks into steps and ship the sections to different servers, resulting in improved performance. The system enables Headhunter.net to even out loads between Virginia, Georgia and California servers. "We've learned to pay attention to our load-balancing practices. We've got them down to a science, so we never bring one machine or one server farm to its knees," says Mark Fouraker, vice president of Operations, Headhunter.net. To help plan for added capacity, Headhunter.net uses Windows NT's performance monitoring capabilities to measure each server's performance.

First Mover Advantage
While Headhunter.net has been able to cluster its servers to keep pace with growth, Fouraker credits Intel Architecture-based servers for helping drive the company's success. The ability to deploy leading-edge software and flexible hardware, for example, enabled Headhunter.net to bend its infrastructure to taskeven as those tasks changed.

"New software gets there first on the Intel Architecture," says Fouraker. "We follow our vendors, and we push them too. New development tools, new testing tools, it's all out there. It gets there first on Intel Architecture. It's a good world for us to be in right now."

Fouraker has found that using Intel Architecture-based servers enables Headhunter.net to find skilled people even in today's tight IT market. The result: The company can quickly develop and deploy solutions to meet market demand. That advantage is further enhanced by the thriving marketplace for Intel®-based server products.

"The last servers we ordered were delivered in six to nine days. We'd never have gotten such immediate response in the RISC world, where you have to go through a middleman," says Fouraker. "That is a bottleneck that I don't want to deal with and, in the Intel world, I don't have to."

Built to Scale
Perhaps most important, Intel® processor-based servers have allowed Headhunter.net to scale our operations to meet demand. Currently, the company adds a new 4-way Intel Pentium III Xeon processor-based server at the rate of about one per week. At the same time, Headhunter.net has been scaling up, moving from dual- processor servers to powerful quad-processor models as its needs grow.

Fouraker says his operations grew rapidly from a single dual-processor server to a quartet of 2-way servers. Soon, the company was running a farm of two dozen 4-way and fifteen 2-way servers based on Intel Pentium III Xeon processors. Despite the rapid growth, Fouraker says the Intel Architecture enables the company to get value out of older machines.

"We're trying to bring screaming machines for the Web, so we bring the old ones back in and they make great internal servers. Very efficient use of hardware. I don't think we would have gotten that with RISC."

That capability has been crucial to Headhunter.net's processor-intensive service, says Fouraker. "We take more categorized information per resume or job than most people, so you can search and sort on more variables, can dig down deeper and hone itreally drive it down. With listings like a human resources director job in Omaha versus a C++ programmer in San Jose, there's a need to narrow it down."

Of course, cutting-edge performance doesn't matter for much if the site is down. And with millions of registered users browsing the site at all times of day and night, keeping the site available is a crucial concern. Of course, Headhunter.net's load-balancing and failover technologies are an important feature of the site. But Fouraker says that, ultimately, site availability boils down to the servers that drive it. "Our Pentium III Xeon processor-based servers are very stable, and they deliver screaming performance on the Web. We haven't lost a server yet."