Question

当sshing进入网络服务器时，我可以整天重启delayed_job而没有任何问题。它会关闭现有的worker，启动一个新的worker并将tmp / pids / delayed_job.pid写入其进程ID。（我也在重新启动乘客以模仿我将要使用capistrano做什么）

app@StagingServer:/app/current$ touch tmp/restart.txt; RAILS_ENV=staging script/delayed_job restart
delayed_job: trying to stop process with pid 22170...
delayed_job: process with pid 22170 successfully stopped.
delayed_job: process with pid 22284 started.
app@StagingServer:/app/current$ touch tmp/restart.txt; RAILS_ENV=staging script/delayed_job restart
delayed_job: trying to stop process with pid 22284...
delayed_job: process with pid 22284 successfully stopped.
delayed_job: process with pid 22355 started.
app@StagingServer:/app/current$ touch tmp/restart.txt; RAILS_ENV=staging script/delayed_job restart
delayed_job: trying to stop process with pid 22355...
delayed_job: process with pid 22355 successfully stopped.
delayed_job: process with pid 22427 started.
app@StagingServer:/app/current$

但是，当我使用capistrano进行部署时

dev@ubuntu:~/app-site$ cap passenger:restart
    triggering start callbacks for `passenger:restart'
  * executing `multistage:ensure'
*** Defaulting to `staging'
  * executing `staging'
  * executing `passenger:restart'
  * executing "touch /app/current/tmp/restart.txt"
    servers: ["staging.app.com"]
    [staging.app.com] executing command
    command finished in 242ms
  * executing "cd /app/current;RAILS_ENV=staging script/delayed_job restart"
    servers: ["staging.app.com"]
    [staging.app.com] executing command
 ** [out :: staging.app.com] delayed_job: trying to stop process with pid 21646...
 ** [out :: staging.app.com] delayed_job: process with pid 21646 successfully stopped.
    command finished in 11889ms

好像很好吗？虽然不打印delayed_job的最后一行（我认为由于它没有以换行结尾），但这确实成功地创建了一个新进程。但是，它不会创建.pid文件，因此当我尝试重新启动时：

dev@ubuntu:~/app-site$ cap passenger:restart
    triggering start callbacks for `passenger:restart'
  * executing `multistage:ensure'
*** Defaulting to `staging'
  * executing `staging'
  * executing `passenger:restart'
  * executing "touch /app/current/tmp/restart.txt"
    servers: ["staging.app.com"]
    [staging.app.com] executing command
    command finished in 398ms
  * executing "cd /app/current;RAILS_ENV=staging script/delayed_job restart"
    servers: ["staging.app.com"]
    [staging.app.com] executing command
 ** [out :: staging.app.com] Warning: no instances running. Starting...
 ** [out :: staging.app.com] delayed_job: process with pid 21950 started.
    command finished in 6758ms

它不会停止现有流程。奇怪的是，这次它将创建一个新的进程和它的.pid文件。

这使得我运行了2个delayed_jobs进程，并且只有一个在.pid文件中。每增加2个上限，我会添加另一个delayed_job进程。之前的流程正在使用旧版本的应用程序，基本上是破解它。

配置/ deploy.rb：

namespace :passenger do
  desc "Restart Application"  
  task :restart do  
    run "touch #{current_path}/tmp/restart.txt"
    run "cd #{current_path};RAILS_ENV=#{deploy_env} script/delayed_job restart"
  end
end
after :deploy, "passenger:restart"

Ubuntu，nginx，乘客
守护进程（1.1.4）
delayed_job（2.1.4）
rails（3.0.9）

本地

capistrano（2.9.0）
capistrano-ext（1.2.1）

更新

阅读，似乎可能与守护进程内的竞争条件有关。但是我有点困惑为什么它在使用capistrano时只显示（并且始终如一）。我会尝试将命令改为停止，然后再开始睡眠。

Answer 1

通过使用停止和启动而不是重新启动来解决。由于竞争条件可能由守护进程宝石造成。

我仍然想知道其他人是否有更好的解决方案。

Answer 2

我遇到了这个问题，停止并开始没有为我工作，所以我想出了以下内容：

namespace :delayed_job do
desc 'Restart delayed_job worker'
  task :restart do
    on roles(:delayed_job) do
      within release_path do
        with rails_env: fetch(:rails_env) do
          execute :pkill , "-f", "'delayed_job'"
          execute :bundle, :exec, "bin/delayed_job", :start
        end
      end
    end
  end
end
...
after :restart,  "delayed_job:restart"

不是pkill的忠实粉丝，但这对我来说始终如一。希望这有帮助

Answer 3

在每次部署过程中，Capistrano都会为当前目录混排一个符号链接，这正为我孤立了PID。我们使用capistrano3-delayed-job宝石，建议将其中一个修复程序应用到deploy.rb：

set :linked_dirs, %w(tmp/pids)

# or

set :delayed_job_pid_dir, '/tmp'

其中第一个为我们解决了这个问题。它将当前/ tmp / pids移到shared / tmp /并在当前树中进行符号链接，以使其在部署中持久存在。

使用capistrano重新启动delayed_job时，并不总是创建pid文件

3 个答案: