AspNet Core上實現(xiàn)web定時任務(wù)實例
作為一枚后端程序狗,項目實踐常遇到定時任務(wù)的工作,最容易想到的的思路就是利用Windows計劃任務(wù)/wndows service程序/Crontab程序等主機(jī)方法在主機(jī)上部署定時任務(wù)程序/腳本。
但是很多時候,若使用的是共享主機(jī)或者受控主機(jī),這些主機(jī)不允許你私自安裝exe程序、Windows服務(wù)程序。
碼甲會想到在web程序中做定時任務(wù), 目前有兩個方向:
- ①.AspNetCore自帶的HostService, 這是一個輕量級的后臺服務(wù), 需要搭配timer完成定時任務(wù)
- ②.老牌Quartz.Net組件,支持復(fù)雜靈活的Scheduling、支持ADO/RAM Job任務(wù)存儲、支持集群、支持監(jiān)聽、支持插件。
此處我們的項目使用稍復(fù)雜的Quartz.net實現(xiàn)web定時任務(wù)。
項目背景
最近需要做一個計數(shù)程序:采用redis計數(shù),設(shè)定每小時將當(dāng)日累積數(shù)據(jù)持久化到關(guān)系型數(shù)據(jù)庫sqlite。
添加Quartz.Net Nuget 依賴包:<PackageReference Include="Quartz" Version="3.0.6" />
- ①.定義定時任務(wù)內(nèi)容: Job
- ②.設(shè)置觸發(fā)條件: Trigger
- ③.將Quartz.Net集成進(jìn)AspNet Core
頭腦風(fēng)暴
IScheduler類包裝了上述背景需要完成的第①②點工作 ,SimpleJobFactory定義了生成指定的Job任務(wù)的過程,這個行為是利用反射機(jī)制調(diào)用無參構(gòu)造函數(shù)構(gòu)造出的Job實例。下面是源碼:
//----------------選自Quartz.Simpl.SimpleJobFactory類------------- using System; using Quartz.Logging; using Quartz.Spi; using Quartz.Util; namespace Quartz.Simpl { /// <summary> /// The default JobFactory used by Quartz - simply calls /// <see cref="ObjectUtils.InstantiateType{T}" /> on the job class. /// </summary> /// <seealso cref="IJobFactory" /> /// <seealso cref="PropertySettingJobFactory" /> /// <author>James House</author> /// <author>Marko Lahma (.NET)</author> public class SimpleJobFactory : IJobFactory { private static readonly ILog log = LogProvider.GetLogger(typeof (SimpleJobFactory)); /// <summary> /// Called by the scheduler at the time of the trigger firing, in order to /// produce a <see cref="IJob" /> instance on which to call Execute. /// </summary> /// <remarks> /// It should be extremely rare for this method to throw an exception - /// basically only the case where there is no way at all to instantiate /// and prepare the Job for execution. When the exception is thrown, the /// Scheduler will move all triggers associated with the Job into the /// <see cref="TriggerState.Error" /> state, which will require human /// intervention (e.g. an application restart after fixing whatever /// configuration problem led to the issue with instantiating the Job). /// </remarks> /// <param name="bundle">The TriggerFiredBundle from which the <see cref="IJobDetail" /> /// and other info relating to the trigger firing can be obtained.</param> /// <param name="scheduler"></param> /// <returns>the newly instantiated Job</returns> /// <throws> SchedulerException if there is a problem instantiating the Job. </throws> public virtual IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler) { IJobDetail jobDetail = bundle.JobDetail; Type jobType = jobDetail.JobType; try { if (log.IsDebugEnabled()) { log.Debug($"Producing instance of Job '{jobDetail.Key}', class={jobType.FullName}"); } return ObjectUtils.InstantiateType<IJob>(jobType); } catch (Exception e) { SchedulerException se = new SchedulerException($"Problem instantiating class '{jobDetail.JobType.FullName}'", e); throw se; } } /// <summary> /// Allows the job factory to destroy/cleanup the job if needed. /// No-op when using SimpleJobFactory. /// </summary> public virtual void ReturnJob(IJob job) { var disposable = job as IDisposable; disposable?.Dispose(); } } } //------------------節(jié)選自Quartz.Util.ObjectUtils類------------------------- public static T InstantiateType<T>(Type type) { if (type == null) { throw new ArgumentNullException(nameof(type), "Cannot instantiate null"); } ConstructorInfo ci = type.GetConstructor(Type.EmptyTypes); if (ci == null) { throw new ArgumentException("Cannot instantiate type which has no empty constructor", type.Name); } return (T) ci.Invoke(new object[0]); }
很多時候,定義的Job任務(wù)依賴了其他組件,這時默認(rèn)的SimpleJobFactory不可用, 需要考慮將Job任務(wù)作為依賴注入組件,加入依賴注入容器。
關(guān)鍵思路:
①. IScheduler 開放了JobFactory 屬性,便于你控制Job任務(wù)的實例化方式;
JobFactories may be of use to those wishing to have their application produce IJob instances via some special mechanism, such as to give the opportunity for dependency injection
