Performance test overview

Overview of performance testing

One 、 What is performance testing

A kind of software testing , Its main direction is to test the system under a certain load pressure , Response time of the system , throughput , stability , System scalability and other performance indicators .

Find out the problems by combining the architecture and implementation details that should be used , And finally confirm the process of solving the problem .

Most of the performance tests , Is to deploy the program on the server , The performance of the server is measured .

There are also executable programs （APP,exe）--- Client performance

Two 、 Purpose of performance test

1、 Basic purpose

      a、 Verify whether the user's performance indicators are met

      b、 Identify performance bottlenecks in software and optimize

2、 Assess system capabilities

      a、 Load and response time data obtained in the test , Used to verify planned capabilities

      b、 Help make decisions

3、 Identify weaknesses in the system

      a、 The controlled load can be increased to an extreme level , And break through it

      b、 Fix the bottleneck or weakness of the system

4、 System tuning  

      a、 Run the test repeatedly , Verify that the activities of the adjustment system have achieved the expected results

      b、 Improve performance .eg： Long test execution can lead to memory leakage

5、 Verify stability

      Carry out the test under a certain production load for a certain time to evaluate whether the stability and reliability of the system meet the requirements

3、 ... and 、 Performance testing from different perspectives

1、 From the user's point of view ：

      a、 How long do I have to wait ？--- response time

      b、 Why always fail ？--- stability

2、 From the administrator's point of view （ Operations staff ）：

      a、 Is the use of server resources reasonable ？--- Resource utilization

      b、 Is the use of database reasonable ？--- Resource utilization

      c、 Can the system be extended ？--- Extensibility

      d、 How many users can access it at most ？--- System capacity

      e、 Maximum business throughput ？--- System capacity

      f、 What are the potential bottlenecks of the system ？--- Extensibility

      g、 Which equipment to replace , Which machines can be added to improve system performance ？--- Extensibility

       h、7*24 Hours of uninterrupted business access ？--- stability

3、 From a development perspective

      a、 Is the architecture design reasonable ？--- Architecture design

      b、 Is the database design reasonable ？--- Database design

      c、 Is there a performance problem with the code ？--- Code

      d、 Whether there is unreasonable use of memory ？--- Code

      e、 Whether there is unreasonable thread synchronization operation ？--- Code

      f、 Whether there is unreasonable competition for resources ？--- Code

      g、 Whether the code algorithm can be further improved ？--- Code

4、 From the tester's point of view

      a、 The performance in the eyes of testers should be comprehensive

      b、 Include users 、 Development 、 Administrators and other perspectives of performance

      c、 Testers should pay attention to surface phenomena when doing performance tests , Such as response time

      d、 Focus on essence , For example, the utilization rate of server data that users can't see , Is the architecture design reasonable ？ Whether the code is reasonable

5、 Matters of performance test design

      a、 Evaluate the feasibility of the system

      b、 Evaluate the performance index of the system

      c、 Compare the performance characteristics of multiple different systems or different system configurations

      d、 Find out the system performance problems and confirm the root cause

      e、 Do system performance tuning

      f、 Find out the different levels of system throughput

Key indicators of performance test

One 、 response time

      Concept ： The time it takes to respond to a request , It is the main index of users' perception of software performance .

                          

      Response time includes ：

            a、 User client rendering time

            b、 request / Response data network transmission time

            c、 Application server processing time

            d、 Database system processing time

      The response time is reasonable ？

            For one web System , The generally accepted response time standard is 2/5/8 second

           2 It's very good to respond to customers within seconds ,5 It is acceptable to respond to customers within seconds ,8 Seconds is the upper limit of the response that the customer can accept

Two 、 Number of concurrent users

1、 Number of system users ： The total number of users registered in the software system （ Do performance test based on this ）

2、 Number of online users ： Number of users accessed in a certain perspective , These users are just online ; You don't have to do something at the same time

3、 Number of concurrent users ： The number of users who submit requests to the software at the same time in a certain time ; The scene must be the same

3、 ... and 、 throughput

Performance testing ： It refers to the number of requests processed by the system in unit time

From a business perspective ： Throughput can be used ： Number of requests / second 、 Number of pages / second 、 The number of / Days or number of business processed / Hours and so on

From the perspective of network ： Throughput can be used ： byte / Seconds to measure

For interactive applications , Throughput metrics reflect the pressure on the server , It can explain the load capacity of the system

TPS： Transactions per second

Throughput expressed in different ways can account for different levels of problems

In bytes / Second mode ： It means that the number is affected by the network infrastructure 、 Server architecture 、 Application server constraints and other bottlenecks

Number of requests / Second mode ： It is mainly restricted by the application server and application code