Logic Controllers Jmeter

Logic Controllers

Logic Controllers determine the order in which Samplers are processed.

1)Loop Controller

If you add a Loop Controller, JMeter will loop through them a certain number of times, in addition to the loop value you specified for the Thread Group.

For example, if you add one HTTP Request to a Loop Controller with a loop count of two, and configure the Thread Group loop count to three, JMeter will send a total of 2 * 3 = 6 HTTP Requests.

2)Once Only Controller
The Once Only Logic Controller tells JMeter to process the controller(s) inside it only once per Thread, and pass over any requests under it during further iterations through the test plan.

The Once Only Controller will now execute always during the first iteration of any looping parent controller. Thus, if the Once Only Controller is placed under a Loop Controller specified to loop 5 times, then the Once Only Controller will execute only on the first iteration through the Loop Controller (ie, every 5 times).

More to come..

Risks Addressed Through Performance Testing

Speed related risks

Ensure that your performance requirements and goals represent the needs and desires of your users,

Compare your speed measurements against previous versions and competing applications.

Design load tests that replicate actual workload at both normal and anticipated peak times.

Conduct performance testing with data types, distributions, and volumes similar to those used in business 

operations during actual production

Include time-critical transactions in your performance tests.

Validate that all of the correct data was displayed and saved during your performance test.

Scalibility Related Risks

Compare measured speeds under various loads.

When you find a scalability limit, incrementally reduce the load and retest to help you identify a metric that can serve as a reliable indicator that the application is approaching that limit in enough time for you to apply countermeasures

Conduct performance tests beyond expected peak loads and observe behavior by having representative users and stakeholders access the application manually during and after the performance test.

Validate the functional accuracy of the application under various loads by checking database entries created or validating content returned in response to particular user requests.

Stability Related Risks

Take a server offline during a test and observe functional, performance, and data-integrity behaviors of the remaining systems.

Include error or exception cases in your performance test scenarios (for example, users trying to log on with improper credentials

Apply a patch to the system during a performance test

Force a backup and/or virus definition update during a performance test.

Make time for realistic endurance tests 

Source : Various websites

Baseline and BenchMarking

Baseline : Creating a baseline against which to evaluate the effectiveness of subsequent performance-improving changes to the system or application will generally increase project efficiency.

Benchmarking : is the process of comparing your system’s performance against a baseline that you have created internally or against an industry standard endorsed by some other organization.

Source : Various websites

Categories of performance testing

Performance testing : Performance is concerned with achieving response times, throughput, and resource-utilization levels that meet the performance objectives for the project or product

Load testing : Validating performance characteristics of the system or application under test when subjected to workloads and load volumes anticipated during production operations

Stress testing : Validating performance characteristics of the system or application under test when subjected to conditions beyond those anticipated during production operations. Stress tests may also include tests focused on determining or validating performance characteristics of the system or application under test when subjected to other stressful conditions, such as limited memory, insufficient disk space, or server failure. 

Source : Various websites

What is Performamce tuning??

When end-to-end performance testing reveals system or application characteristics that are deemed unacceptable, many teams shift their focus from performance testing to performance tuning,

When the tests reveal performance characteristics deemed to be unacceptable, the performance testing and tuning team enters a diagnosis and remediation stage (tuning) that will require changes to be applied to the test environment and/or the application. 

Source : Various websites

Why we do performance testing??

Why we do performance testing??

1)For Assessing release readiness

Helps sstakeholders who make decisions about whether an application is ready for release for handling future growth, or whether it requires a performance improvement/hardware upgrade prior to release

2)For Assessing infrastructure adequacy

Determining the capacity of the application’s infrastructure, as well as determining the future resources required to deliver acceptable application performance

Verifying that the application exhibits the desired performance characteristics, within budgeted resource utilization constraints.

3)For Assessing adequacy of developed software performance

Determining the application’s desired performance characteristics before and after changes to the software.

4) For Improving the efficiency of performance tuning

Analyzing the behavior of the application at various load levels.

Identifying bottlenecks in the application. 

Source : Various Websites