asp.net-core – 如何在ASP.NET Core中启动Quartz？

假设工具：Visual Studio 2017 RTM,.NET Core 1.1,.NET Core SDK 1.0,SQL Server Express 2016 LocalDB.

在Web应用程序.csproj中：

<Project Sdk="Microsoft.NET.Sdk.Web">

  <!-- .... existing contents .... -->

  <!-- add the following ItemGroup element,it adds required packages -->
  <ItemGroup>
    <PackageReference Include="Quartz" Version="3.0.0-alpha2" />
    <PackageReference Include="Quartz.Serialization.Json" Version="3.0.0-alpha2" />
  </ItemGroup>

</Project>

在Program类中(默认情况下由Visual Studio搭建)：

public class Program
{
    private static IScheduler _scheduler; // add this field

    public static void Main(string[] args)
    {
        var host = new WebHostBuilder()
            .UseKestrel()
            .UseContentRoot(Directory.GetCurrentDirectory())
            .UseIISIntegration()
            .UseStartup<Startup>()
            .UseApplicationInsights()
            .Build();

        StartScheduler(); // add this line

        host.Run();
    }

    // add this method
    private static void StartScheduler()
    {
        var properties = new NameValueCollection {
            // json serialization is the one supported under .NET Core (binary isn't)
            ["quartz.serializer.type"] = "json",// the following setup of job store is just for example and it didn't change from v2
            // according to your usage scenario though,you definitely need 
            // the ADO.NET job store and not the RAMJobStore.
            ["quartz.jobStore.type"] = "Quartz.Impl.AdoJobStore.JobStoreTX,Quartz",["quartz.jobStore.useProperties"] = "false",["quartz.jobStore.dataSource"] = "default",["quartz.jobStore.tablePrefix"] = "QRTZ_",["quartz.jobStore.driverDelegateType"] = "Quartz.Impl.AdoJobStore.SqlServerDelegate,["quartz.dataSource.default.provider"] = "SqlServer-41",// SqlServer-41 is the new provider for .NET Core
            ["quartz.dataSource.default.connectionString"] = @"Server=(localdb)MSSQLLocalDB;Database=Quartz;Integrated Security=true"
        };

        var schedulerFactory = new StdSchedulerFactory(properties);
        _scheduler = schedulerFactory.GetScheduler().Result;
        _scheduler.Start().Wait();

        var userEmailsJob = JobBuilder.Create<SendUserEmailsJob>()
            .WithIdentity("SendUserEmails")
            .Build();
        var userEmailsTrigger = TriggerBuilder.Create()
            .WithIdentity("UserEmailsCron")
            .StartNow()
            .WithCronSchedule("0 0 17 ? * MON,TUE,WED")
            .Build();

        _scheduler.ScheduleJob(userEmailsJob,userEmailsTrigger).Wait();

        var adminEmailsJob = JobBuilder.Create<SendAdminEmailsJob>()
            .WithIdentity("SendAdminEmails")
            .Build();
        var adminEmailsTrigger = TriggerBuilder.Create()
            .WithIdentity("AdminEmailsCron")
            .StartNow()
            .WithCronSchedule("0 0 9 ? * THU,FRI")
            .Build();

        _scheduler.ScheduleJob(adminEmailsJob,adminEmailsTrigger).Wait();
    }
}

作业类的示例：

public class SendUserEmailsJob : IJob
{
    public Task Execute(IJobExecutionContext context)
    {
        // an instance of email service can be obtained in different ways,// e.g. service locator,constructor injection (requires custom job factory)
        IMyEmailService emailService = new MyEmailService();

        // delegate the actual work to email service
        return emailService.SendUserEmails();
    }
}

完整答案

Quartz for .NET Core

首先,根据this announcement,你必须使用Quartz的v3,因为它的目标是.NET Core.

目前,只有v3软件包的alpha版本是available on NuGet.看起来团队花了很多精力发布2.5.0,而不是针对.NET Core.尽管如此,在他们的GitHub回购中,主分支已经专注于v3,基本上,open issues for v3 release似乎并不重要,主要是旧的愿望清单项目,恕我直言.由于最近commit activity相当低,我预计v3会在几个月内发布,或者可能是半年 – 但没有人知道.

乔布斯和IIS回收

如果Web应用程序将在IIS下托管,则必须考虑工作进程的回收/卸载行为. ASP.NET Core Web应用程序作为常规.NET Core进程运行,与w3wp.exe分开 – IIS仅用作反向代理.然而,当循环或卸载w3wp.exe的实例时,相关的.NET Core应用程序进程也会发出信号以退出(根据this).

