Fundamentals of performance testing -- definitions of common terms

background ： During the performance test , We will encounter various nouns and indicators , What do you mean .
Purpose ： Reach a consensus to work with you as a performance related person
Networking diagram ： Don't involve
The picture is not clear , Just read the following words

1. Basic concepts of performance testing
What is performance testing
Performance testing is to simulate a variety of normal through automated testing tools 、 Peak and abnormal load conditions to test the performance of the system
2. Classification of performance tests
The load test
Load testing is done by gradually increasing the system load , Test for changes in system performance , And finally determine that under the premise of meeting the system performance index , Test of the maximum load that the system can bear . In short , Load test is to determine the processing capacity of the system and various thresholds that can be borne by the system through step-by-step pressurization . for example , By gradually pressurizing “ The response time shall not exceed 10 second ”、“ Server average CPU Utilization is lower than 85%” Threshold value of other indicators
• Purpose ; Find the limits of the system's processing power
Pressure test
Stress testing is done by gradually increasing the system load , Test for changes in system performance , And finally determine under what load conditions the system performance is in failure state to obtain the maximum service level that the system can provide . The stress test is to gradually increase the load , Make some resources of the system reach saturation or even fail
• Purpose ： Performance of the system under pressure , In fact, more attention is paid to how the system dies
Capacity test
The capacity test is carried out in a certain soft 、 Under hardware conditions , Construct the number of records of different orders of magnitude in the database , By running one or more business scenarios , In the case of a certain number of virtual users , Get different levels of performance metrics , So as to get the maximum session capacity that the database can handle 、 Maximum capacity, etc . The maximum number of users that the system can handle online at the same time , It's usually about databases
Concurrent test
Concurrent testing is to test multiple users accessing the same application at the same time 、 Whether there are deadlock or other performance problems in the same module or data recording , So almost all performance tests involve some concurrent tests . Because it's not \n The test is quite demanding on time , Usually, the simulation of concurrent users is done with the help of tools , Multi thread or multi process mode is adopted to simulate the concurrent operation of multiple virtual users . In the following introduction LoadRunner Tool time , There is a concept of assembly point , It is used to simulate concurrency , Can be in VuGen Set assembly point in , stay Controller Set its corresponding strategy to simulate the scenario of use case design
Marshal Point
It mainly focuses on the concurrency of a large number of users , All users submit a request at the same time , It is a subset of stress testing
Reliability test
Reliability test is to load a certain amount of business pressure on the system （ Such as CPU Resources in 70%～90% The usage rate of ） Under the circumstances , Run for a while , Check whether the system is stable
Verify whether the system can perform stably for a long time
Failed tests
Through the failure test to verify if the system local failure , Can users continue to use the system , How much is the impact on users , For example, several machines do load balancing , The pressure that the system can withstand after one or more machines break down
• Purpose ： Whether the system has disaster tolerance capability
Configuration testing
Configuration test is mainly conducted by testing the software and hardware configuration of the tested software , Find the optimal allocation principle of system resources . Configuration testing can make full use of limited hardware and software resources , Give full play to the best processing capacity of the system , At the same time, it can be combined with other performance test types , So as to provide an important basis for system tuning . topic
• Purpose ： The impact of different configurations on the system
3. Purpose of performance test
The purpose is to verify whether the software system can meet the performance indicators proposed by the user , At the same time, we found the performance bottleneck in the software system , Optimize software , Finally, the purpose of optimizing the system
I think whether the system meets the requirements
4. Common tools for performance testing
jmeter
loadrunner
locust
apache bench
performantest
Other
5. Common terms for performance testing
response time
Evaluate the processing speed of the system from the perspective of users ; For standard web System We usually have one 2,5,10 Principles
TP90
TP95
TP99
Mean response time （AVG）
TPS
Transaction Per second Transaction processing capability is a general concept , We think , Anything , Can be regarded as a transaction
QPS
RPS
throughput
Throughput refers to the total amount of data transmitted on the network during the one-time performance test
Throughput rate
Throughput is the number of bytes returned from the server per unit time , It can also refer to the number of requests submitted by clients processed by the server per unit time , It is an important index to measure the network performance
Throughput rate = throughput / Test time
Number of concurrent users
The number of concurrent users refers to the number of all users who interact with the server at the same time
• In general , You can refer to the following methods to determine the number of concurrent users during performance testing ：
（1） Refer to other similar products .
（2） Analyze historical data .
（3） Commissioning
Resource utilization
Resource utilization refers to the use of different hardware resources in the server system , It mainly includes CPU utilization 、 Memory utilization 、 Hard disk utilization and network . Resource utilization is the main basis for analyzing system performance indicators and improving performance , In the configuration tuning test , By comparing the utilization of system resources before and after tuning, we can judge the tuning results
• Thinking time ： Simulate real scene , Thinking time is not a fixed value , Everyone has a different time ,loadrunner You can set
Performance test scenario analysis
Traditional door shaped scene