Stress Testing
Stress Testing is
a type of software testing that verifies stability & reliability of
software application. The goal of Stress testing is measuring software on its
robustness and error handling capabilities under extremely heavy load
conditions and ensuring that software doesn't crash under crunch situations. It
even tests beyond normal operating points and evaluates how software works
under extreme conditions.
In
Software Engineering, Stress Testing is also known as Endurance Testing. Under
Stress Testing, AUT(Application under test) is be stressed for a short period of time to
know its withstanding capacity. A most prominent use of stress testing
is to determine the limit, at which the system or software or hardware breaks.
It also checks whether the system demonstrates effective error management under
extreme conditions.
The
application under testing will be stressed when 5GB data is copied from the
website and pasted in notepad. Notepad is under stress and gives 'Not
Responded' error message.
Importance of Stress Testing
Consider the following scenarios -
- During
festival time, an online shopping site may witness a spike in traffic, or
when it announces a sale.
- When
a blog is mentioned in a leading newspaper, it experiences a sudden surge
in traffic.
It is imperative to perform Stress Testing to accommodate such
abnormal traffic spikes. Failure to accommodate this sudden traffic may result
in loss of revenue and repute.
Stress testing is also extremely valuable for the following
reasons:
- To
check whether the system works under abnormal conditions.
- Displaying
appropriate error message when the system is under stress.
- System
failure under extreme conditions could result in enormous revenue loss
- It
is better to be prepared for extreme conditions by executing Stress
Testing.
|
Load
Testing |
Stress
Testing |
Load Testing is to test the system behavior under normal workload
conditions, and it is just testing or simulating with the actual workload |
Stress
testing is to test the system behavior under extreme conditions and is
carried out till the system failure. |
|
Load
testing does not break the system |
stress
testing tries to break the system by testing with overwhelming data or
resources. |
Types of Stress Testing:
Distributed
Stress Testing:
Application
Stress Testing:
This testing concentrate on finding defects related to data
locking and blocking, network issues and performance bottlenecks in an
application.
Transactional
Stress Testing:
It does stress testing on one or more transactions between two
or more applications. It is used for fine-tuning & optimizing the system.
Systemic
Stress Testing:
This is integrated stress testing which can be tested across
multiple systems running on the same server. It is used to find defects where
one application data blocks another application.
Exploratory
Stress Testing:
This is one of the types of stress testing which is used to test
the system with unusual parameters or conditions that are unlikely to occur in
a real scenario. It is used to find defects in unexpected scenarios like
1.
A large number of users logged at the same time
2.
If a virus scanner started in all machines simultaneously
3.
If Database has gone offline when it is accessed from a website,
4.
When a large volume of data is inserted to the database
simultaneously
How to do Stress
Testing?
Stress Testing process can be done in 5 major steps:
1.
Planning the Stress Test. Here you gather the system data,
analyze the system, define the stress test goals
2.
Create Automation Scripts: In this phase, you create the Stress
testing automation scripts, generate the test data for the stress scenarios.
3.
Script Execution: In this stage, you run the Stress testing
automation scripts and store the stress results.
4.
Results Analysis: In this stage, you analyze the Stress Test
results and identify bottlenecks.
5.
Tweaking and Optimization: In this stage, you fine-tune the
system, change configurations, optimize the code with goal meet the desired
benchmark.
Lastly, you again run the entire cycle to determine that the
tweaks have produced the desired results. For example, it's not unusual to have
to 3 to 4 cycles of the Stress Testing process to achieve the performance goals.
Tools recommended for Stress Testing:
LoadRunner
LoadRunner from HP is a widely-used Load Testing tool. Load Test
Results shaped by LoadRunner are considered as a benchmark.
Jmeter
Jmeter is an Open Source testing tool. It is a pure java application
for stress and Performance testing. Jmeter is intended to cover types of tests like load, functional, stress, etc.
It needs JDK 5 or higher to function.
Stress
Tester
This tool provides extensive analysis of the web application
performance, provides results in graphical format, and it is extremely easy to
use. No high-level scripting is required and gives a good return on investment.
Neo
load
This is a popular tool available in the market to test the web
and Mobile applications.
This tool can simulate thousands of users in order to evaluate the application
performance under load and analyze the response times. It also supports
Cloud-integrated - performance, load and stress testing. It is easy to use,
cost-effective and provides good scalability.