ruby-on-rails – puma start导致“已经有服务器绑定：”错误

我总是在部署过程结束时停止并启动美洲狮.我运行pumactl -F< config_path>停止,工作,然后命令puma -q -d -e staging -C< config_path>,有时(并非总是)导致以下错误：

[12802] Puma starting in cluster mode... 
[12802] * Version 2.11.3 (ruby 2.1.2-p95),codename: Intrepid Squirrel
[12802] * Min threads: 2,max threads: 4
[12802] * Environment: staging
[12802] * Process workers: 2
[12802] * Phased restart available 
[12802] * Listening on unix:///<app_dir>/tmp/puma/sockets/puma.sock 
<ruby_path>/2.1.0/gems/puma-2.11.3/lib/puma/binder.rb:284:in `add_unix_listener': There is already a server bound to: <app_dir>/tmp/puma/sockets/puma.sock (RuntimeError)
<ruby_path>/2.1.0/gems/puma-2.11.3/lib/puma/binder.rb:124:in `block in parse'
<ruby_path>/2.1.0/gems/puma-2.11.3/lib/puma/binder.rb:82:in `each'
<ruby_path>/2.1.0/gems/puma-2.11.3/lib/puma/binder.rb:82:in `parse'
<ruby_path>/2.1.0/gems/puma-2.11.3/lib/puma/cluster.rb:325:in `run'
<ruby_path>/2.1.0/gems/puma-2.11.3/lib/puma/cli.rb:216:in `run'
<ruby_path>/2.1.0/gems/puma-2.11.3/bin/puma:10:in `<top (required)>'
<ruby_path>/2.1.0/bin/puma:23:in `load'
<ruby_path>/2.1.0/bin/puma:23:in `<main>'

如果我之后尝试再次运行相同的puma start命令,它会起作用.

这是我的puma配置：

#!/usr/bin/env puma

directory "<app_dir>/current"
rackup "<app_dir>/current/config.ru"
environment "staging"

pidfile "<app_dir>/tmp/puma/pid"
state_path "<app_dir>/tmp/puma/state"
activate_control_app "<app_dir>/tmp/puma/sockets/pumactl.sock"

stdout_redirect "<app_dir>/shared/log/puma.error.log","<app_dir>/shared/log/puma.access.log",true

threads 2,4

bind "unix:///<app_dir>/tmp/puma/sockets/puma.sock"

workers 2

我的问题：

>如何重现此错误？
>我该如何解决？这是puma还是我的配置问题？