Web应用程序也可以在非IIS反向代理(例如NGINX)后面自行托管,但我会假设您使用IIS,并相应地缩小我的答案.

回收/卸载引入的问题在post referenced by @darin-dimitrov中得到了很好的解释：

>例如,如果在星期五9:00,该进程已关闭,因为几个小时之前它由于不活动而被IIS卸载 – 在该进程再次启动之前不会发送管理员电子邮件.为避免这种情况,请配置IIS以最小化卸载/重新循环(see this answer).

>根据我的经验,上述配置仍然没有100％保证IIS永远不会卸载应用程序.为了100％保证您的进程已启动,您可以设置一个命令,定期向您的应用程序发送请求,从而使其保持活动状态.

>回收/卸载主机进程时,必须正常停止作业,以避免数据损坏.

为什么要在Web应用程序中托管预定作业

尽管存在上面列出的问题,我仍然可以想到将这些电子邮件作业托管在Web应用程序中的一个理由.决定只有一种应用程序模型(ASP.NET).这种方法简化了学习曲线,部署程序,生产监控等.

如果您不想引入后端微服务(这是将电子邮件作业移动到的好地方),那么有必要克服IIS回收/卸载行为,并在Web应用程序中运行Quartz.

或许你有其他原因.

持久的工作商店

在您的方案中,作业执行的状态必须保持在进程外.因此,默认RAMJobStore不适合,您必须使用ADO.NET作业存储.

由于您在问题中提到了SQL Server,我将提供SQL Server数据库的示例设置.

如何启动(并正常停止)调度程序

我假设您使用Visual Studio 2017和最新/最新版本的.NET Core工具.我的是.NET Core Runtime 1.1和.NET Core SDK 1.0.

对于数据库设置示例,我将在SQL Server 2016 Express LocalDB中使用名为Quartz的数据库.数据库设置脚本可以是found here.

首先,向Web应用程序.csproj添加必需的包引用(或者在Visual Studio中使用NuGet包管理器GUI执行此操作)：

<Project Sdk="Microsoft.NET.Sdk.Web">

  <!-- .... existing contents .... -->

  <!-- the following ItemGroup adds required packages -->
  <ItemGroup>
    <PackageReference Include="Quartz" Version="3.0.0-alpha2" />
    <PackageReference Include="Quartz.Serialization.Json" Version="3.0.0-alpha2" />
  </ItemGroup>

</Project>

在Migration Guide和V3 Tutorial的帮助下,我们可以弄清楚如何启动和停止调度程序.我更喜欢将它封装在一个单独的类中,让我们将它命名为QuartzStartup.

using System;
using System.Collections.Specialized;
using System.Threading.Tasks;
using Quartz;
using Quartz.Impl;

namespace WebApplication1
{
    // Responsible for starting and gracefully stopping the scheduler.
    public class QuartzStartup
    {
        private IScheduler _scheduler; // after Start,and until shutdown completes,references the scheduler object

        // starts the scheduler,defines the jobs and the triggers
        public void Start()
        {
            if (_scheduler != null)
            {
                throw new InvalidOperationException("Already started.");
            }

            var properties = new NameValueCollection {
                // json serialization is the one supported under .NET Core (binary isn't)
                ["quartz.serializer.type"] = "json",// the following setup of job store is just for example and it didn't change from v2
                ["quartz.jobStore.type"] = "Quartz.Impl.AdoJobStore.JobStoreTX,// SqlServer-41 is the new provider for .NET Core
                ["quartz.dataSource.default.connectionString"] = @"Server=(localdb)MSSQLLocalDB;Database=Quartz;Integrated Security=true"
            };

            var schedulerFactory = new StdSchedulerFactory(properties);
            _scheduler = schedulerFactory.GetScheduler().Result;
            _scheduler.Start().Wait();

            var userEmailsJob = JobBuilder.Create<SendUserEmailsJob>()
                .WithIdentity("SendUserEmails")
                .Build();
            var userEmailsTrigger = TriggerBuilder.Create()
                .WithIdentity("UserEmailsCron")
                .StartNow()
                .WithCronSchedule("0 0 17 ? * MON,WED")
                .Build();

            _scheduler.ScheduleJob(userEmailsJob,userEmailsTrigger).Wait();

            var adminEmailsJob = JobBuilder.Create<SendAdminEmailsJob>()
                .WithIdentity("SendAdminEmails")
                .Build();
            var adminEmailsTrigger = TriggerBuilder.Create()
                .WithIdentity("AdminEmailsCron")
                .StartNow()
                .WithCronSchedule("0 0 9 ? * THU,FRI")
                .Build();

