Thursday 26 April 2012

Load Testing

Load Testing:
Load Testing is subset of performance testing. It is done by constantly increasing the load on the application under test till the time it reaches the threshold limit. The main goal of load testing is to identify the upper limit of the system in terms of database, hardware and network etc. The common goal of doing the load testing is to set the SLAs for the application. Example of load testing can be:

Running multiple applications on a computer simultaneously - starting with one application, then start second application, then third and so on....Now see the performance of your computer.
Endurance test is also a part of load testing which used to calculate metrics like Mean Time Between Failure and Mean Time to Failure.
Load Testing helps to determine:
  • Throughput
  • Peak Production Load
  • Adequacy of H/W environment
  • Load balancing requirements
  • How many users application can handle with optimal performance results
  • How many users hardware can handle with optimal performance results
 
Testing with the intent of determining how well the product handles competition for system resources. The competition may come in the form of network traffic, CPU utilization or memory allocation.
Load testing is meant to test the system by constantly and steadily increasing the load on the system till the time it reaches the threshold limit. It is the simplest form of testing which employs the use of automation tools such as LoadRunner or any other good tools, which are available. Load testing is also famous by the names like volume testing and endurance testing.
The sole purpose of load testing is to assign the system the largest job it could possible handle to test the endurance and monitoring the results. An interesting fact is that sometimes the system is fed with empty task to determine the behaviour of system in zero-load situation.
Load Testing Goal:
The goals of load testing are to expose the defects in application related to buffer overflow, memory leaks and mismanagement of memory. Another target of load testing is to determine the upper limit of all the components of application like database, hardware and network etc… so that it could manage the anticipated load in future. The issues that would eventually come out as the result of load testing may include load balancing problems, bandwidth issues, capacity of the existing system etc…
Example:
For example, to check the email functionality of an application, it could be flooded with 1000 users at a time. Now, 1000 users can fire the email transactions (read, send, delete, forward, reply) in many different ways. If we take one transaction per user per hour, then it would be 1000 transactions per hour. By simulating 10 transactions/user, we could load test the email server by occupying it with 10000 transactions/hour.

No comments:

Post a Comment