namespace Giants.Services { using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading; using System.Threading.Tasks; using Giants.Services.Core; using Microsoft.Extensions.Configuration; using Microsoft.Extensions.Logging; public class ServerRegistryCleanupService : IServerRegistryCleanupService, IDisposable { private readonly ILogger logger; private readonly IConfiguration configuration; private readonly IServerRegistryStore serverRegistryStore; private readonly IDateTimeProvider dateTimeProvider; private readonly TimeSpan timeoutPeriod; private readonly TimeSpan cleanupInterval; private Timer timer; public ServerRegistryCleanupService( ILogger logger, IConfiguration configuration, IServerRegistryStore serverRegistryStore, IDateTimeProvider dateTimeProvider) { this.logger = logger; this.configuration = configuration; this.serverRegistryStore = serverRegistryStore; this.dateTimeProvider = dateTimeProvider; this.timeoutPeriod = TimeSpan.FromMinutes(Convert.ToDouble(this.configuration["ServerTimeoutPeriodInMinutes"])); this.cleanupInterval = TimeSpan.FromMinutes(Convert.ToDouble(this.configuration["ServerCleanupIntervalInMinutes"])); } public Task StartAsync(CancellationToken cancellationToken) { this.timer = new Timer(this.TimerCallback, null, TimeSpan.Zero, this.cleanupInterval); return Task.CompletedTask; } public Task StopAsync(CancellationToken cancellationToken) { this.timer?.Change(Timeout.Infinite, 0); return Task.CompletedTask; } public void Dispose() { this.timer?.Dispose(); } private void TimerCallback(object state) { this.CleanupServers().GetAwaiter().GetResult(); } private async Task CleanupServers() { List expiredServers = (await this .serverRegistryStore .GetServerInfos(whereExpression: s => s.LastHeartbeat < (this.dateTimeProvider.UtcNow - this.timeoutPeriod))) .Select(s => s.id) .ToList(); if (expiredServers.Any()) { this.logger.LogInformation("Cleaning up {Count} servers.", expiredServers.Count); await this.serverRegistryStore.DeleteServers(expiredServers); } } } }