delayed_job在本地锁定

Question

我最近安装了delayed_job_active_record并完成了heroku的典型安装步骤，出于某种原因，当我在本地运行时（我和我的团队中的另一个开发人员）不断收到错误，我们的Web进程在尝试更新locked_at时会锁定。

15:22:35 web.1    | started with pid 672
15:22:35 worker.1 | started with pid 673
...
15:23:23 web.1    |   Delayed::Backend::ActiveRecord::Job Load (1.0ms)  UPDATE "delayed_jobs" SET locked_at = '2013-05-28 22:22:48.419281', locked_by = 'host:Jons-MacBook-Pro.local pid:673' WHERE id IN (SELECT id FROM "delayed_jobs" WHERE ((run_at <= '2013-05-28 22:22:48.418576' AND (locked_at IS NULL OR locked_at < '2013-05-28 18:22:48.418615') OR locked_by = 'host:Jons-MacBook-Pro.local pid:673') AND failed_at IS NULL) ORDER BY priority ASC, run_at ASC LIMIT 1 FOR UPDATE) RETURNING *

引用的PID是工作者PID，但是我有一个新的db（做db：drop db：create db：migrate to test）并且没有延迟的作业，所以没有理由让delayed_job被锁定任何东西。

那么..有没有人建议我应该在哪里开始调试这样的东西？我似乎无法找到它的来源，并希望在找出去哪里时能有所帮助。