Summary of "performance test" of special test

1、 Performance test concept

Virtual user 】 Virtual users simulating real business logic steps , The simulated operation steps are recorded in the virtual user script .

【 Business 】 Transactions are an important feature of performance testing scripts , According to the smallest http Request packaged .

【TPS】 The number of transactions or transactions processed by the system per second .

【PV】 The user browser accesses the page , Every request to the application server , Record a PV.

【Peak PV】 Peak value PV, It is generally applicable to interface test .

【 Concurrent 】 Concurrency is divided into broad and narrow concurrency . Chivalrous concurrency means that all users are at the same time Do the same thing , Generally, it is the same type of business , Or all users can perform the same operation . Generalized concurrency refers to multiple users sending requests or operations to the system , But these requests or operations can be different , For the whole system , There are still many users operating at the same time .

【 scene 】 In order to simulate the processing process of real users during the performance test .

【 response time 】 Response time is when the client sends a request , The time elapsed until the client receives the response result returned by the server .

【 Thinking time 】 Simulate the pause interval of the user's formal actual operation , Thinking time affects TPS.

【CPU resources 】CPU It refers to the time during which the performance test scenario runs , Application server system CPU Resource utilization .

【 Standard deviation 】 The standard deviation is derived from the concept of data statistics , The smaller the standard deviation , It shows that the more stable the system is .

2、 Types of performance tests

【 Performance testing 】 Chivalrous performance test , It refers to the premise of performance expectation , Keep pressure on the system , Verify that the system is within the acceptable range of resources , Whether it can meet the performance expectations .

【Linux Resource view 】
top

top -i  Dynamic display memory 
top  Every time 5 Seconds shows the resource usage 
top -d 2 Every time 2 Seconds displays the resource consumption of the system 

free

free Indicates the memory usage 

iostat(IO)

iostat -d -k 2 -d Indicates the usage status of the disk  -k  Disk usage block  2 Express 2 Once per second 
iostat -d sda 2 Indicates the specified monitoring sda

In memory buffer and cache

 Write cache ： Data storage , Save to disk buffer first , And then write it to permanent space 
 Read cache ： After the data is read from the disk , Stay in the buffer , The next use of the prep program 

【 The load test 】 Chivalrous load test , It refers to the continuous increase of pressure on the system or the duration under a certain pressure , Until one or several performance indexes of the system reach the safety critical value .

【 Pressure test 】 Chivalrous stress test , It refers to the case that the safe load is exceeded , Keep pressure on the system .

【 Stability test 】 Stability test TPS, response time , The fluctuation rate of resource consumption shall not exceed 15%.

3、 Focus on performance testing

【 User perspective 】 response time , User experience . The response time of the performance test and pressure test server is generally in the intranet , Therefore, the response time of the public network is not considered . Stress testing should not be done on the public network , Because the public network environment is uncontrollable .

【 Operation and maintenance 】 Whether the resource consumption is normal , Whether the database planning configuration is normal . The performance monitoring tools for operation and maintenance mainly include zabbix Tools etc. .

【 Development perspective 】 Page performance , Code correctness .

【 Customer perspective 】 System scalability , Project cost .

4、 Performance testing tools

【 Testing tools 】 The mainstream performance testing tools are ：LoadRunner、Jmeter.

【 Scripting language 】Java、Python、Shell etc. .

【 Performance testing related middleware 】tomcat Multithreading 、jetty、jboss、weblogic、web sphere etc. .

【 Common databases 】SQL Server、Oracle、MySQL、Redis、ES Engine, etc .

5、 Performance test indicators

1、 Meet with sufficient resources TPS

2、 The passing rate shall not exceed the safety limit

3、 Resource consumption does not exceed the safety limit

4、 Interface test response time

（1） General interface response time distribution ：

100ms For good

500ms Pass for

1000ms The above is intolerable

（2） Distribution of response time of financial interface ：

100ms For good

200ms Pass for

300ms The above is intolerable

5、 Test the response time of the server

（1）1/3/5 Exclude network time and front-end increase time

（2）2/4/6 Plus network delay , When concurrency is serious 6s

6、 Number of concurrent users and TPS What's the relationship between you and me

（1） It matters , But it's not proportional

（2） It is inversely related to the time of thinking

（3） Network time should be considered , But exclude

7、 When a resource reaches the high-end threshold, it reaches B spot

（1） Generally tested to B Just a little

A The dot is for free time

A-B It is used during peak hours

（2） The stability test is generally carried out in B spot

（3） Optimal number of users B spot

（4） The foundation of never downtime B spot

8、 High end threshold B Point to judge the indicators

（1）CPU 70%

（2） Memory 70%

（3）I/O 60%

（4） The Internet

A network card , Access network card 40%

Two network cards , Network access card 80%, Out of the network card 80%

9、 Low point threshold non peak business value A What are the indicators of

（1）CPU 50%

（2） Memory 50%

（3）I/O 40%

（4） The Internet 30%

10、 Summary of each point of performance test

（1） In the safe value, you want no exchange of virtual memory

（2） How to test inflection point ？ The more you test, the slower the slope will be , To test the real inflection point

（3） Pressure measurement indicates that a certain resource has reached its limit C spot

11、 What is the difference between single scenario and multi scenario testing

（1） The question of whether there are enough resources

（2） The problem of resource allocation

（3） The problem of competing for resources

Finally, I also sorted out some software testing learning materials , It should be very helpful for small partners learning software testing , In order to better organize each module

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