ASP.NET Core 2.2+Quartz.Net 實現Web定時任務

作者：Julian_醬

連結：http://www.cnblogs.com/mi12205599/p/10361763.html

 

作為一枚後端程式狗，專案實踐常遇到定時任務的工作，最容易想到的的思路就是利用Windows計劃任務/wndows service程式/Crontab程式等主機方法在主機上部署定時任務程式/指令碼。

但是很多時候，若使用的是共享主機或者受控主機，這些主機不允許你私自安裝exe程式、Windows服務程式。

碼甲會想到在web程式中做定時任務， 目前有兩個方向：

1、AspNetCore自帶的HostService， 這是一個輕量級的後臺服務， 需要搭配timer完成定時任務

2、老牌Quartz.Net元件，支援複雜靈活的Scheduling、支援ADO/RAM Job任務儲存、支援叢集、支援監聽、支援外掛。

 

此處我們的專案使用稍複雜的Quartz.net實現Web定時任務。

專案背景

最近需要做一個計數程式：採用redis計數，設定每小時將當日累積資料持久化到關係型資料庫sqlite。

新增Quartz.Net Nuget 依賴包：

 

1、定義定時任務內容： Job

2、設定觸發條件： Trigger

3、將Quartz.Net整合進AspNet Core

頭腦風暴

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任務的過程，這個行為是利用反射機制呼叫無參建構式構造出的Job實體。

 

下麵是原始碼：

//----------------選自Quartz.Simpl.SimpleJobFactory類-----------
using System;
using Quartz.Logging;
using Quartz.Spi;
using Quartz.Util;
namespace Quartz.Simpl
{
    ///  
    /// The default JobFactory used by Quartz - simply calls 
    ///  on the job class.
    /// 

///
///
/// James House
/// Marko Lahma (.NET)
public class SimpleJobFactory : IJobFactory
{
private static readonly ILog log = LogProvider.GetLogger(typeof (SimpleJobFactory));
///
/// Called by the scheduler at the time of the trigger firing, in order to
/// produce a instance on which to call Execute.
///
///
/// 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
/// state, which will require human
/// intervention (e.g. an application restart after fixing whatever
/// configuration problem led to the issue with instantiating the Job).
///
/// The TriggerFiredBundle from which the
///   and other info relating to the trigger firing can be obtained.
///
/// the newly instantiated Job
///

 

 SchedulerException if there is a problem instantiating the Job.
public virtual IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
IJobDetail jobDetail = bundle.JobDetail;
Type jobType = jobDetail.JobType;
try
{
if (log.IsDebugEnabled())
{
log.Debug($”Producing instance of Job ‘{jobDetail.Key}‘, class={jobType.FullName}“);
}
return ObjectUtils.InstantiateType(jobType);
}
catch (Exception e)
{
SchedulerException se = new SchedulerException($”Problem instantiating class ‘{jobDetail.JobType.FullName}‘”, e);
throw se;
}
}

///
/// Allows the job factory to destroy/cleanup the job if needed.
/// No-op when using SimpleJobFactory.
///
public virtual void ReturnJob(IJob job)
{
var disposable = job as IDisposable;
disposable?.Dispose();
}
}
}

//------------------節選自Quartz.Util.ObjectUtils類------------
public static T InstantiateType(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任務依賴了其他元件（Job實體化時多參），此時預設的SimpleJobFactory不能滿足實體化要求， 需要考慮將Job任務作為依賴註入元件，加入依賴註入容器。

關鍵思路：

① IScheduler 開放了JobFactory 屬性，便於你控制Job任務的實體化方式；

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

 

②AspNet Core的服務架構是以依賴註入為基礎的，利用ASPNET Core已有的依賴註入容器IServiceProvider管理Job任務的建立過程。

編碼實踐

1、定義Job內容

// -------每小時將redis資料持久化到sqlite， 每日凌晨跳針，持久化昨天全天資料-
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();
        }
        public async Task Execute(IJobExecutionContext context)
        {
            // 觸發時間在凌晨，則同步昨天的計數
            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、註冊Job和Trigger

namespace EqidManager
{
    using IOCContainer = IServiceProvider;
    // Quartz.Net啟動後註冊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();
            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()
               .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");
        }
    }
    /// 
    /// IOCJobFactory ：實現在Timer觸發的時候註入生成對應的Job元件
    /// 

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、結合ASpNet Core 註入元件；系結Quartz.Net

//-------------------------------擷取自Startup檔案---------------
......
services.AddTransient();     
// 這裡使用瞬時依賴註入
services.AddSingleton();
......
// 系結Quartz.Net
public void Configure(IApplicationBuilder app, Microsoft.AspNetCore.Hosting.IApplicationLifetime lifetime, ILoggerFactory loggerFactory)
{
     var quartz = app.ApplicationServices.GetRequiredService();
     lifetime.ApplicationStarted.Register(quartz.Start);
     lifetime.ApplicationStopped.Register(quartz.Stop);
}

 

附：IIS 網站低頻訪問導致工作行程進入閑置狀態的 解決辦法

IIS為網站預設設定了20min閑置超時時間：20分鐘內沒有處理請求、也沒有收到新的請求，工作行程就進入閑置狀態。

 

IIS上低頻web訪問會造成工作行程關閉，此時應用程式池回收，Timer等執行緒資源會被銷毀；當工作行程重新運作，Timer可能會重新生成起效， 但我們的設定的定時Job可能沒有按需正確執行。

故為在IIS網站實現低頻web訪問下的定時任務：

 

設定Idle TimeOut =0；同時將【應用程式池】->【正在回收】->不勾選【回收條件】