SAP is often considered the most mission-critical application in today's enterprises. Yet without a quality hardware infrastructure to run it, experts say that SAP application performance will be lacking. . .that is, if the applications don't go down completely.
The role that hardware has played in the overall SAP infrastructure has remained essentially unchanged for the past two decades, says Bruce Richardson, chief research officer of AMR Research.
"In the 20 years that I've been covering SAP, it went this way: You bought the software, then you met with the hardware team, then you bought your database, then made sure you had enough processing speed, storage and memory to run the software," Richardson said.
However, even though hardware plays a key role in SAP architectures, it's rarely described as "mission-critical." That term is usually reserved for software. In fact, some observers suggest that with hardware becoming more and more of a commodity in the enterprise computing landscape, being associated with it ranks lower on the IT status ladder than working with software.
"The increasingly popular view of IT hardware as a commodity is making hardware teams more like second-class citizens when compared with their software counterparts at some companies," said Michael Dortch, principal analyst and managing editor at DortchOnIT.com.
Although Dortch sees a renewed focus in companies today on the importance of hardware management,
Boring? Maybe. However, those servers and blades humming in the air-conditioned server rooms are the linchpins of the enterprise hardware infrastructure. When you're talking about a mission-critical SAP application in the enterprise, "every piece of high availability and redundancy is important," said Dan Wilhelms, president and founder of SymSoft Corp., a maker of GRC applications for SAP. Wilhelms was also one of the first Basis consultants hired by SAP America and he founded Symmetry Corp., a SAP Basis consulting organization.
"A day of downtime can cost an enterprise millions of dollars," Wilhelms said. "Well-managed, quality hardware is a component of a highly available and highly successful SAP environment."
Whether a company has the quality hardware for a successful SAP environment depends on how much it is willing to spend in order to meet performance targets. Risk-averse organizations are willing to spend more, since higher hardware budgets buy more redundant components, better service, more sophisticated virtualization techniques and more reliable storage systems.
But what constitutes a quality server? The various hardware components in an SAP infrastructure are so interdependent that it's hard to make this determination in today's enterprise IT environments.
"You can have the fastest server in world," said Frank J. Ohlhorst, an independent hardware consultant and former IT administrator. "But if the network backbone is congested, you're not going to have peak performance."
Setting up the SAP hardware infrastructure
The first step in setting up the hardware configuration in an SAP environment is determining your hardware vendor. Prospective hardware vendors will meet an SAP customer to calculate its SAP Application Performance Standard (SAPS) – a unit of measurement that SAP uses to estimate workload. This helps determine whether a company will use a very small, small, medium, large or very large SAP landscape template.
SAP offers hardware sizing software online. The company's Quick Sizer tool translates the business requirements of an SAP system into hardware-independent technical requirements that help a company select the proper hardware system for its business goals. SAP's hardware partners then size the infrastructure by translating SAP's benchmarks into their own, such as IBM's rPerfs. Some hardware partners have their own sizing algorithms to supplement the SAP numbers.
According to SAP DB, The Unofficial SAP Knowledge Base, a typical SAP hardware landscape consists of a Development (DEV) instance), a Quality Assurance (QAS) or Test instance, and Production (PRD) instance. However, PRD should not share a server with any other SAP instance.
Furthermore, depending on the complexity of the SAP implementation, other servers might be required. For example, a separate server is usually required for a Solution Manager instance.
Factors in configuring an SAP hardware environment
Many factors determine how an SAP customer configures a hardware environment. "IT developments, enhancements, unique business processes, usage patterns and batch window SLAs may affect the hardware appetite significantly," said Justin Burmeister, an independent Basis and NetWeaver consultant.
"Quick Sizer numbers are often supplemented by real-world performance and stress testing cycles in a representative test system that has production-like data volumes and hardware. This is usually the best test, quantifying CPU, RAM and I/O high water marks in a real-world scenario. Sometimes SAPS benchmarks can be reverse-engineered and extrapolated from these tests.
Once the hardware vendor is chosen, SAP Basis administrators will determine how much of a role hardware will play in their mission to attain the best performance from their SAP applications.
Determining SAP software performance targets depends on many factors – whether users are accessing the application through a traditional TCP/IP environment, a virtualized environment or a hosting service; and whether the application is disk-intensive or memory-intensive.
When application response time is slow, Burmeister said that an application manager can tune the code, revisit business processes or "throw hardware" at the issue.
"Assuming the [SAP] environment is sufficiently sized with enough capacity at the application and database tiers," he said, "faster CPUs can certainly make lousy code run faster."
And when an application is well-designed, "the more RAM you throw at it, the better its performance," said Ohlhorst. If the application is able to load the majority of itself into RAM and use disk caching, then disk I/O is not that important. If not, disk subsystems make a big difference.
Other factors that should be considered include network latency, WAN bandwidth requirements and PC requirements for the SAPGUI/BEx front-end, or any high availability requirements.
"Most major hardware partners have an SAP Competency Center that can help support these issues," Burmeister says. Another factor is how many threads are in the application. "Putting a single-threaded application on a multi-threaded server doesn't give you any advantage," Ohlhorst said. "If you go with multi-threaded applications, you'll want a quad-core CPU and server."
Hardware purchasing patterns changing with the times
There's a growing feeling among many observers that as servers get more powerful, they will change the way that enterprise software runs and may even change the way it's developed. That's why Wilhelms recommends that his customers refresh the hardware in their SAP environments every three years.
"Older hardware tends to fail," he said. "And the new hardware is so much faster, that you can save 1/10 of a second on every transaction you hit. If you're doing thousands of transactions per month, that can be a huge source of productivity for companies."
But Ohlhorst said that a three-year refresh may be a luxury that not every company can afford in today's economy. "We've gotten off the hamster wheel of upgrading hardware every three to five years," he said. "Now there has to be a business need behind a hardware upgrade."
According to Ohlhorst, more and more it's the CFO who decides on a hardware refresh. "CFOs these days are focusing on the ROI of hardware and software upgrades. The argument that the hardware is old doesn't cut it anymore. These days, hardware is a bottom-line decision."
So bottom-line that AMR's Richardson envisions hardware moving to the cloud. At the outset of this article, he said that the hardware procurement process has remained the same for 20 years. But now it's changing radically.
According to Richardson, "Companies are starting to ask themselves, why even bother owning the hardware?"