It's 2022, and you still don't know what performance testing is?

hi , Friends who are interested in software testing , You must all want to know why the monthly salary of performance test engineers is higher ？ below , Let me tell you more about it ~

First , Software testing is mainly divided into ： A functional test 、 Performance testing 、 automated testing 、 Ease of use test 、 Compatibility test 、 Six categories of reliability testing .

secondly , The average salary of various test engineers varies . According to the third party platform 《 Working friends 》 Employment data analysis , Among the more than 10000 software test engineers in Shanghai , The average salary is 10400 element , The average salary of functional test engineer is 11950 element , The average salary of performance test engineer is as high as 14970 element . Than the average salary of software development engineers 14040 element , And nearly a thousand yuan more .

below , Let's learn about performance testing ~

1、 Performance test content

1） The load test （load test）： For distributed networks , Test the response of the system by testing the number of different users , Focus on performance indicators , The system behaves differently .

2） Pressure test （stress testing）： Multi user high concurrency test under high voltage （30 ten thousand -50 ten thousand ）, Focus on how the system crashed .（ Memory leak ,cpu No response , Database unresponsive , Network congestion ）

3） Capacity test （volumn testing）： The relevant number of maximum supports of the system , The maximum number of data in the database , Number of users .

2、 Why do performance tests ？

1） At present, most applications are distributed applications based on network , We don't know the number of users , Uncertainty of user scenarios , Cause system testing , It's not just function , Business logic , The interface test , Also test the system performance . One user is OK , But once there are many users, there may be various problems , Therefore, system performance test is required .

2） The number of users has increased , System liabilities increased , Conduct system performance test , Know the number of concurrent users the system bears , Whether the bandwidth is enough ,cpu Is it enough for , Is there enough memory , Whether the hard disk speed can keep up with . From the server side , Test whether the server can host multiple concurrent users , Is the system stable , From the user's point of view, response time and speed .

3、 Performance test evaluation index

1） response time （response time）： Evaluate the response speed of the system from the perspective of users , The empirical value of the usual response time ：2s Fluent ,5s You can use ,10s slower .

2） throughput / rate ： Hard disk IO（ Reading and writing ）, The Internet IO（ Uplink and downlink bandwidth ）,cupIO, Server processing power , The number of pages opened by the client .

3） Transaction processing power （TPS tansaction per second)： Open the page , Login server , A certain action of a user, such as message sending, is called a thing .

4、 Performance testing concerns （ It is also the focus of software testing ）

1） The role and value of software testing ： There are two aspects: products and users . Product perspective ： Find problems as early as possible in the R & D process , Improve software quality , Ensure product interaction , Functional perfection , Stable and reliable . User perspective ： Focus on user experience , operation , Interface , performance , Try to improve the user experience as much as possible , Continuous improvement .

2） The focus of performance testing ：（ Three layer architecture , Various constraints , Using clusters , Cloud computing , virtualization ）

Response time is fast or slow , Server side processing speed ;

Server side usage ;

Resource usage on the database side ;

Maximum number of user visits ;

The maximum number of services processed at the same time ;

Examine whether the system can support 7x24 Hour run ;

Memory resources 、 Whether thread resources can be recycled normally ;

Code , Algorithm ,sql Whether the sentence design is reasonable ;

Stability of the whole system , Recoverability .

5、 The core principle of performance testing and the development of testing tools

The core principle of performance testing and the development of testing tools , Mainly based on the first two points ：

1） Based on the agreement （ Front end and back end communication mechanism ）、 Interface （ Decide to interact with the front end ） And code （ Back end ）. Network based distributed architecture ： Simulate users to send requests based on network protocols .

2） Multithreading ： Simulate multithreaded operation 、 Many people operate at the same time 、 Simulate large load （ Functional testing is used to test functions ）.

3） Simulate real scene ： Real network environment , User operation time uncertainty , Operation is uncertain , The data are accurate , Wrong scene , Data may not be available .

6、 Code implementation performance testing

Performance test for a function , Forum login and posting （post agreement , Multithreading these two points ）; Login operation , Post operation （ It's about the agreement ）, Use multithreading to operate at the same time .

7、loadrunner Use （ Protocol script , Multithreading ）

Four main components ：

1）vuser generator ( Virtual User Generator ) Develop performance test scripts ;

2）controller Provide multithreading, concurrency and other operations ;

3）ananlysis Result analysis ;

4）load generator Load generator （controller A primary key inside ）.

for instance ：

A、 Create a new script ：

B、 Enter interface , Click on start Record a script ：

C、internet application refer to b-s framework ,win 32 Refer to c-s framework , The default is to record to action, Check recond Start immediately .

TIPS：

1） You can write it by hand , Can record ：

Click on web_url, Use get request ;

Click on web_submit_data, Use post request .

2） Solve the mess ：

At the beginning of the ：tool > advaced > support charset // utf-8 Or native code ;

Runtime ：vuser > preferences > option > convert from/to utf-8.

3） The difference in coding ：

National standard GB-x ,2byte-16bit , 2^16 Combinations of , Code only Chinese .

utf-8 ：3byte = 24bit 2^24 Combinations of , Unified coding of characters all over the world .

ascii code ： A byte （2^8=128)

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Learning resource sharing

Finally, thank everyone who reads my article carefully , Watching the rise and attention of fans all the way , Reciprocity is always necessary , Although it's not very valuable , If you can use it, you can take it

These materials , For those engaged in 【 software test 】 For our friends, it should be the most comprehensive and complete war preparation warehouse , This warehouse also accompanied me through the most difficult journey , I hope it can help you ！ Everything should be done as soon as possible , Especially in the technology industry , We must improve our technical skills . I hope that's helpful …….