Performance Testing

• What is Performance testing

Non Functional Testing
To ensure software applications will perform well under their expected workload. like its response time, reliability, resource usage and scalability
demonstrate that your software system meets certain pre-defined performance criteria. 

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

• 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.Some common performance bottlenecks are CPU utilization,
Memory utilization,Network utilization,Operating System limitations,Disk usage.
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.

• When to do performance testing

Performance Testing is always done for client-server based systems only.

• How to do Performance Testing

• Tools

LoadNinja – is revolutionizing the way we load test. This cloud-based load testing tool empowers teams to record & instantly playback comprehensive load tests, without complex dynamic correlation & run these load tests in real browsers at scale. Teams are able to increase test coverage. & cut load testing time by over 60%.

NeoLoad - is the performance testing platform designed for DevOps that seamlessly integrates into your existing Continuous Delivery pipeline. With NeoLoad, teams test 10x faster than with traditional tools to meet the new level of requirements across the full Agile software development lifecycle - from component to full system-wide load tests.

HP LoadRunner - is the most popular performance testing tools on the market today. This tool is capable of simulating hundreds of thousands of users, putting applications under real-life loads to determine their behavior under expected loads. Loadrunner features a virtual user generator which simulates the actions of live human users.

Jmeter - one of the leading tools used for load testing of web and application servers.