如何在实际作业中引用活动的delayed_job

Question

我正在研究一种解决方案,以显示延迟作业的完成百分比(使用delayed_job gem).目前,我的delayed_jobs表的数据库迁移类似于以下内容:

class CreateDelayedJobs < ActiveRecord::Migration
  def self.up
    create_table :delayed_jobs, :force => true do |table|
      table.integer  :priority, :default => 0      # Allows some jobs to jump to the front of the queue
      table.integer  :attempts, :default => 0      # Provides for retries, but still fail eventually.
      table.text     :handler                      # YAML-encoded string of the object that will do work
      table.text     :last_error                   # reason for last failure (See Note below)
      table.datetime :run_at                       # When to run. Could be Time.zone.now for immediately, or sometime in the future.
      table.datetime :locked_at                    # Set when a client is working on this object
      table.datetime :failed_at                    # Set when all retries have failed (actually, by default, the record is deleted instead)
      table.string   :locked_by                    # Who is working on this object (if locked)
      table.string   :queue                        # The name of the queue this job is in
      table.integer  :progress
      table.timestamps

    end

    add_index :delayed_jobs, [:priority, :run_at], :name => 'delayed_jobs_priority'
  end

  def self.down
    drop_table :delayed_jobs
  end
end

我在一个控制器方法中使用一个enqueue进程来处理延迟的作业,并在lib/build_detail.rb中引用一个类:

Delayed::Job.enqueue(BuildDetail.new(@object, @com))

lib/build_detail.rb文件如下:

class BuildDetail < Struct.new(:object, :com)

  def perform
    total_count = object.person_ids.length
    progress_count = 0

    people = com.person object.person_ids do |abc|
      progress_count += abc.size
      Delayed::Job.current.update_attribute :progress, (progress_count/total_count)
    end
  end  

end

延迟:: Job.current不起作用.我在这篇文章中看到了提出的Delayed :: Job.current方法,但是看起来这个方法从未包含在主要的delayed_jobs github项目中.

如何在每次作业完成循环时访问当前作业(从实际作业中),更新进度字段？

Answer 1

现在回答很晚但是我遇到了同样的要求,所以可能会对某人有所帮助.您需要做的就是实现自定义作业和before-hook,您将在当前作业中存储引用:

class MyTestJob
  def before(job)
    @job = job
  end

  def perform
    ...
    @job.update_attributes({ progress: your_progress_var }, without_protection: true)
  end
end

Answer 2

延迟工作的一件很酷的事情也是这里阻碍你的事情。当您对大量延迟作业进行排队时，如果您有多个运行工作程序的实例，则可以并行处理它们 - 例如，您可以有 10 台机器，每台机器运行您的应用程序实例访问同一数据库，并获得 10 倍的处理速度提升。因此，可能有多个“当前”工作。一次只运行一项作业是一种特殊情况。

这是查看所有活动作业状态的方法。如果您只运行一个实例，它只会返回一项作业，因此这将满足您的情况：

active_jobs = Delayed::Job.where("progress > 0")
progress_of_first_job = active_jobs.first.progress if active_jobs.present?
progress_of_all_jobs = active_jobs.map{|job| job.progress}

Progress_of_first_job 是其中一个作业的进度（为了安全起见，请使用 order 子句）。Progress_of_all_jobs 是每个活动作业的进度值数组（可能为空）。