iot/projects/IoTCenter/Services/HealthCheckService.cs

using Application.Domain.Entities;
using Application.Models;
using Infrastructure.Data;
using Infrastructure.Extensions;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace IoTCenter.Services
{
    public class HealthCheckService : IDisposable
    {
        protected readonly IServiceProvider _applicationServices;
        protected readonly IConfiguration _configuration;
        protected CancellationTokenSource _tokenSource;

        public HealthCheckService(IServiceProvider applicationServices, IConfiguration configuration)
        {
            this._applicationServices = applicationServices;
            this._configuration = configuration;
            this._tokenSource = new CancellationTokenSource();
        }

        public virtual void Start()
        {
            Task.Run(async () =>
            {
                while (!_tokenSource.IsCancellationRequested)
                {
                    try
                    {
                        Execute();
                    }
                    catch (Exception ex)
                    {
                        ex.PrintStack();
                    }
                    await Task.Delay(5 * 1000);
                }
            });
        }

        private void Execute()
        {
            using (var scope = _applicationServices.CreateScope())
            {
                var nodeRepo = scope.ServiceProvider.GetService<IRepository<Node>>();
                var nodes = nodeRepo.ReadOnlyTable().ToList();
                var pageHubContext = scope.ServiceProvider.GetService<IHubContext<PageHub>>();
                foreach (var node in nodes)
                {
                    try
                    {
                        pageHubContext.Clients.Group(node.Number).SendAsync(Methods.ServerToClient, Methods.HealthCheckRequest, "", null);
                    }
                    catch (Exception ex)
                    {
                        ex.PrintStack();
                        var tempNode = nodeRepo.Table().FirstOrDefault(o => o.Number == node.Number);
                        tempNode.IsOnline = false;
                        nodeRepo.SaveChanges();
                    }
                }
            }
        }

        public void Dispose()
        {
            this._tokenSource.Cancel();
        }
    }
}