Performance Testing Overview

What is Performance Testing & Monitoring?

PERFORMANCE TESTING checks the speed, response time, reliability, resource usage, scalability of a software program under their expected workload. The purpose of Performance Testing is not to find functional defects but to eliminate performance bottlenecks in the software or device.

The focus of Performance Testing is checking a software program’s

  • Speed – Determines whether the application responds quickly
  • Scalability – Determines maximum user load the software application can handle.
  • Stability – Determines if the application is stable under varying loads

PERFORMANCE MONITORING involves watching the systems, servers and infrastructure of the application when the testing is under process. Monitoring plays a key role during performance testing wherein the load subjected on the application may degrade the performance of the system. Issues related to actual memory, network bandwidth and CPU cycles are resolved using monitors

What is the need of Performance Testing?

Features and Functionality supported by a software system is not the only concern. A software application’s performance like its response time, reliability, resource usage and scalability do matter. The goal of Performance Testing is not to find bugs but to eliminate performance bottlenecks.

Performance Testing is done to provide stakeholders with information about their application regarding speed, stability, and scalability. More importantly, Performance Testing uncovers what needs to be improved before the product goes to market. Without Performance Testing, software is likely to suffer from issues such as: running slow while several users use it simultaneously, inconsistencies across different operating systems and poor usability.

Performance testing will determine whether their software meets speed, scalability and stability requirements under expected workloads.

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Types of Performance Testing

  • Load testing – checks the application’s ability to perform under anticipated user loads. The objective is to identify performance bottlenecks before the software application goes live.
  • Stress testing – involves testing an application under extreme workloads to see how it handles high traffic or data processing. The objective is to identify the breaking point of an application.
  • Endurance testing – is done to make sure the software can handle the expected load over a long period of time.
  • Spike testing – tests the software’s reaction to sudden large spikes in the load generated by users.
  • Volume testing – Under Volume Testing large no. of. Data is populated in a database and the overall software system’s behavior is monitored. The objective is to check software application’s performance under varying database volumes.
  • Scalability testing – The objective of scalability testing is to determine the software application’s effectiveness in “scaling up” to support an increase in user load. It helps plan capacity addition to your software system.

Common Performance Problems

Most performance problems revolve around speed, response time, load time and poor scalability. Speed is often one of the most important attributes of an application. A slow running application will lose potential users. Performance testing is done to make sure an app runs fast enough to keep a user’s attention and interest. Take a look at the following list of common performance problems and notice how speed is a common factor in many of them:

  • Long Load time – Load time is normally the initial time it takes an application to start. This should generally be kept to a minimum. While some applications are impossible to make load in under a minute, Load time should be kept under a few seconds if possible.
  • Poor response time – Response time is the time it takes from when a user inputs data into the application until the application outputs a response to that input. Generally, this should be very quick. Again if a user has to wait too long, they lose interest.
  • Poor scalability – A software product suffers from poor scalability when it cannot handle the expected number of users or when it does not accommodate a wide enough range of users. Load Testing should be done to be certain the application can handle the anticipated number of users.
  • Bottlenecking – Bottlenecks are obstructions in a system which degrade overall system performance. Bottlenecking is when either coding errors or hardware issues cause a decrease of throughput under certain loads. Bottlenecking is often caused by one faulty section of code. The key to fixing a bottlenecking issue is to find the section of code that is causing the slowdown and try to fix it there. Bottlenecking is generally fixed by either fixing poor running processes or adding additional Hardware. Some common performance bottlenecks are
    • CPU utilization
    • Memory utilization
    • Network utilization
    • Operating System limitations
    • Disk usage

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