            _scheduler.ScheduleJob(adminEmailsJob,adminEmailsTrigger).Wait();
        }

        // initiates shutdown of the scheduler,and waits until jobs exit gracefully (within allotted timeout)
        public void Stop()
        {
            if (_scheduler == null)
            {
                return;
            }

            // give running jobs 30 sec (for example) to stop gracefully
            if (_scheduler.Shutdown(waitForJobsToComplete: true).Wait(30000)) 
            {
                _scheduler = null;
            }
            else
            {
                // jobs didn't exit in timely fashion - log a warning...
            }
        }
    }
}

注意1.在上面的示例中,SendUserEmailsJob和SendAdminEmailsJob是实现IJob的类. IJob接口与IMyEmailService略有不同,因为它返回void Task而不是Task< bool>.两个作业类都应该将IMyEmailService作为依赖项(可能是构造函数注入).

注意2.对于能够及时退出的长时间运行的作业,在IJob.Execute方法中,它应该观察IJobExecutionContext.CancellationToken的状态.这可能需要在IMyEmailService接口中进行更改,以使其方法接收CancellationToken参数：

public interface IMyEmailService
{
    Task<bool> SendAdminEmails(CancellationToken cancellation);
    Task<bool> SendUserEmails(CancellationToken cancellation);
}

何时何地启动和停止调度程序

在ASP.NET Core中,应用程序引导代码驻留在类Program中,就像在控制台应用程序中一样.调用Main方法来创建Web主机,运行它,并等待它退出：

public class Program
{
    public static void Main(string[] args)
    {
        var host = new WebHostBuilder()
            .UseKestrel()
            .UseContentRoot(Directory.GetCurrentDirectory())
            .UseIISIntegration()
            .UseStartup<Startup>()
            .UseApplicationInsights()
            .Build();

        host.Run();
    }
}

最简单的方法就是在Main方法中调用QuartzStartup.Start,就像我在TL中做的那样; DR.但由于我们必须正确处理进程关闭,我更喜欢以更一致的方式挂接启动和关闭代码.

这一行：

.UseStartup<Startup>()

指的是一个名为Startup的类,它在Visual Studio中创建新的ASP.NET Core Web Application项目时被搭建. Startup类如下所示：

public class Startup
{
    public Startup(IHostingEnvironment env)
    {
        // scaffolded code...
    }

    public IConfigurationRoot Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        // scaffolded code...
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app,IHostingEnvironment env,ILoggerFactory loggerFactory)
    {
        // scaffolded code...
    }
}

很明显,应该在Startup类的一个方法中插入对QuartzStartup.Start的调用.问题是,应该挂起QuartzStartup.Stop.

在旧版.NET Framework中,ASP.NET提供了IRegisteredObject接口.根据this post和documentation,在ASP.NET Core中它被IApplicationLifetime取代.答对了.可以通过参数将IApplicationLifetime的实例注入到Startup.Configure方法中.

为了保持一致性,我将QuartzStartup.Start和QuartzStartup.Stop挂钩到IApplicationLifetime：

public class Startup
{
    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(
        IApplicationBuilder app,ILoggerFactory loggerFactory,IApplicationLifetime lifetime) // added this parameter
    {
        // the following 3 lines hook QuartzStartup into web host lifecycle
        var quartz = new QuartzStartup();
        lifetime.ApplicationStarted.Register(quartz.Start);
        lifetime.ApplicationStopping.Register(quartz.Stop);

        // .... original scaffolded code here ....
    }

    // ....the rest of the scaffolded members ....
}

请注意,我已使用额外的IApplicationLifetime参数扩展了Configure方法的签名.根据documentation,ApplicationStopping将阻止,直到注册的回调完成.

在IIS Express和ASP.NET Core模块上正常关闭

我能够在IIS上观察IApplicationLifetime.ApplicationStopping挂钩的预期行为,并安装了最新的ASP.NET Core模块. IIS Express(与Visual Studio 2017社区RTM一起安装)和具有过时版本的ASP.NET Core模块的IIS都没有始终如一地调用IApplicationLifetime.ApplicationStopping.我相信这是因为this bug修复了.

您可以安装最新版本的ASP.NET Core模块from here.请按照“安装最新的ASP.NET核心模块”部分中的说明进行操作.

Quartz vs. FluentScheduler

我还看了一下FluentScheduler,因为它被@Brice Molesti提议作为替代库.我的第一印象是,与Quartz相比,FluentScheduler是一个相当简单且不成熟的解决方案.例如,FluentScheduler不提供作业状态持久性和集群执行等基本功能.