Introduction to Performance Testing – LoadRunner Training Tutorial Part 1

Today, we are starting ‘Performance testing with LoadRunner’ tutorial series. This is the first tutorial in three-part HP LoadRunner training series.

In first two tutorials we will introduce you to performance testing and in last tutorial we will share ‘Load Testing with LoadRunner video tutorials‘.

See Also => List of all LoadRunner Video Tutorials.

Why Performance testing?

Performance testing has proved itself to be crucial for the success of a business. Not only does a poor performing site face financial losses, it also could lead to legal repercussions at times.

Performance testing intro

No one wants to put up with a slow performing, unreliable site in cases of purchasing, online test taking, bill payment, etc. With the internet being so widely available, the alternates are immense. It is easier to lose clientele than gain them and performance is a key game changer.

Therefore, performance testing is no longer a name sake checkpoint before going live. It is indeed a comprehensive and detailed stage that would determine whether the performance of a site or an application meets the needs.

Introduction

The purpose of this test is to understand the performance of application under load, particularly users.

Types of Performance Testing

Performance testing types

Load Testing

Load testing is a type of performance test where the application is tested for its performance on normal and peak usage. Performance of an application is checked with respect to its response to the user request, its ability to respond consistently within accepted tolerance on different user loads.

The key considerations are:

  1. What is the max load the application is able to hold before the application starts behaving unexpectedly?
  2. How much data the Database is able to handle before system slowness or the crash is observed?
  3. Are there any network related issues to be addressed?

Stress Testing

Stress testing is the test to find the ways to break the system. The test also gives the idea for the maximum load the system can hold.

Generally Stress testing has incremental approach where the load is increased gradually. The test is started with good load for which application has been already tested. Then slowly more load is added to stress the system and the point when we start seeing servers not responding to the requests is considered as a break point.

During this test all the functionality of the application are tested under heavy load and on back-end these functionality might be running complex queries, handling data, etc.

The following questions are to be addressed:

  • What is the max load a system can sustain before it breaks down?
  • How is the system break down?
  • Is the system able to recover once it’s crashed?
  • In how many ways system can break and which are the weak node while handling the unexpected load?

Volume Testing

Volume test is to verify the performance of the application is not affected by volume of data that is being handled by the application. Hence to execute Volume Test generally huge volume of data is entered into the database. This test can be incremental or steady test. In the incremental test volume of data is increased gradually.

Generally with the application usage, the database size grows and it is necessary to test the application against heavy Database.  A good example of this could be a website of a new school or college having small data to store initially but after 5-10 years the data stores in database of website is much more.

The most common recommendation of this test is tuning of DB queries which access the Database for data. In some cases the response of DB queries is high for big database, so it needs to be rewritten in a different way or index, joints etc need to be included.

Capacity Testing

=> Is the application capable of meeting business volume under both normal and peak load conditions?

Capacity testing is generally done for future prospects.  Capacity testing addresses the following:

  1. Will the application able to support the future load?
  2. Is the environment capable to stand for upcoming increased load?
  3. What are the additional resources required to make environment capable enough?

Capacity testing is used to determine how many users and/or transactions a given web application will support and still meet performance. During this testing resources such as processor capacity, network bandwidth, memory usage, disk capacity, etc. are considered and altered to meet the goal.

Online Banking is a perfect example of where capacity testing could play a major part.

Reliability/Recovery Testing

Reliability Testing or Recovery Testing – is to verify as to whether the application is able to return back to its normal state or not after a failure or abnormal behavior- and also how long does it take for it to do so(in other words, time estimation).

An online trading site if experience a failure where the users are not able to buy/sell shares at a certain point of the day (peak hours) but are able to do so after an hour or two. In this case, we can say the application is reliable or recovered from the abnormal behavior.

In addition to the above sub-forms of performance testing, there are some more fundamental ones that are prominent:

Smoke Test:

  • How is the new version of the application performing when compared to previous ones?
  • Is any performance degradation observed in any area in the new version?
  • What should be the next area where developers should focus to address performance issues in the new version of application?

See also => Smoke Testing in functional testing.

Component Test:

  • Whether the component is responsible for the performance issue?
  • Whether the component is doing what is expected and component optimization has been done?

Endurance Test:

  • Whether the application will able to perform well enough over the period of time.
  • Any potential reasons that could slow the system down?
  • Third party tool and/or vendor integration and any possibility that the interaction makes the application slower.

How does Functional Testing differ from Performance Testing?

Functional vs Performance Testing

Identification of components for testing

In an ideal scenario, all components should be performance tested. However, due to time & other business constraints that may not be possible. Hence, the identification of components for testing happens to be one of the most important tasks in load testing.

The following components must be included in performance testing:

------------

#1. Functional, business critical features

Components that have a Customer Service Level Agreement or those having complex business logic (and are critical for the business’s success) should be included.
Example:  Checkout and Payment for an E-commerce site like eBay.

#2. Components that process high volumes of data

Components, especially background jobs are to be included for sure. Example: Upload and download feature on a file sharing website.

