我的工作执行了任意次数，即使只安排了一次

Question

Hangfire 1.6.17
SQL 服务器 2016 (13.0.4206.0)

我有一个使用 OWIN 托管 Hangfire 服务器的 C# 控制台应用程序，如下所示：

public class Startup
{
    public void Configuration(IAppBuilder aAppBuilder)
    {
        //How we want to use Hangfire
        GlobalConfiguration.Configuration
                           .UseSqlServerStorage("HangfireConnectionString")
                           .UseConsole(new ConsoleOptions
                                       {
                                           BackgroundColor = "#0d3163",
                                           TextColor = "#ffffff",
                                           TimestampColor = "#00aad7"
                                       });

        //Read the settings file
        SettingsIni iniSettings = new SettingsIni(GeneralHelper.GetAppPath() + "settings.ini");

        //Dashboard
        aAppBuilder.UseHangfireDashboard(iniSettings.HttpServer.Path, new DashboardOptions
                                                                      {
                                                                          AppPath = "/",
                                                                          Authorization = new[]
                                                                                          {
                                                                                              new HangfireAuthorizationFilter()
                                                                                          }
                                                                      });

        //Server
        BackgroundJobServerOptions serverOptions = new BackgroundJobServerOptions
                                                   {
                                                       Queues = GeneralHelper.GetQueueNames(iniSettings).ToArray()
                                                   };

        aAppBuilder.UseHangfireServer(serverOptions);

        //Ensure our recurring tasks are running if required.
        if (iniSettings.Behaviour.DoPlatformManagerInit) TpHangfireJobsManager.Initialise();
    }
}

作为应用程序启动的一部分，我添加了一个 fire and forget 作业，如下所示：

BackgroundJob.Enqueue<TpHardLinkAttachmentsForEmailMessagesWatchDog>(aX => aX.ExecuteJob(null, new TpHardLinkAttachmentsForEmailMessagesWatchDogParamsInput
                                                {
                                                    ForYear = 2017
                                                }));

正在执行的方法是：

public override void ExecuteJob(PerformContext aContext, TpHardLinkAttachmentsForEmailMessagesWatchDogParamsInput aParams)
{
    Trace.WriteLine($"Params: {aParams.ForYear}");
    DateTime startDate = new DateTime(aParams.ForYear, 1, 1);
    DateTime endDate = new DateTime(aParams.ForYear, 1, 31);

    //Start with a huge record id so we can work backwards
    long currRecId = int.MaxValue;

    //Keep getting records until we are done
    while (true)
    {


        //Find all records that have to be processed. We start with the highest record id in the year and then work backwards until we run out of record
        long idLast = currRecId;
        Trace.WriteLine($"Id Last: {idLast}");
        List<EmailActivityTableModel> recordsToProcess = _EmailActivityDomainService.GetWhere(
                                                                                        aR => aR.Id < idLast &&
                                                                                              aR.Created >= startDate &&
                                                                                              aR.Created <= endDate &&
                                                                                              (
                                                                                                  aR.ExternalIdKind == ExternalIdKindEnum.Family ||
                                                                                                  aR.ExternalIdKind == ExternalIdKindEnum.Individual
                                                                                              ) &&
                                                                                              (
                                                                                                  aR.ExternalId != "" ||
                                                                                                  aR.ExternalId != "-1"
                                                                                              ) //Ensure we have an external identifier
                                                                                    ).OrderByDescending(aR => aR.Id)
                                                                                    .Take(5).ToList();

        //We are done if we did not find any records
        if (recordsToProcess.Count == 0)
            break;

        aContext.WriteLine("Process {0} records.", recordsToProcess.Count);
        Trace.WriteLine($"Record Count: {recordsToProcess.Count}");

        foreach (EmailActivityTableModel emailActivityRecord in recordsToProcess)
        {
            aContext.WriteLine(emailActivityRecord.Id);

            currRecId = emailActivityRecord.Id;
            Trace.WriteLine($"Curr Rec Id: {emailActivityRecord.Id}");
        }

        //TESTING - Bail after the first iteration so 5 records
        return;
    }
}

该方法所做的就是最终从数据库中读取一些记录并输出主键。我看到的是该方法被多次调用（数量因控制台应用程序的每个运行而异）并且我看到以下内容：

不过我在 HangFire 中只看到一个成功的任务：

我没有异常（注意每次都完成所有 5 次迭代）因此作业不会因此而重新启动。

所以我的问题是为什么我的 ExecuteJob() 被调用了这么多次？

Answer 1

为了完整起见，我正在回答这个问题。

原来我收到了一个异常位，它没有显示在我的日志中。我最终通过添加 coloured console logger.

找到了它

我正在使用名为 HangFire.Console which has an issue with the attribute DisableConcurrentExecution as detailed here 的第三方软件包。将该属性交换为 Mutex，现在一切正常。

我的工作执行了任意次数，即使只安排了一次

My job executes an arbitrary number of times even though only scheduled once

c#

jobs

job-scheduling

hangfire