Everything you Need to Know About Performance Testing

Everything you Need to Know About Performance Testing

Performance testing is leveraged to analyze the speed, stability, response time, scalability, reliability, and resource usage of software applications under a particular load. It helps in identifying and eliminating performance bottlenecks of a software application.

Performance testing majorly focuses on checking the following points in a software program:

  • Response time of application to identify the speed of an application
  • Identify maximum user load the app can handle
  • Find out whether the application is stable under different load conditions

Types of Performance Testing – 

1. Load Testing

It helps in checking the application’s capability to perform efficiently under the desired user load. It can help in identifying performance bottlenecks before the application goes into production.

2. Stress Testing

It includes testing applications under extreme loads to observe how it behaves while handling high traffic and data processing. It helps in identifying the breaking point of an app.

3. Endurance Testing

It is done to ensure that the software is capable of handling the expected load over a longer period of time.

4. Spike Testing

It helps in testing the software’s reaction to an abrupt spike in the load generated by an increased number of users.

5. Volume Testing

It includes populating large volumes of data in a database to monitor overall system behavior. It helps in gauging the performance of software under varying database volumes.

6. Scalability Testing

You can use it to determine the effectiveness of an application in “scaling up” to support increased user load. It is used to plan capacity addition to the software system.

Common Performance Problems

The majority of performance testing issues are around poor scalability, response time, speed, or load time. Speed is considered one of the most crucial attributes of an app. A slow app can lose users and bring disrepute to the business. Performance testing helps in ensuring that the app is running at the desired speed for greater customer satisfaction.

Here are a few worth noting common performance problems and how speed is a common issue among some of them.

1. Long Load Time

Load time is known as the initial time taken by the application to start. This should be kept minimal to ensure a better user interface. Some apps may not keep load time under a minute, however, you should always try to keep it under a few seconds.

2. Poor Response Time

It is the time taken by the application from when input is given by the user until the application is able to send the output as a response. It should be very quick otherwise it can slow down your app.

3. Poor Scalability

Poor scalability includes the inability of a software product to handle an expected number of online users. Load testing must ensure that the application is ready to handle a certain number of users.

4. Bottlenecking

Bottlenecks are hurdles in the software system that can affect the overall performance of the system. It happens when either hardware issues or coding errors decrease the throughput under certain loads. It often happens due to a single faulty section of the code. It is efficient to identify and fix the faulty code section causing the slowdown.

Here are a few common performance bottlenecks:

  • CPU utilization
  • Network utilization
  • Memory utilization
  • Operating System limitations
  • Disk usage

Performance Testing Process

Performance testing methodology can vary widely but its object largely remains the same. It can help in identifying whether the software system is meeting all the pre-defined performance criteria or not. It can also help in comparing the performance of multiple software systems or identify the parts of a system impacting the performance.

Here are the steps involved in the performance testing process.

1. Identify Your Testing Environment

It is essential to know the production environment, physical test environment, and the availability of performance testing tools. Understand all the details of the software, hardware, and network configuration you would use to run the test. It can help in identifying potential challenges beforehand and run tests more efficiently.

2. Identify the Performance Acceptance Criteria

It includes constraints and goals for response time, resource allocation, and throughput. It is also crucial to find out the project success criteria outside of these constraints and goals. Test engineers should be able to set goals and performance criteria because project specifications often do not include a wide variety of benchmarks. You can also find a similar application for comparison to set the right performance goals.

3. Plan and Design Performance Tests

Find out how usage will differ among end-users. Identify key scenarios that you can test for all the possible use cases. It is essential to plan performance test data, simulate a variety of end-users, and outline metrics or data to be gathered.

4. Configuring the Test Environment

Arrange all the required resources, tools, and prepare the test environment before execution.

5. Implement Test Design

Create performance tests as per your test design.

6. Run the Tests

Execute and monitor your performance tests.

7. Analyze, Tune and Retest

Analyze, consolidate and share test results. You need to fine-tune and test it again to find out the difference in performance. Normally, improvements tend to get smaller with each test, hence, stop testing when bottlenecking happens by the CPU. 

Performance Testing Metrics: Parameters Monitored

Here are the basic parameters that you should monitor during performance testing:

  • Processor Usage – Amount of time taken by the processor to execute non-idle threads
  • Memory Use – Availability of physical memory to process on a machine
  • Disk Time – Times when the disk is busy executing writing or reading requests
  • Bandwidth – Reflects bits per second leveraged by the network interface
  • Private Bytes – Number of bytes allocated by the process that you can’t share with other processes. They are used to calculate memory usage and leaks
  • Committed Memory – Virtual memory used
  • Memory Pages – The number of pages read from or written to the disk to resolve hard page faults
  • Page Faults – Overall rate at which the processor processes fault pages. It happens when the process needs code out of its working set
  • CPU Interrupts Per Second – It is the average number of hardware interruptions a processor is processing per second
  • Disk Queue Length – Average number of read and write requests for a selected disk during the sample interval
  • Network Output Queue Length – It is the length of the output pack queue in packets. A delay of more than two is considered a delay
  • Network Bytes Total Per Second – It is the rate at which bytes are received and sent on the interface
  • Response Time – Time from when the user enters the input request to until the output is received from the app
  • Throughput – Rate at which the network or computer receives the requests per second
  • Amount of Connection Pooling – Number of user requests met by the pooled connections. The requests connection in the pool can meet, the better the performance is
  • Maximum Active Sessions – Maximum number of sessions that can stay active simultaneously
  • Hit Ratio – It is the number of SQL statements handled by the cached data. It helps in solving bottleneck issues
  • Hits Per Second – Number of hits on the web server per second of load test
  • Rollback Segment – Amount of data that can be rolled back at any time
  • Database Locks – Monitor locking of databases and tables for tuning
  • Thread Counts – You can measure the health of the application by the number of thread running and currently active
  • Garbage Collection – It returns unused memory back to the system. You should monitor it to measure the efficiency

Performance Test Cases Examples

  • Make sure response time is not over 4 second when 1000 users are using the website simultaneously
  • Identify the response time is in the acceptable range in slow network connectivity
  • Check out the maximum number of users an app can handle
  • Identify the data execution time 600 record are written or read simultaneously
  • Check memory and CPU usage of the app and database servers under peak loads
  • Endurance 

Apart from the above-mentioned points, you need to verify the response time of the app under normal, low, moderate, and heavy load conditions. During the real performance testing conditions, you should replace vague terms including heavy load, acceptable range, and more with concrete numbers. Performance engineers should set these numbers as per the requirements of the business and technical architecture of the application.

In Summary

Performance testing has various facets that play an equal part in enhancing the performance of any application. It is essential to follow the due process judiciously to get desired results.

QA InfoTech offers end-to-end performance testing services that help you launch reliable and scalable applications at a faster pace cost-efficiently. Talk to our experts now to explore possibilities.

About the Author

QA InfoTech

QA InfoTech

Established in 2003, with less than five testing experts, QA InfoTech has grown leaps and bounds with three QA Centers of Excellence globally; two of which are located in the hub of IT activity in India, Noida, and the other, our affiliate QA InfoTech Inc Michigan USA. In 2010 and 2011, QA InfoTech has been ranked in the top 100 places to work for in India.

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