NETCORE performance troubleshooting

One 、 Performance check

• The concept of performance

  Performance comes from the system .

  The system is divided into two categories ：web System 【BS】 And the client 【 desktop 】 System 【CS】.

• Performance indicators are based on

  Two bases ：

  1. Number Number of client execution interfaces , That is to say 1 How many request interfaces can be executed per second , The more you deal with , The higher the performance .

  2. Time The time from the client request to the server and respond to the request is called Performance time ; The shorter the time, the higher the performance .

     Pictured ：

  

  Time and quantity are contradictory ： The shorter the time, the greater the number of executions 【 throughput 】, The longer the time, the less the number of executions .

  The starting point of performance is the execution time of an interface .

• Get the execution time of the system interface

  Tools ：

  1. Apche JMeter 【 Commonly used 】
  2. ApcheBench（ab） Command line tools 【 Commonly used 】
  3. Gatling
  4. K6
  5. Locust
  6. West Wind WebSurge
  7. Netling
  8. Vegeta
  9. NBomber

• Performance diagnostics

  • Tools

    1. VS Built in performance detector

  • CPU The reasons for the rise in usage

    1. while for loop

       Solution ： Use Hash Table search stores data

    2. File operations

       Solution ： asynchronous IO DoNetty

    3. Network connection and network data transmission

       Solution ： Use caching to store data perhaps Use asynchronous IO Multiplexing mechanism

       CPU The defect of increasing utilization ：

       The ability to handle interface concurrency decreases

       The throughput of the system decreases

• Performance troubleshooting

  • Conditions

    • NET CORE 3.1 SDK or More advanced version
    • dotnet-counters Check managed memory usage
    • dotnet-dump Collect and analyze dump files

  • step

    1. Create a memory overflow item

    2. install dotnet-counters Get ready

       dotnet tool install --global dotnet-counters
       

    3. Find the process number

       dotnet-counters ps
       

    4. Monitor progress

       dotnet-counters monitor --refresh-interval 1 -p [ Process number ]
       

    5. Finally, view the display statistics

       find GC Heap Size Count the growth of this program , In order to find out the code of memory overflow .

    6. dotnet-dump install

       dotnet tool install --global dotnet-dump 
       

    7. Then execute the project interface

       Run the project

    8. Generate dump file

       dotnet-dump collect -p [ Process number ]
       

    9. Then analyze the dump file

       dotnet-dump  analyze [ Dump file name ]
       

    10. To analyze

    dumpheap -stat
    

    11. Analyze the specific objects of the type

        dumpheap -mt [ Type number ]
        

    12. Find the application root

        gcroot -all [ Object number ]