Web API中的（Async＆await）与（没有Async＆await）

Question

I am new with Async and await using C# Programming. In WebAPI, we have created two API Controllers one with Async and await Programming and other is without that. We have done load testing using JMeter and we have got following results.

Users          Sync                                         Async

---

100           No Errors                                    No Errors                             
500           No Errors                                    No Errors                             
750           No Errors                                    Errors - (59.0 %) - 502 Bad Gateway   
763           No Errors                                    Errors                                
764           No Errors                                    Errors                                
765           Errors - (0.13 %) - 502 Bad Gateway          Errors
1000          Errors                                      Errors                                

Can you any please explain/suggest which approach is best or how can we proceed ?

API Code :

GetPersonalDetailsController - Async and await Used

public async Task<IHttpActionResult> GET([FromUri] RequestQueryListDTO objAPIRequest)
{
    DateTime startResponseTime = DateTime.Now;
    Response objResponse = null;
    string strResponse = string.Empty;
    var HeaderType = Request.Content.Headers.ContentType;
    ProductBAL objProductBAL = null;
    try
    {
        if (objAPIRequest != null)
        {
            Task<Response> tskGetProductDetails = Task<Response>.Run(() =>
            {
                objProductBAL = new ProductBAL();
                return objProductBAL.GetProductDetails(objAPIRequest);

                //Business Access Layer Logic calling
            });
            objResponse = await tskGetProductDetails;
        }
        else
        {
            objResponse = new Response();
            objResponse.ReturnCode = -1;
            objResponse.ReturnMessage = "Missing Parameters.";
        }
    }
    catch (Exception ex)
    {
        \\ Exception Logging
    }
    finally
    {
        objProductBAL = null;
    }
    objResponse.ResponseTime = Math.Round((DateTime.Now - startResponseTime).TotalMilliseconds).ToString();
    if (objResponse.ReturnCode == Convert.ToInt32(General.ReturnCode))
    {
        return Content<Response>(HttpStatusCode.BadRequest, objResponse);
    }
    else
    {
        return Ok(objResponse);
    }
}

========================================================================

GetPDPController - Without using Async and await

public IHttpActionResult GET([FromUri] RequestQueryListDTO objAPIRequest)
{
    DateTime startResponseTime = DateTime.Now;
    Response objResponse = null;
    string strResponse = string.Empty;
    var HeaderType = Request.Content.Headers.ContentType;

    try
    {
        if (objAPIRequest != null)
        {
            //Business Access Layer Logic calling
        }
        else
        {
            objResponse = new Response();
            objResponse.ReturnCode = -1;
            objResponse.ReturnMessage = "Missing Parameters.";
        }
    }
    catch (Exception ex)
    {
        // Exception Logging Code
    }
    finally
    {
        objProductBAL = null;
    }
    objResponse.ResponseTime = Math.Round((DateTime.Now - startResponseTime).TotalMilliseconds).ToString();
    if (objResponse.ReturnCode == Convert.ToInt32(General.ReturnCode))
    {
        return Content<Response>(HttpStatusCode.BadRequest, objResponse);
    }
    else
    {
        return Ok(objResponse);
    }
}

Answer 1

My suggestion is have two methods, one Async and one not. That way you can test more.

• GetProductDetails
• GetProductDetailsAsync

you would then need to change the signature of the calling method aka GET

public IHttpActionResult GET([FromUri] RequestQueryListDTO objAPIRequest)
{
    var objResponse = new Response();

    //check the properties of objAPIRequest
    if(bad)
    {
        //add stuff if you want
        return Content<Response>(HttpStatusCode.BadRequest, objResponse);
    }

    //Business Access Layer Logic calling
    //-----------------------
    ProductBAL objProductBAL = new ProductBAL();

    //you need to change this to async
    var productDetails = objProductBAL.GetProductDetails(objAPIRequest);
    //-----------------------

    return Ok(objResponse);
}