通过 Capistrano 任务启动具有/特定队列的多个延迟作业工作者

Question

我正在研究使用带延迟作业的队列。我找到了this page，它概述了启动工人的各种方法，但是我想保留我目前的 Capistrano 方法：

set :delayed_job_args, "-n 2 -p ecv2.production"
after "deploy:start",  "delayed_job:start"
...

我想知道如何修改 delay_job_args 以处理生成 1 个具有特定队列的工作人员，以及为每个其他工作生成 1 个工作人员。到目前为止，我所拥有的只是像这样覆盖每个任务：

namespace :delayed_job do
  task :restart, :roles => :app do
    run "cd #{current_path}; RAILS_ENV=#{rails_env} script/delayed_job -p ecv2.production --queue=export restart"
    run "cd #{current_path}; RAILS_ENV=#{rails_env} script/delayed_job -p ecv2.production restart"
  end
end

...但这并不好玩。有什么建议吗？

Answer 1

我在deploy.rb 文件中使用此设置将我的作业分成两个队列，每个队列隔离一名工作人员：

namespace :delayed_job do
  task :start, roles: :app do
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i queue_one --queue=one start"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i queue_two --queue=two start"
  end

  task :stop, roles: :app do
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i queue_one --queue=one stop"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i queue_two --queue=two stop"
  end

  task :restart, roles: :app do
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i queue_one --queue=one restart"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i queue_two --queue=two restart"
  end
end

命令的-i name 部分非常重要。这就是允许多个delayed_job 实例运行的部分。

如果您想将工作人员添加到特定队列，那么您可以像这样扩展它们（我有两个工作人员专门在队列一上，一个工作人员专门在队列二上）：

namespace :delayed_job do
  task :start, roles: :app do
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i one1 --queue=one start"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i one2 --queue=one start"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i two --queue=two start"
  end

  task :stop, roles: :app do
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i one1 stop"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i one2 stop"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i two stop"
  end

  task :restart, roles: :app do
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i one1 --queue=one restart"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i one2 --queue=one restart"
    run "cd #{current_path}; #{rails_env} bundle exec script/delayed_job -i two --queue=two restart"
  end
end

Answer 2

经过一番折腾，我发现的技巧是恢复到“set :delayed_job_args”并使用--queues=（复数）而不是--queue=（单数）。希望这可以帮助遇到同样问题的其他人。

set :delayed_job_args, "-n 2 -p ecv2.production --queues=cache,export"

更新：我现在使用的...

after "deploy:stop",    "delayed_job:stop"
after "deploy:start",   "delayed_job:start"
after "deploy:restart", "delayed_job:restart"

namespace :delayed_job do
  # See 'man nice' for details, default priority is 10 and 15 is a bit lower
  task :start, :roles => :app do
    run "cd #{current_path}; #{rails_env} nice -n 15 ruby script/delayed_job -n 1 -p yourapp.#{application} start"
  end

  task :restart, :roles => :app do
    stop
    start
  end
end