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ASP.NET Core 2.2+Quartz.Net 實現Web定時任務

作者:Julian_醬

鏈接: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/腳本。

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組件,支持複雜靈活的Scheduling、支持ADO/RAM Job任務儲存、支持集群、支持監聽、支持插件。

 

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。

添加Quartz.Net Nuget 依賴包:

 

1、定義定時任務內容: Job

2、設置觸發條件: Trigger

3、將Quartz.Net集成進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任務依賴了其他組件(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任務作為依賴註入組件,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任務的創建過程。

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組件
    /// 

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 註入組件;系結Quartz.Net

//-------------------------------截取自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:

 

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

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