Why do we need performance testing and need LoadRunner

What is a feature:

function According to my understanding is software implementation requirements, provide services, then functional testing is to meet the needs of the customer is consistent with the given requirements, that is, the expected results

What is performance:

function is to realize the demand, provide service, then the performance can be understood as the good or bad service. For example, there are two fast-food restaurants, they can provide the demand for serving, then the performance refers to the provision of the meal is quick, whether delicious, or two of the same software to provide login, a login time of 1s, another login time of two seconds, then it is obvious that the first login software performance is better. So we conduct performance tests and also identify whether a service provided by a software is good or bad

Whether to test the function or the performance first:

In the practical application, we usually test the function before performing the performance test, because if you can not realize the function of a single user, how to do hundreds of thousands of user actions

Why use LoadRunner:

We assume a scenario, now there is a booking system, I need to test whether it supports 100 people at the same time booking, if I do not use LoadRunner, pure manual operation, I need 1011 people and 100 computers, one of them under the instruction, the other 100 people at the same time booking. Can you imagine this kind of testing method is expensive, if you want to test whether to support 10,000 users at the same time booking, do I have to prepare 10,000 computers?

LoadRunner This software can simulate the above scenes, only need a computer, a person.

LoadRunner three main components: Virtual User Generator, Controller, analysis

Virtual User generator: Through multi-threaded or multi-process generation dummy users, corresponding to the above example is, LoadRunner can through this component, using multi-threaded or process simulation 100 users

Controller: The commander of the above example, this component allows 100 virtual users to execute simultaneously

Analysis: Collect test results, analyze results

Why do we need performance testing and need LoadRunner