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中的并发请求ASP.NETwebapi2的速度几乎是单个请求的六倍

iis-10 concurrency iis asp.net c#

Ogglas · 技术社区 · 6 年前

背景:

我们建了一个React SPA,可以与ASP.NETWeb API 2后端。 NET Framework 4.6.1 . 在初始加载时,我们会发出两个单独的请求来加载数据。在加载大量数据时,我们注意到,当我们在应用程序中发出API请求时,它们都比在Postman中单独尝试请求时慢得多。

原件:

示例结构,fetch当然使用我们的API:

fetch('http://example.com/movies.json')
  .then(function(response) {
    return response.json();
  })
  .then(function(myJson) {
    console.log(JSON.stringify(myJson));
  });

fetch('http://example.com/otherMovies.json')
  .then(function(response) {
    return response.json();
  })
  .then(function(myJson) {
    console.log(JSON.stringify(myJson));
  });

示例C#API方法:

[HttpGet]
[Route("{bsid}/{caseId}")]
public IHttpActionResult GetRenewalCycleForCustomer(string bsid, int caseId)
{
    var customerNumbers = GetCustomerNumbers();

    var userId = HttpContext.Current.User.Identity.GetUserId<int>();

    var user = identityDb.Users.Find(userId);

    var customerNumbers = user.ApplicationUserCustomerNumbers.Select(x => new CustomerNumberKey() { bsid = x.CustomerNumber.bsid, NameNo = x.CustomerNumber.NameNo }).ToList();

    var db = new DbContext();

    var caseService = new CaseService(db);

    var portfolioTabViewModel = caseService.GetPortfolioTabViewModelForCustomer(bsid, caseId, customerNumbers);

    return Ok(portfolioTabViewModel);
}

两个邮递员同时走的例子:

其他注意事项:

我们能做些什么来解决这个问题?

似乎并行运行的非异步方法:

https://stackoverflow.com/a/26737847/3850405

Web.config 这不是我所能做到的。搜索 HttpContext.Current.SetSessionStateBehavior 给出0个结果。

https://stackoverflow.com/a/26172317/3850405

https://serverfault.com/a/800518/293367

https://forums.asp.net/t/2100558.aspx?concurrent+connections+on+windows+pro+10+IIS

更新异步和IIS:

它似乎与async或IIS无关,IIS使用下面的方法测试并发请求。并发的慢请求似乎依赖于其他东西。

异步:

[HttpGet]
[Route("{bsid}/{caseId}")]
public async Task<IHttpActionResult> Get(string bsid, int caseId)
{
    await Task.Delay(3000);
    return Ok();
}

同步:

[HttpGet]
[Route("{bsid}/{caseId}")]
public IHttpActionResult Get(string bsid, int caseId)
{
    Thread.Sleep(3000);
    return Ok();
}

它似乎也不是数据库调用。测试 Include 尽管异步调用的速度要慢得多,但调用的速度是相似的。

[HttpGet]
[Route("{bsid}/{caseId}/async")]
public async Task<IHttpActionResult> GetAsync(string bsid, int caseId)
{
    var db = new DbContext();

    var deviations = await db.RenewalCycles.Where(x => x.Deviations.Any())
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPName))
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPNameType))
        .Include(cycle => cycle.TPCase.GoodsAndServicesDescriptions)
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCaseRelation))
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCountry))
        .ToListAsync();

    return Ok();
}

同步:

[HttpGet]
[Route("{bsid}/{caseId}")]
public IHttpActionResult Get(string bsid, int caseId)
{
    var db = new DbContext();

   var deviations = db.RenewalCycles.Where(x => x.Deviations.Any())
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPName))
        .Include(cycle => cycle.TPCase.CaseNames.Select(caseName => caseName.TPNameType))
        .Include(cycle => cycle.TPCase.GoodsAndServicesDescriptions)
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCaseRelation))
        .Include(cycle => cycle.TPCase.RelatedCases.Select(relatedCase => relatedCase.TPCountry))
        .ToList();

    return Ok();
}

1 回复 | 直到 6 年前

Ogglas 6 年前

最终证明,开销部分与数据库相关。使用的方法 db.Cases.Find(bsid, caseId) Cases 模型反过来又有很多关系,所有这些关系都发出一个单独的数据库调用,因为模型的属性被标记为 virtual public virtual TPRenewalCycle TPRenewalCycle { get; set; } 启用延迟加载。通过查看visualstudio输出窗口(Debug->Windows->Output)并设置如下ApplicationDbContext找到它。

public class ApplicationDbContext : DbContext
{
    protected const string ConnectionStringName = "defaultConnection";
    public ApplicationDbContext() : base(ConnectionStringName)
    {
        Database.Log = s => System.Diagnostics.Debug.WriteLine(s);
        Database.CommandTimeout = 300;
    }