如何强制ASP.NET分别处理用户的请求？

Question

Is it possible to Handle simultaneous user requests respectively in ASP.NET WebApi? I don't want to ignore user request with throttling and I don't want to add user session cause I have User UUID. Due to multi-threading issue I want user request to be added inside a queue and whenever it's previous request finished next one happen.

Edit : I Have an Android app and using retrofit. It's possible that the client send two request at the same time and IIS will handle it in two different threads. I want user request with special UUID be handled respectively in the pipeline and not at the same time.

Edit : I want this in ASP.NET https://camo.githubusercontent.com/ab3d320b740b881b173a7f19b6e02a01326ad1dc/68747470733a2f2f7374726f6e676c6f6f702e636f6d2f77702d636f6e74656e742f75706c6f6164732f323031342f30312f746872656164696e675f6a6176612e706e67

Answer 1

In order to queue up requests from a particular client you could use a named lock:

private readonly ConcurrentDictionary<string, object> lockDict = new ConcurrentDictionary<string, object>();

and then inside your server side handler get the user id and ensure that only a single thread can process it at a time:

void ProcessRequest()
{
    string userId = GetUserIdFromRequest();
    lock (lockDict.GetOrAdd(userId, s => new object()))
    {
        // do the actual processing here and return response to the client.
    }
}

Note however that this approach will only work on a single server environment. If you have server farms you will need to use a distributed named lock implementation instead.

Also note that if you have hundreds of concurrent requests from the same client and those requests take time to execute this will block them up and jeopardize your worker threads on the server eventually impacting other requests.

Personally I would recommend you reviewing your current design and think a little bit more about a stateless architecture.

Answer 2

Your approach is wrong. I think you should use optimistic concurrency control :

Please see bellow link :

https://docs.microsoft.com/en-us/aspnet/mvc/overview/getting-started/getting-started-with-ef-using-mvc/handling-concurrency-with-the-entity-framework-in-an-asp-net-mvc-application