#3. Components which are commonly used

A component that is frequently used by end-users, jobs scheduled multiple times in a day, etc.
Example: Login and Logout.

#4. Components interfacing with one or more application systems

In a system involving multiple applications that interact with one another, all the interface components must be deemed as critical for performance test.
Example: E-commerce sites interface with online banking sites for payments, which is an external third party application. This should be definitely the part of Perf testing.

Tools for performance testing

Sure, you could have a million computers set up with a million different credentials and all of them could login at once and monitor the performance. Apparently it’s not practical and even if we do, do that, we still need some sort of monitoring infrastructure.

The best way this situation is handled is through – virtual user (VU). For all our tests the VU behave just the way a real user would.

For the creation of as many VUs as you would require and to simulate real time conditions, performance testing tools are employed. Not only that, Perf testing also tests for the peak load usage, breakdown point, long term usage, etc

To enable all with limited resources, fast and to obtain reliable results tools are often used for this process. There are a variety of tools available in the market- licensed, free wares and open sourced.

Few of the such tools are:

  • HP LoadRunner,
  • Jmeter,
  • Silk Performer,
  • NeoLoad,
  • Web Load,
  • Rational Performance Tester (RTP),
  • VSTS,
  • Loadstorm,
  • Web Performance,
  • LoadUI,
  • Loadster,
  • Load Impact,
  • OpenSTA,
  • QEngine,
  • Cloud Test,
  • Httperf,
  • App Loader,
  • Qtest,
  • RTI,
  • Apica LoadTest,
  • Forecast,
  • WAPT,
  • Monitis,
  • Keynote Test Perspective,
  • Agile Load, etc.

See Also => List of top 15 Performance Testing tools

The tool selection depends on budget, technology used, purpose of testing, nature of the applications, performance goals being validated, infrastructure, etc.

HP Load Runner captures majority of market due to:

  1. Versatility – can be used on windows as well as web based applications. It also works for many kinds of technologies.
  2. Test Results – It provides in-depth insights that can be used for tuning the application.
  3. Easy Integrations – works with diagnostics tool like HP Sitescope and HP Diagnostic.
  4. Analysis utility provides a variety of features which help in deep analysis.
  5. Robust Reports – LoadRunner has a good reporting engine and provides a variety of reporting formats.
  6. Comes with an Enterprise package too.

The only flip side is its license cost. It is a little bit on the expensive side – which is why other open source or affordably licensed tools that are specific to a technology, protocol and with limited analysis & reporting capabilities have emerged in the market.

Still, the HP LoadRunner is a clear winner.

Future in Performance Testing Career

Performance testing is easy to learn but need lots of dedication to master it. It’s like a mathematics subject where you have to build your concept. Once the concept is through, it can be applied to most of the tools irrespective of the scripting language being different, straight forward logic not being applicable, look and feel of the tool being different, etc. – the approach to Perf testing is almost always the same.

I would highly recommend this hot and booming technology and to enhance your skill by learning this. Mastering PT could be just what you are looking for to move ahead in your software testing career.

Conclusion

In this article we have covered most of the information required to build a base to move ahead and understand the Performance testing.  In the next article we will apply these concepts and understand the key activities of Performance testing.

Next Tutorial => How to Performance Test an Application

Load Runner is going to be our vehicle in the journey, but the destination we want to reach is to understand everything about performance testing.

Stay tuned!

About the Author: Chetan Kaushal is helping us for this ‘Performance testing with LoadRunner’ tutorial series. He is having over 6 years of experience working on performance testing projects using HP LoadRunner and Performance Center tools.

In the meantime if you have any questions related to performance testing, load testing or LoadRunner please ask them in the comments below.



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37 comments ↓

#1 Topher on 01.07.14 at 2:39 am

Thank you so much for this great article. It really informative. Keep up the good work :)

#2 Kiran on 01.07.14 at 3:06 am

Can you please add tutorial of Jmeter.

#3 Rakesh on 01.07.14 at 3:40 am

Nice article to know the funda of performance testing

#4 Pravin on 01.07.14 at 4:33 am

Many Thanks for sharing this articles.

#5 Udara on 01.07.14 at 5:02 am

Can you please add tutorial for selenium & Jmeter.

#6 Udara on 01.07.14 at 5:06 am

can u pls add tutorials for selemium & jmeter.

#7 Pallavi on 01.07.14 at 5:12 am

Thanks for this article. Good information shred for performance testing basics.

Along with Load runner can you please share tutorial for performance testing tool – Cloud test.

#8 Ankit on 01.07.14 at 5:21 am

when we will grt its second tutorial ? After 2 3 days ihave to work on load runner.so pls post it soon :(

#9 Sachin on 01.07.14 at 5:33 am

Great Documentation on the Performance testing terms (statements) .. :)

Now, the question which always arrives in my mind about performance testing is -

What is the actually time to do (start) performance testing ?

As we know the performance testing deals with load, stress, Volume testing…., so is that mean we should do performance testing at the end of development process, or if not……. then what is the relevant way to begin with performance testing in Software Project ?

Kindly elaborate your points on above issue.

#10 Bhavesh on 01.07.14 at 5:36 am

Thanks for such a informative articles on performance testing.

