Hangfire 嵌套批处理出错答案

【问题标题】：Error with Hangfire Nested BatchesHangfire 嵌套批处理出错
【发布时间】：2017-06-17 15:50:33
【问题描述】：

我们已经在我们的几个系统上成功使用 Hangfire 有一段时间了，并且已经成功使用 Hangfire 批处理功能来并行执行任务，但是我们在尝试在顺序作业中使用它时遇到了一些问题.

使用如下简单的批处理可以正常工作：

    BatchJob.Attach(masterBatch, batch =>
    {
        var lockJobId = batch.Enqueue<IProcessJob>(job => job.ObtainLock(businessUnit));

        var preparationJobId = batch.ContinueWith<IPrepareProcessJob>(lockJobId,
            job => job.PrepareData(businessUnit, workingJobData, JobCancellationToken.Null));

        var statisticsJobId = batch.ContinueWith<IPrepareProcessJob>(preparationJobId,
            job => job.AddStatistics(businessUnit, workingJobData, JobCancellationToken.Null));

        var processFileId = batch.ContinueWith<IProcessJob>(statisticsJobId,
            job => job.ProcessFile(workingJobData, notifierInstructions, businessUnit,
                            JobCancellationToken.Null));

        batch.ContinueWith<IProcessJob>(processFileId, job => job.ReleaseLock(businessUnit));
    });

但是，无论三个处理作业发生什么，我们都希望始终运行最终解锁作业，因此我们尝试在中间三个作业周围引入嵌套批处理，如下所示：

    BatchJob.Attach(masterBatch, batch =>
    {
        var lockJobId = batch.Enqueue<IProcessJob>(job => job.ObtainLock(businessUnit));

        var mainBatchId = batch.AwaitJob(lockJobId, mainBatch =>
        {
            var preparationJobId = mainBatch.Enqueue<IPrepareProcessJob>(
                job => job.PrepareData(businessUnit, jobData, JobCancellationToken.Null));

            var statisticsJobId = mainBatch.ContinueWith<IPrepareProcessJob>(preparationJobId,
                job => job.AddStatistics(businessUnit, jobData, JobCancellationToken.Null));

            mainBatch.ContinueWith<IProcessJob>(statisticsJobId,
                job => job.ProcessFile(jobData, notifierInstructions, businessUnit,
                    JobCancellationToken.Null));
        });

        batch.AwaitBatch<IProcessJob>(mainBatchId, job => job.ReleaseLock(businessUnit));
    });

这会产生错误：

Can't create a continuation for batch 'a5955434-294e-4568-9b64-c167feeb95da' because it doesn't exist.

正在调查 Hangfire 尝试附加最终释放锁时产生的错误。有人对我们可能做错了什么有任何建议吗？

【问题讨论】：

标签： c# hangfire

【解决方案1】：

我们又花了几个小时试图解决这个问题，我们仍然无法让嵌套批次的版本在不抛出错误的情况下工作，但是通过一些重新排列，我们可以在不嵌套的情况下获得所需的功能：

BatchJob.Attach(mainBatchId, batch =>
{
    var lockJobId = batch.Enqueue<IProcessJob>(job => job.ObtainLock(businessUnit));

    var preparationJobId = batch.ContinueWith<IPrepareProcessJob>(lockJobId,
        job => job.PrepareData(businessUnit, workingJobData, JobCancellationToken.Null));

    var statisticsJobId = batch.ContinueWith<IPrepareProcessJob>(preparationJobId,
        job => job.AddStatistics(businessUnit, workingJobData, JobCancellationToken.Null));

    batch.ContinueWith<IProcessJob>(statisticsJobId,
        job => job.ProcessFile(workingJobData, notifierInstructions, businessUnit,
            JobCancellationToken.Null));
});

// Catch-all unlock
BatchJob.AwaitBatch(mainBatchId,
    batch => batch.Enqueue<IProcessJob>(job => job.ReleaseLock(businessUnit)),
    $"Unlock for {reportName}", BatchContinuationOptions.OnAnyFinishedState);

【讨论】：