在自托管ASP.NET Core微服务中启动多个后台线程

本文介绍了在自托管ASP.NET Core微服务中启动多个后台线程的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我在哪里可以在Self Hosted Self Contained ASP.NET Core Microservice中创建多个长期运行的后台线程，它们的生存期与微服务生存期相同?这样，从线程中检索到的信息就可以作为对请求的响应而发送.

Where can i create multiple long running background threads in Self Hosted Self Contained ASP.NET Core Microservice whose lifetime is same as micro-service lifetime? So that information retrieved from threads can be sent as a response to the requests.

尝试使用给定的代码，但是当后台线程繁忙时，它会降低http请求的性能. Program.cs文件的主要方法是:

Tried given code but it reduces http request performance when background threads are busy. Main method of Program.cs file is:

static void Main(string[] args) { //Start background thread1 //Start background thread2 //Around 10 background threads //Start host var host = new WebHostBuilder() .UseKestrel() .UseUrls(ServerUrl) .UseConfiguration(config) .UseContentRoot(Directory.GetCurrentDirectory()) .UseIISIntegration() .ConfigureServices(s => s.AddRouting()) .Configure(app => app.UseRouter(r => { (new Router()).Route(r); })) .Build(); host.Run(); }

线程以这种方式工作:

Thread t1 = new Thread(StartWork); t1.IsBackground = true; t1.Start(); public void StartWork() { while (ApplicationIsRunning) { //Get database info >> login into remote devices (SSH) >> get information >> process information >> update application variables and database Thread.Sleep(10000); } }

当线程繁忙但http请求性能仍然很差时，CPU利用率仅为1-5％.进入睡眠状态后，性能再次提高.

CPU utilization is only 1-5% when threads are busy but still http request performance is very bad. After going to sleep state performance again improves.

问题出在SSH客户端连接的连接方法上.在某些时候，connect方法没有响应，并且还会影响所有其他线程.真奇怪！

The issue is at connect method of SSH client connection. At some point connect method is not responding and it affect all other threads also. That is strange!

Renci.SshNet.SshClient sshClient = New Renci.SshNet.SshClient(sshConnectionInfo); sshClient.Connect();

如果一个线程由于任何原因忙于连接，则不应影响其他线程.

If one thread is busy in connection because of any reason it should not affect other threads.

推荐答案

代码可能来自史蒂夫·戈登(Steve Gordon)的帖子，网址为 www.stevejgordon.co.uk/asp-net-core-2-ihostedservice 吗?

code possibly from Steve Gordon's post at www.stevejgordon.co.uk/asp-net-core-2-ihostedservice ?

确保您可以:) 使用IHostedService(核心提供的即用型)，您可以实现以下功能:

sure you can :) With IHostedService (out-of-the-box from core) you can implement the following:

public abstract class HostedService : IHostedService { private Task _executingTask; private CancellationTokenSource _cts; public Task StartAsync(CancellationToken cancellationToken) { // Create a linked token so we can trigger cancellation outside of this token's cancellation _cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken); // Store the task we're executing _executingTask = ExecuteAsync(_cts.Token); // If the task is completed then return it, otherwise it's running return _executingTask.IsCompleted ? _executingTask : Task.CompletedTask; } public async Task StopAsync(CancellationToken cancellationToken) { // Stop called without start if (_executingTask == null) { return; } // Signal cancellation to the executing method _cts.Cancel(); // Wait until the task completes or the stop token triggers await Task.WhenAny(_executingTask, Task.Delay(-1, cancellationToken)); // Throw if cancellation triggered cancellationToken.ThrowIfCancellationRequested(); } // Derived classes should override this and execute a long running method until // cancellation is requested protected abstract Task ExecuteAsync(CancellationToken cancellationToken); } then you can implement your abstract class: public class DataRefreshService : HostedService { private readonly RandomStringProvider _randomStringProvider; public DataRefreshService(RandomStringProvider randomStringProvider) { _randomStringProvider = randomStringProvider; } protected override async Task ExecuteAsync(CancellationToken cancellationToken) { while (!cancellationToken.IsCancellationRequested) { await _randomStringProvider.UpdateString(cancellationToken); await Task.Delay(TimeSpan.FromSeconds(5), cancellationToken); } } }

，在您的设置中，您只需添加依赖项:

and in your setup you only have to add the dependency:

services.AddSingleton<IHostedService, DataRefreshService>();

RandomStringProvider只是一个例子.你得到图片了:)

RandomStringProvider is just an example. You get the picture :)

核心自动为您连接，就像一个护身符！保持rabbitmq连接打开的完美之选！

core wires this automatically for you, works like a charm! Perfect to keep a rabbitmq-connection open!

试一试！