#11 sathish on 01.07.14 at 6:03 am

Good Article

#12 Yogesh on 01.07.14 at 6:06 am

How to decide the application performance is good or poor?
Suppose there is application take 1 hr to send the 1GB file to database,So how to decide its performance?

#13 Ashu on 01.07.14 at 6:18 am

I would like to pursue my software testing career ahead into performance testing. what are the job opportunities available in this respect to performance testing.

Please suggest

#14 sarvesh on 01.07.14 at 7:15 am

Thanx Vijay for this greate intresting article……..thanx again…

#15 Chetan on 01.07.14 at 9:59 am

Thanks everybody for appreciating the article and work.

#16 Chetan on 01.07.14 at 10:02 am

@Kiran, @Udara- We will definitely consider your request. Thanks

#17 Chetan on 01.07.14 at 10:20 am

@Sachin-Previously when Performance testing was not given so much importance so it was done at the end and whatever were the minimum changes required to tune the application after the performance testing were considered . But now industry is very much aware of need of Performance testing. So the culture is now to have “Built to Performance” application where performance of application is checked from time to time.

Developers check the performance of their code in unit testing through profilers. And when a functionality is ready to test, Performance team starts their performance testing and give feedback to Dev team so that they can fix the performance issues along with the release of next functionality. So with each release Dev team keep adding functionality and tuning the application in their integration phase.

#18 Bamidele on 01.07.14 at 10:46 am

You have tremendously educate me about performance testing. Thanks.

#19 Vijay on 01.07.14 at 3:29 pm

@ Ankit – Video tutorials will be on Monday.

#20 Anusha on 01.07.14 at 5:29 pm

when can we get the next part of tutorial and practical session?

#21 Kedara on 01.07.14 at 9:29 pm

Thank you and please also help us on Selenium…:)

Thanks In Advance

#22 Sumit Jaiswal on 01.08.14 at 5:33 am

It’s great article for the Beginner’s.
I would be expecting more practical example’s, apporach , and solution to the error’s which we encountered while creating Load Script’s and Performance Test.

Hope you full fill my expectation.

All the Best.

#23 priyanka on 01.08.14 at 6:20 am

Great article!! Can u please provide tutorials for JMeter…
:)

#24 Sachin on 01.08.14 at 7:56 am

@ Chetan.

Thanks a lot Sir !

Firstly you understan dmy Question very much exact.
and the answer is great along with the Software Development Track.

Really Nice :)

Thanks,
Sachin

#25 Sachin on 01.08.14 at 8:06 am

@ Yogesh.

Below are two bullet points i would like to mention (for answering you) -

1. PM (Product Manger) should decide the Performance limits. and if your Application (software) full fill the limits than the Performance is as Expected.

In your example first you should know what is the expected behaviour (expected speed) and then you can say it is Good or Poor.

2. Performance Testing has Load testing, Stress Testing, Volume Testing… (you can see in tutorial above).
So if all this Testing Results are Good (Actual Result = Expected Result) then the performance is Good and if not you can guess it.

Your nots are Welcome !

#26 Anthony on 01.08.14 at 10:18 am

Excellent article to understand the need of Performance Testing.

#27 Merlyn on 01.08.14 at 6:09 pm

Thanks. Excellent material.
Looking forward to the tutorials which I expect to cover not merely basics.

#28 Pravin on 01.08.14 at 6:43 pm

Hello Chetan,
Thanks,Really helpful material.
Please tell me how to write performance testing test cases manually.
pravinyeole04@gmail.com

#29 Ritu on 01.09.14 at 12:19 am

Thanks for article

#30 chetan J on 01.09.14 at 12:03 pm

Thanks for your efforts Chetan Kaushal. i am the old reader of this blog can we start same tutorial for Jmeter I am interested in Jmeter because of open source, any help from your side will be helpful.

#31 Gourav Soni on 01.10.14 at 10:33 am

Hello Sir,

I am very thank full to you that u understand me, what is performance testing exactly…thanks alot my blassings are with you….

Keep it up sir……

#32 Sudhakar on 01.13.14 at 9:55 pm

Thankq so much for providing very useful information :-)

#33 Sangram Kumar Das on 01.15.14 at 5:06 pm

Thanks for this Article. This is a nice Documentation on the Performance testing terms and statements.

Looking forward to your next article.

#34 Girish on 02.11.14 at 9:35 am

Thanks! Amazing artical on Performance Testing.
Good Work Thank you so much.

#35 Dipesh on 02.24.14 at 7:54 am

I just want to know that theoritically the article was best and can we have practise of this at home…I mean to say is it essential that we should work in a corporate for getting full hands on experience of load runner.

We can learn it from here but where can we practise these steps any link from where we can download.

#36 ade on 04.14.14 at 10:07 pm

Can some please tell me what problems they have faced doing perf testing and how it was resolved..?

#37 prakash on 04.16.14 at 9:03 am

hello sir,actually i am a begginer for load runner and i know all the basics.but i want to learn loadrunner scripting using c.and i search everywhere.so can anyone please help me to how to start the scripting part.

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