②. AspNet Core的服務(wù)架構(gòu)是以依賴注入為基礎(chǔ)的,利用AspNet Core已有的依賴注入容器IServiceProvider管理Job 服務(wù)的創(chuàng)建過程。
編碼實踐
① 定義Job內(nèi)容:
// -------每小時將redis數(shù)據(jù)持久化到sqlite, 每日凌晨跳針,持久化昨天全天數(shù)據(jù)--------------------- public class UsageCounterSyncJob : IJob { private readonly EqidDbContext _context; private readonly IDatabase _redisDB1; private readonly ILogger _logger; public UsageCounterSyncJob(EqidDbContext context, RedisDatabase redisCache, ILoggerFactory loggerFactory) { _context = context; _redisDB1 = redisCache[1]; _logger = loggerFactory.CreateLogger<UsageCounterSyncJob>(); } public async Task Execute(IJobExecutionContext context) { // 觸發(fā)時間在凌晨,則同步昨天的計數(shù) var _day = DateTime.Now.ToString("yyyyMMdd"); if (context.FireTimeUtc.LocalDateTime.Hour == 0) _day = DateTime.Now.AddDays(-1).ToString("yyyyMMdd"); await SyncRedisCounter(_day); _logger.LogInformation("[UsageCounterSyncJob] Schedule job executed."); } ...... }
②注冊Job和Trigger:
namespace EqidManager { using IOCContainer = IServiceProvider; // Quartz.Net啟動后注冊job和trigger public class QuartzStartup { public IScheduler _scheduler { get; set; } private readonly ILogger _logger; private readonly IJobFactory iocJobfactory; public QuartzStartup(IOCContainer IocContainer, ILoggerFactory loggerFactory) { _logger = loggerFactory.CreateLogger<QuartzStartup>(); iocJobfactory = new IOCJobFactory(IocContainer); var schedulerFactory = new StdSchedulerFactory(); _scheduler = schedulerFactory.GetScheduler().Result; _scheduler.JobFactory = iocJobfactory; } public void Start() { _logger.LogInformation("Schedule job load as application start."); _scheduler.Start().Wait(); var UsageCounterSyncJob = JobBuilder.Create<UsageCounterSyncJob>() .WithIdentity("UsageCounterSyncJob") .Build(); var UsageCounterSyncJobTrigger = TriggerBuilder.Create() .WithIdentity("UsageCounterSyncCron") .StartNow() // 每隔一小時同步一次 .WithCronSchedule("0 0 * * * ?") // Seconds,Minutes,Hours,Day-of-Month,Month,Day-of-Week,Year(optional field) .Build(); _scheduler.ScheduleJob(UsageCounterSyncJob, UsageCounterSyncJobTrigger).Wait(); _scheduler.TriggerJob(new JobKey("UsageCounterSyncJob")); } public void Stop() { if (_scheduler == null) { return; } if (_scheduler.Shutdown(waitForJobsToComplete: true).Wait(30000)) _scheduler = null; else { } _logger.LogCritical("Schedule job upload as application stopped"); } } /// <summary> /// IOCJobFactory :實現(xiàn)在Timer觸發(fā)的時候注入生成對應(yīng)的Job組件 /// </summary> public class IOCJobFactory : IJobFactory { protected readonly IOCContainer Container; public IOCJobFactory(IOCContainer container) { Container = container; } //Called by the scheduler at the time of the trigger firing, in order to produce // a Quartz.IJob instance on which to call Execute. public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler) { return Container.GetService(bundle.JobDetail.JobType) as IJob; } // Allows the job factory to destroy/cleanup the job if needed. public void ReturnJob(IJob job) { } } }
③結(jié)合ASpNet Core 注入組件;綁定Quartz.Net
//-------------------------------截取自Startup文件------------------------ ...... services.AddTransient<UsageCounterSyncJob>(); // 這里使用瞬時依賴注入 services.AddSingleton<QuartzStartup>(); ...... // 綁定Quartz.Net public void Configure(IApplicationBuilder app, Microsoft.AspNetCore.Hosting.IApplicationLifetime lifetime, ILoggerFactory loggerFactory) { var quartz = app.ApplicationServices.GetRequiredService<QuartzStartup>(); lifetime.ApplicationStarted.Register(quartz.Start); lifetime.ApplicationStopped.Register(quartz.Stop); }
附:IIS 網(wǎng)站低頻訪問導(dǎo)致工作進(jìn)程進(jìn)入閑置狀態(tài)的 解決辦法
IIS為網(wǎng)站默認(rèn)設(shè)定了20min閑置超時時間:20分鐘內(nèi)沒有處理請求、也沒有收到新的請求,工作進(jìn)程就進(jìn)入閑置狀態(tài)。
IIS上低頻web訪問會造成工作進(jìn)程關(guān)閉,此時應(yīng)用程序池回收,Timer等線程資源會被銷毀;當(dāng)工作進(jìn)程重新運作,Timer可能會重新生成起效, 但我們的設(shè)定的定時Job可能沒有按需正確執(zhí)行。
故為在IIS網(wǎng)站實現(xiàn)低頻web訪問下的定時任務(wù):
設(shè)置了Idle TimeOut =0;同時將【應(yīng)用程序池】->【正在回收】->不勾選【回收條件】
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