Database Reference
In-Depth Information
the baseline successfully, as well as how to ensure you at least meet (if not exceed) your
system's required performance once it is virtualized. This applies even if the database
is being implemented first as a virtual machine—although in that case, you will design a
valid benchmark or load-test for that particular database to prove it meets your
requirements.
What Is a Performance Baseline?
A
performance baseline
is a measurement of a system with a known configuration
under known conditions that can be used as a reference point for further measurements
as configurations or conditions change. A baseline is often used to document “normal”
behavior under a known set of conditions. When you're developing a new system, the
performance baseline will normally include critical system metrics that give an
indication of good or bad performance as measured against a reference of the
nonfunctional requirements. An example of a nonfunctional requirement might be the
system achieves 450 transactions per second, with 95% of transactions serviced within
25ms latency.
When you're considering virtualizing an existing system, the process of recording the
baseline is more concerned with measuring what the current system performance is and
the critical metrics that make up that performance, rather than determining whether the
existing system's performance is good or bad.
Tip
The baseline is a measurement of what the current system performance is as well
as the critical metrics that make up that performance.
Before you begin to baseline your existing system, ask yourself this question: Are you
happy with how the system performs today? If the answer is “no,” then what makes you
think that moving it to a virtualized infrastructure alone will make it better?
Virtualization is not a silver bullet that solves all problems. When you virtualize a poor-
performing system, you should expect poor performance unless something changes. This
is one of the many reasons establishing a proper baseline is so important.
To better illustrate the value of a proper baseline, let's talk about a situation we had
happen earlier this year. We had as a client a very large engineering firm that went out
and purchased state-of-the-art hardware (both a new server and storage array) to run
their entire environment on. They moved just the database onto the new infrastructure.
They expected everything to get faster, yet the opposite happened. The new
infrastructure ran substantially slower than the older infrastructure that was running the
database and a number of other applications. After several failed attempts to correct the
problem with the new infrastructure, the firm called us in to determine why.
