Case study: Linux teaches QUT the easy way to scale
With tens of thousands of users who are often highly taxing on server infrastructure, managing IT in a university environment has always been a challenge. At Queensland University of Technology (QUT), however, this challenge has gotten easier in recent years thanks to a concerted shift away from proprietary Unix systems onto more-scalable clusters of standard Linux servers.
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QUT's more than 40,000 students and staff pursue research in a range of disciplines, many of them technical and therefore involving large volumes of data processed by purpose-built applications. Since each project has different requirements, the Information Technology Services (ITS) division found itself having to haphazardly add, and administer, all sorts of servers running different operating systems. Digital Tru64 UNIX, HP-UX, IBM AIX, Sun Microsystems Solaris, various flavours of Unix and several shades of Windows were amongst those dotting the university's datacentre.
Although they were effective computing platforms, these servers had intrinsic processing, memory and storage limits; when those limits were reached, the only solution was a very expensive one: "We were putting applications on midrange machines, but every time we got close to running out of server capacity, we had to buy another big box," says Joe Dascoli, associate director of ITS. "This wasn't an effective way to use the dollar of the university."
Strength in clusters
It didn't take long before the QUT team hit upon an approach that would provide a more cost-effective, flexible alternative to the university's proprietary Unix systems. That approach was based around Red Hat Enterprise Linux 4, which was loaded onto standard Intel processor-based servers co-ordinated by Oracle's RAC (real application clusters) technology.
RAC, an adjunct to Oracle's ubiquitous database, manages large numbers of standard servers as a single pool of computing and storage resources. As servers are added and removed, the system automatically redistributes the computing and data load across the remaining servers, providing a highly fault-tolerant and scalable computing environment.
For QUT, this approach was ideal from the start -- particularly given that the university was already using Oracle Financials and database in a limited sense. This meant the transition from its hodgepodge of technology standards to a fully Linux based environment could proceed relatively quickly and painlessly, without requiring the complex configuration and management issues inherent in the previous architecture.
"We've dabbled in the clustering technology well before this," says Dascoli. "What wasn't quite there for us was the way the application could quite legitimately sit over the multiple boxes in clustered form. Now that Oracle has invested a lot in that area, it's no longer a story; it's for real."
QUT introduced a policy favouring Linux as its preferred operating system, and over time the university has gradually reduced the presence of proprietary Unix servers within its datacentre. Just "two or three traditional IBM boxes" are still chugging away, with Linux-based clusters filling up the bulk of the datacentre's occupied real estate.
The new strategy has made it much easier to specify requirements for new projects -- and much easier to pay for them as well. In one current project -- development of a new student system -- the tender included a requirement for 30 to 40 Linux servers that would be used in an Oracle RAC cluster.
"It sounds like a big number, but the reality is that the cost of those 30 to 40 servers is a fraction of the cost of the old systems," Dascoli says. "In the old days you would have to pay AU$600,000 for a high-end server; now, the Linux servers are AU$3,000 each. This is the whole idea of being able to truly plug and play [new servers]."
The university's shift to Linux-based clusters has proven particularly useful in accommodating severe peaks in demand that are typical of university environments. With 40,000 students hammering the uni's servers for schedules in the weeks leading up to exams, and then again hitting the systems for results, those servers need to be able to quickly grow and shrink.
Because the cluster automatically integrates additional servers, ensuring performance during peaks only requires new systems to be installed -- and, because those systems run the free Linux operating system, doing so doesn't incur any additional cost apart from the hardware.
"If you notice that the peak has hit, you can add some more boxes to the cluster," says Dascoli. -It's not hard to pull boxes away from other services and redeploy them [in areas of need]; you don't have to physically relocate them, but can reallocate them virtually to some other app."
"It's like buying a tractor with 100hp but only ever using 2hp," he continues. "If you haven't got that 100hp once a year when you need it, your business goes broke. Being able to buy lots of little pieces, then bulk them together in whatever configuration we want, has been of strategic importance for this uni."
The Linux world
As at most universities, Linux was nothing new for QUT, having been used in scattered projects across the institution for some time. However, the shift from other operating systems onto a mission-critical Linux core still represented a major change, particularly given the traditional price and performance premium of high-end Unix servers.
"At the end of the day you're using a tool," Dascoli explains. "You do get that super-efficient functionality in some of those proprietary operating systems, but when it boils down to it you probably don't need those most of the time. The Linux platform is a very cost-effective option to any business that wants to go down that path; if it works 99 percent of the time and gives you bang for your buck, it has done the job."
Although Linux has become the standard for enterprise applications and services, the university still maintains some Windows servers for running .NET and other Windows-specific applications. However, in the main the uni's move to Linux has proved to be a valuable direction for the future by allowing it to leverage Oracle's RAC experience -- and not the hooks of complex high-end operating systems -- to provide the scalability, configurability and performance it requires.
"If you take an enterprise architecture view, and you have a look at the technology stack, we typically consume what's in our enterprise architecture on the basis of what's tried and proven," Dascoli explains. "Linux has certainly been that, and it is now embedded, explicitly and implicitly, in the enterprise architecture. We keep on using it because it works."
You said that .NET -based software will never be supported on Linux. That's not entirely true; Novell's Mono project enables a large number of .NET applications to run fine on Linux. We have a few such applications at our office that run on both platforms.