What is 'Load Testing' exactly?
The answer to that question might seem easy!
Well, sort off. (I should say I'm going to write this site like a blog, as things come to mind, so please bear with me if it's a bit convoluted in places...)
I'll define 'load testing' as:
'Simulating real application load, in actual user scenarios, checking response times and long term stability.'
And the main aims in a commercial environment are:
Confirm that the latest application release will work in PRODUCTION, before sending it live.
Confirm that the latest release can service the full user load required
Confirm that it is stable, long term, avoiding support team input being required for things like restarts etc.
There are of course a lot more details and there are questions such as the benefits and
the value of even trying to do this. I'll try to cover as much of this as I can in these pages,
along with how to get started commercially, from a QA or Developer role.
Getting started on this as a full time job can be difficult, mainly because computer system
are necessarily complex and to do the job in a commercial environment, you do really need
experience in these environments and to know how things fit together. And that includes teams
of people, not just the machines. You need to be able to communicate with all the different teams
and know who to talk to about all sorts of different technical issues.
I will try to cover as much ground as I can within these pages. It is a bit trial and error, depending on what's on my
plate currently and how much free time I have to write it all up. Hopefully, this page will
become more useful over time.
Areas I want to cover
I want to build a tutorial here, not for absolute beginners, but for developers or technical QAs
who want to move into Performance Testing.
3. Test data in theory and practice
4. What you need to know about websites (this tutorial concentrates on HTTP applications in the main)
5. Test passes and fails, SLAs and other requirements
7. Graphs, analysis sessions and management reports
8. More on Caches, data, Databases and test data selection etc.
Something to watch out for
It is easy in this field to get over-enthusiastic - to start ramping up the load, to see how far
we can go... And this does have some benefits SOMETIMES. But you also need to be aware that
computer systems are complex and clever. So as you change the load, they start to behave
differently. They are designed to do this. And that means that it is easy to veer off from the
required application behaviour. So it is important to make sure you are testing at realistic
loads. Sometimes that will be very high peak loads that last a short time and sometimes it
could be low level sustained loads, that carry on for hours, maybe days. And each of these
scenarios need testing individually AND realistically - that means matching real log file activity...