dashboards.rb

ActiveAdmin::Dashboards.build do
  # Add this section in your dashboard...

  section "Background Jobs" do
    now = Time.now.getgm
    ul do
      li do
        jobs = Delayed::Job.where('failed_at is not null').count(:id)
        link_to "#{jobs} failing jobs", admin_jobs_path(q: {failed_at_is_not_null: true}), style: 'color: red'
      end
      li do
        jobs = Delayed::Job.where('run_at <= ?', now).count(:id)
        link_to "#{jobs} late jobs", admin_jobs_path(q: {run_at_lte: now.to_s(:db)}), style: 'color: hsl(40, 100%, 40%)'
      end
      li do
        jobs = Delayed::Job.where('run_at >= ?', now).count(:id)
        link_to "#{jobs} scheduled jobs", admin_jobs_path(q: {run_at_gte: now.to_s(:db)}), style: 'color: green'
      end
    end
  end

  # ...
end

jobs.rb

ActiveAdmin.register Delayed::Job, as: 'Job' do
  menu parent: 'Admin'

  actions :index, :show, :edit, :update, :destroy

  index do
    column :id
    column :queue
    column :priority
    column :attempts
    column :failed_at
    column :run_at
    column :created_at
    column :locked_by
    column :locked_at
    default_actions
  end

  form do |f|
    f.inputs "Scheduling" do
      f.input :priority
      f.input :queue
      f.input :run_at
    end

    f.inputs "Details" do
      f.input :id, input_html:          {disabled: true}
      f.input :created_at, input_html:  {disabled: true}
      f.input :updated_at, input_html:  {disabled: true}
      f.input :handler, input_html:     {disabled: true}
    end

    f.inputs "Diagnostics" do
      f.input :attempts,    input_html: {disabled: true}
      f.input :failed_at,   input_html: {disabled: true}
      f.input :last_error,  input_html: {disabled: true}
      f.input :locked_at,   input_html: {disabled: true}
      f.input :locked_by,   input_html: {disabled: true}
    end
    f.buttons
  end

  action_item :only => [:edit] do
    link_to 'Delete Job', admin_job_path(resource),
            'data-method' => :delete, 'data-confirm' => 'Are you sure?'
  end

  action_item :only => [:show, :edit] do
    link_to 'Schedule now', run_now_admin_job_path(resource), 'data-method' => :post,
      :title => 'Cause a job scheduled in the future to run now.'
  end

  action_item :only => [:show, :edit] do
    link_to 'Reset Job', reset_admin_job_path(resource), 'data-method' => :post,
      :title => 'Resets the state caused by errors. Lets a worker give it another go ASAP.'
  end

  member_action :run_now, :method => :post do
    resource.update_attributes run_at: Time.now
    redirect_to action: :index
  end

  member_action :reset, :method => :post do
    resource.update_attributes locked_at: nil, locked_by: nil, attempts: 0, last_error: nil
    resource.update_attribute :attempts, 0
    redirect_to action: :index
  end

end