Importance of Performance testing in software development

In software development arena, there is a mammoth role of performance testing. Performance testing is continual process during the life cycle of the project. It is a combined technical effort of testers, and developers to run and maintain the application to its performance prospects. Performance testing requires high level skill set which includes writing test scripts, watching and appraising test results, modifying the application and restating the process.

Simply elaborated, performance testing is a procedure to determine the responsiveness, reliability, throughput, interoperability, and scalability of a system or application under a given workload. It also assesses the speed and effectiveness of system. System can be a computer, network, software program, or device. Performance testing can be conducted on software application, system resources, targeted applications components, and databases.  In this process, quantitative tests are conducted in a lab, for example measuring the response time or the number of MIPS (millions of instructions per second) at which a system operates. Factors that govern performance testing are throughput, response time, turning, and benchmarking.

Software professionals can successfully develop a product functionally. Professionals cannot check how the product will react in production or live environment. Ignorance of performance testing can also lead to crashing of system. Crashing or lowering performance of system will lead to reduce in product’s immersion on clients and finally slowdown in market growth. Thus, it’s important to have performance testing. Performance testing serve as a diagnostic tool in determining bottlenecks and single point of failure. It is often conducted in controlled environment and in conjecture with stress testing, a process of determining the ability of a system to maintain certain level of effectiveness under unfavorable conditions. .

Major grounds for using performance testing:

-       It Identifies problems early on before they become costly to resolve.

-       Performance testing reduces development cycles.

-       It produces high quality, more scalable code.

-       It averts revenue and credibility loss due to poor Web site performance.

-       Permits intelligent planning for future development.

-       Performance testing ensures that the system meets performance expectations such as response time, throughput etc. under given levels of load.

-       It exposes bugs that do not surface in cursory testing, such as memory management bugs, memory leaks, buffer overflows.

Types of performance testing:

1. Load Testing: As the name denotes in this type of testing, how much load can be handled by system is evaluated. Above the threshold level of load, system can behave in abnormal way. The main purpose of load testing is to check system with continually increasing the load on the system until the time load reaches to its threshold value. Increasing load denotes to growing number of concurrent users, transactions and check the behavior of application under test. It is also known as “Endurance testing” and “Volume testing”. The basic function of load testing is to observe the response time and staying power of application when system is efficiently operating under heavy load. It evaluates the capability of a load balancer and identifies concurrency issues. For example, testing a word processor by editing huge document.

2. Stress Testing: Stress Testing is a type of performance testing to check the steadiness of software when hardware resources are not adequate such as CPU, memory, disk space. Stress testing mainly determines or validates an application’s behavior when it is pushed beyond normal or peak load conditions. Its purpose is to ensure that the system fails and recovers elegantly. For instance, double the baseline number for concurrent users/HTTP connections.

3. Spike testing: Spike testing is subsection of Stress Testing. A spike test is done to authenticate the performance traits when the system under test is exposed to workload models and load volumes that constantly increase beyond expected production operations for short periods of time. It is performed by sudden increase or decrease in load and observing the behavior of load.

4. Soak testing: Soak testing checked with an expected amount of load over a long period of time to comprehend the behavior of system.

5. Scalability Testing: Scalability Testing is the testing of a software application for assessing its capability to scale up in terms of any of its non-functional capability like the user load supported, the number of transactions, and the data volume.

6. Volume testing: Volume testing denotes to testing a software application with huge data to be processed to check the efficiency of the application. The main aim of this testing is to monitor the performance of application under variable database volumes.

Performance testing covers following areas:

-       Assessing application and system production readiness.

-       Evaluating against performance criteria.

-       Comparing performance characteristics of multiple systems.

-       Identifying source of performance bottlenecks.

-       Aiding with performance and system tuning.

-       Helping to identify system throughput level.

-       Testing tool

One of the best tools capable of doing Performance testing according to many testers is Apache Jmeter. It almost covers all types of servers such as web, SOAP, database, LDAP, JMS, mail and shell scripts.

There are numerous challenges of performance testing for software development. These are infrastructure setup, collection and analysis of huge data, identifying the root cause of issues, team effort required, accuracy of results, client involvement, testing inside the firewall, multidimensional application (Web, SAAS, Mobile), testing on live server,  and huge expense.

To bind up, performance testing is usually a collaborative effort between all parties involved in software development. Performance testing appraise the response time, throughput and utilization of system to perform its necessary functions in comparison with different versions of the same product or a different competitive product.