Webapi performance optimization

One 、WebApi tuning

• What is? WebApi tuning

  When the browser side requests WebApi It takes time for the server to read and write data , Shorten the time it takes , It's called WebApi tuning .

  Pictured ：

• Purpose
  promote WebApi Performance of .

Two 、WebApi Application scenarios

• scene

  Projects that are separated at the front and rear end .

3、 ... and 、WebApi Performance bottleneck positioning

• Locate performance bottlenecks

  Please have a look at NetCore Performance troubleshooting article ：https://blog.csdn.net/Fu_Shi_rong/article/details/123733415?spm=1001.2014.3001.5501

Four 、WebApi Performance optimization means 1 - Local cache

• Single project

  Pictured ：

• Realization

  • Design thinking

    When querying, first check whether there is data in the local cache , There's data coming back directly , Query the database when there is no data , Add the queried data to the local cache and return the data to the browser

  • Advantages and disadvantages

    • shortcoming

      Memory Is the cache in the server memory , If the concurrency is large and the query data is inconsistent , It will cause a very large memory , At the same time, it will cause GC Constantly reclaim this memory , because Memory Memory cannot be recycled due to static variables used internally ,GC Every time you recycle , It will consume once CPU resources , If GC The frequency of recycling is relatively high , That consumes CPU Resources will also grow , for example ： current CPU The usage rate of is 100%,GC consumed 70%CPU resources , Then our throughput is only 30%, The performance of processing requests is greatly reduced .

      • Solution
        1. Use time for space to solve , Set the cache time .
        2. Set cache size
        3. Set the size of a single cache , And set the automatic expiration time

    • advantage

      Data reading and writing speed and time are reduced , Improved performance .

• Implementation steps

  • Install cache Nuget package

    Microsoft.Extensions.Caching.Memory  
    

  • Startup register

    ConfigureServices Method 
    Service.AddMemoryCache(options=>{
       options.SizeLimit = 1024*1024*100; // Set cache size 
    });
    

  • Inject in the scene of use

     Inject... Into the construction method 
    
    private readonly IMemoryCache memoryCache;
    
     Constructors   （IMemoryCache _memoryCache）
    {
      
     memoryCache =_memoryCache;
    }
    // Test object  
     Person per = new Person();
    // Query cache method  
    //memoryCache.Get<Person>(key); 
    // To prevent multithreading concurrency 
    bool flag = memoryCache.TryGetValue< Cache object >(key,out per);
    //true： There's data   false： No data 
    // Limit cache size 
    var  cacheEntryOptions = new MemoryCacheEntryOptions（）.
    // Set the size of a single cache 
    SetSize(1024).
    // Set expiration time    Automatic failure 
    SetSlidingExpiration(TimeSpan.FromSeconds(3));
    // Add cache 
    memoryCache.Set<Person>(key,value,cacheEntryOptions);
    

• Solving the first request takes time

  When the project starts , Add data from the database to the cache

  • Code implementation

    // Class inheritance  IHostService  
    // And in Startup Class registration 
    

5、 ... and 、WebApi Performance optimization means 2 - Distributed cache

• programme
  • Please read this article .https://blog.csdn.net/Fu_Shi_rong/article/details/123930343?spm=1001.2014.3001.5501

6、 ... and 、WebApi Performance optimization means 3 -Http cache （ Response cache ）

• programme

  • Negotiate the cache

    • install Nuget package

      Marvin.Cache.Headers
      

    • stay Startup Class only register

      ConfigureServices Method registration 
      Service.AddHttpCacheHeaders((options)=>{options.MaxAge = ....;// Set expiration time    Default 60s
                                              options.CacheLocation = ....;//public   Public   private   Private can only be used by the current client 
                                              options.NoStore= ...;//   Set response header information     No local cache 
                                              options.NoTransform= ....;// Set the request header information  
                                              },
                                  (options1)=>{}); 
      Configure Method to start and store verification information 
      app.UseHttpCacheHeaders();
      

    • Add code to the controller method

      HttpContext.Response.Headers.Add("cache-control","max-age=60,public"); // Whether to enable buffered data storage    Set cache time  
      HttpContext.Response.Headers.Add("etag",Value);// check 
      HttpContext.Response.Headers.Add("last-modified","Mon,24 Dec 2022 09:49:49 GMT");
      

    • principle

      When the client first requests the server , After the server responds , The server will write two parameters to the response header 【1、 Whether to enable cache storage data 2、 check 】 And store it to the client , The client will store the data in the cache warehouse ; When the client requests the server for the second time , Will etag Send it to the server for verification , If two etag They are equal. , The server will return to the client 304, The client will get data from the cache Repository .

    • scene

      Immutable data use .

    • defects

      It will waste a lot of client and server interaction .

• Mandatory cache [ Not commonly used ]

  • step

    • install Nuget package

      Marvin.Cache.Headers
      

    • stay Startup class ConfigureServices Method registration

      ConfigureServices Method registration 
      Service.AddHttpCacheHeaders((options)=>{
        options.MustRevalidate = true;  // In a global way    Not recommended 
      }); 
      Configure Method to start and store verification information 
      app.UseHttpCacheHeaders();
      

    • Add code to the controller method

      HttpContext.Response.Headers.Add("cache-control","max-age=60,public,must-revalidate");
      

    • Use... For a controller

      // Add a property to the controller method 
      [HttpCacheExpiration(CacheLocation = CacheLocation.Public,MaxAge=60)]   Set up NoStore = true   Don't walk the cache 
      [HttpCacheValidation(MustRevalidate = true)]
      

  • scene

    1. Dictionary data
    2. Static resources Pictures, etc
    3. js or css file ​

7、 ... and 、WebApi Performance optimization means 4 - data compression （ Respond to ）

• step

  • stay Startup class ConfigureServices Method registration

    // Response data compression 
    services.AddResponseCompression();
    

  • stay Startup class Configure Method

    // It must be written at the beginning of the middleware 
    app.UseResponseCompression();
    

• The purpose of data compression

  When data is transmitted , Reduce transmission bandwidth , Lifting performance .

• scene

  Data compression can be used whenever data transmission is involved .