All the theory, calculations, and estimations in the world aren’t going to tell
you how your website will truly perform under a load. If you’re deploying a new
server or doing any kind of performance enhancements, you don’t want to test
your results in production. It’s always a good idea to see how your system
behaves before your visitors do. To do that, you can use a load testing tool,
and here are a few I use quite frequently.
Update: I’ve featured these tools in my latest
IIS course on Pluralsight, IIS Administration in Depth,
check it out!
Netling
Download
Netling Here
One of the
“quick and dirty” applications I use is Netling. This is a super simple tester
written in C#. You will need to compile this with Visual Studio, but you don’t necessarily
have to be a developer to do it. I’ve been able to load it up and select build
to create it with no modifications with many versions of Visual Studio.
Netling is
super simple to operate and about as easy as it gets.
You select how
many threads you want to run. This is entirely up to you, more threads will put
more load on your machine, and depending on how many cores your CPU has, more
may not necessarily be better. Experiment with it and see what works best for
you.
It has a
feature for “Pipelining”. This is when multiple requests go through a single
socket without waiting for a response. Setting this higher will generate a
higher load but again this something to adjust for best results. There will be
a physical limit to pipelining depending on your hardware and connection speed.
This is a handy
tool and is extremely simple to use. One issue I’ve had with netling is it
sends raw requests that aren’t much like a real browser. To emulate real
traffic more accurately I have another tool I like to use.
Netling Pros
- Free
- Open Source,
can be easily modified
- Extremely
Simple
Netling Cons
- Doesn’t
simulate real transactions well
- Can’t do
authentication or other simulations
- Only tests one
URL at a time
Web Surge
Download Web
Surge Here
Web surge is by
far one of my favorites. It’s a great application that simulates a load on your
server in a very realistic fashion.
With this
program you create sessions, which means you can use more than one URL for the
test. Each of the URLs will be run in the session, which can make it more
random and realistic. It has a ton of great options as well:
It gives you
quick results, and you can “drill down” to get more detailed data.
You can also
export these results in several formats. There’s the websurge proprietary
format, as well as XML or JSON. You could parse these results for future
analysis work.
Overall
Websurge is among my favorites for load testing because it’s closer to real
world traffic. If you put in a list of all your pages and randomize the test,
it can provide some solid information.
Web Surge Pros
- Free (for
personal use)
- Professional
Version reasonably priced
- Fast and
generates a large load
- Simple to use,
yet powerful
- Simulates “real
world” traffic very well
- Extremely
configurable
Web Surge Cons
Apache JMeter
Download JMeter
Here
The Next
application we’ll look at is JMeter. This is an extremely powerful program and
can do very thorough testing in addition to generating a load. In fact, load
testing with JMeter is just a very small part of its overall functionality.
With JMeter you
have scenarios to run out, because it’s more of a testing-oriented application
you can run through a longer set of steps and processes as a part of your test.
I would
encourage you to really dig into this application and learn as much as you can
about it to get the full benefits of it.
Apache JMeter Pros
- Free
- Very Powerful
- Detailed tests
can be set up
- Minimal setup
Apache JMeter Cons
- Steeper
learning curve
- Can be fairly
complicated
- May be overkill
for what you need
Conclusion
There are many
tools out there for load generation, but these are the ones I use the most. I
like to set up various different tests to accurately gauge performance of your
website and it’s reaction to a load.
In fact, the
reaction to a heavy load is the most important thing I’m looking for. When
doing performance measurements, it’s difficult to really nail down all the
variables and prove a change has increased performance. But sending a heavy
load to your server and seeing how it reacts is conclusive.
I cover some
performance and stability enhancements in my Pluralsight Course - IIS Administration Fundamentals.
I cover load
testing in detail in my new course IIS Administration In Depth.
Check it out if
you want to learn more about administering IIS Servers.
About the Author
Jeremy Morgan is a software engineer with over a decade of experience as a polyglot coder, dabbling in both LAMP and .Net worlds equally. He enjoys creating tutorials for new programmers in the hopes it will encourage more people to join this exciting hobby. Check out his programming blog here or say hi on Google+ sometime.