Evaluating Performacne the Customer Way!

We currently ran the performance testing for one of our prestigious customer.The tool we used for the test was load Runner . The test was supposed to be by two team one our team and another Customer team. We started the test on Customer database with 2500 CC and it got failed. The same test when run on our
internal Performance database and we have found that the test was scaling easily to 2500 CC and there comes out first learning

1. Evaluate the Volume of Database against when test is been done.
2. Evaluate the scenario against which UAT sign off is required.

Initial test runs failed and after multiple fixes we were able to successfully achieve 2500 CC. By the time we finished this test customer came up with his script and think time and we modified the script according to their think time and test again failed.Here comes my second learning

1. Never assume the think time even you are SME.
2. Hits/sec under certain concurrency is what Customer looks for.

Apart from the think time the customer did the URL mode scripting while we were doing the HTML based , currently we are running the test with context sensitive while out
Customer is running with Context Insensitive mode.

One can read moe about the Context Insensitive vs Context Sensitive on the blogs

Basic Web Performance Part 5

As we progress on our journey to performance test our web application. I think it would be appropriate to introduce few key terminology we use in our performance testing.It is important to know what are expectations from our performance testing and certain do and don't . so let me get started as i am not going to explain those terms here you might have to figure out yourself :)
Key Terminology

•  Ramp Up/Ramp down
•  Users/Threads
• Iterations
• Through put
• WorkLoad/Business Flow
• Request/Response
• Load/Stress

Why Do Performance testing

1. Assessing release readiness
2. Assessing infrastructure adequacy
3. Assessing software performacne adequacy
4. Collecting metrics for Performance Tuning

Do and Don't

There are certain do and donts before you perform the performance test.These are again the guideline and all of them might not be applicable.

Do

• Suitable time to Load test when all the parameters like network , user access, application access are under control.
• Define the performance metrics , accepted level or SLA and goals.
• Know the objective of test.
• Know the Application Under Test architecture and details like protocol supported , cookies manages etc.
• Know the Workload Scenarios and peak and normal usage time before the test.
• Use the meaningful test scenario to construct Test Plan which is real life .
• Run the tool on machine other than that running the Application.
• Machine running the tool should have sufficient network bandwidth and resources(memory,CPU).
• Run the test for long duration to have minimum deviations.
• Ensure the application is stable and with no errors logged on log files by manually browsing the application.
• Incorporate the think time to emulate real life scenario.
• Keep Close watch on following (processor, memory,disk and network)

Don't

• Never run the test against servers which are not assigned to test, else you may be accused of DoS attack.

You can see more on performance testing on the blog http://prashantbansode.blogspot.in/

In the next article we will see how we can follow these guidelines and start on performance testing with JMETER!!

Basic Web performance Part 4

While previous articles we have loooked upon the website request response in more single user scenario. This may not be the case as most of company website / web product would be used by thousands/ millions of user. Some transaction might be used by few thousands users while some might be used by millions.It is advisable to properly test your website with more real life user distribution and this  cannot happen by manually and we need to automate the process.We need tools support and we have broadly categorize the tool into two classes
1. Open Source
2. Commercial
There might be more subtle difference before you choose a tool like protocol support, vusers support , learning curve  etc. Since our discussion is limited to web application we will focus on HTTP protocol here. The tools in open source category are OpenSTA, Jmeter while on another side commercial tools like LoadRunner , WebLoad, Rational tools. We choose Jmeter for our testingfor below reasons

1. Jmeter can be used for testing static and dynamic resource
2. Can support heavy load i.e. users
3. Great analysis for the performacne results/metrics
4. High extensible with support on javascript/groovy etc to enhance the script.
5. And Lastly No License Cost!!   

How to Install
Since it is open source you can do a quick googling , binging and get the executable download. More precisely you can go to
http://jmeter.apache.org/index.html and under download on left pane there is Download Releases latest is 2.9 version with prerequisites for java 6  . Under the binaries you can get the .zip or .tgz based on the operating system you are planning to install.For some reason you want to install older version you can go to Archives and download the version interested in.

Jmeter Launch
Once you have extracted the files , you will see bin,docs,extras,lib,printabledocs and few auxiliary files. You need to got to the bin folder and launch the jmeter.bat file this will launch the Jmeter and you will see something as below. The left pane on below screen contains the Elements of Jmeter and right pane is for configuration the settings for these elements.

We will talk more about the elements in jmeter in our next session and also touch base on some key terminologies in performance testing.