Address already in use - bind(2) (Errno::EADDRINUSE)

Question

I am trying to deploy Rails app with the Puma web server. When trying to start Puma server with a config file bundle exec puma -C config/puma.rb I get an error that the address is already in use.

Does someone know how to fix this?

bundle exec puma -C config/puma.rb
[23699] Puma starting in cluster mode...
[23699] * Version 2.11.3 (ruby 2.0.0-p353), codename: Intrepid Squirrel
[23699] * Min threads: 5, max threads: 5
[23699] * Environment: development
[23699] * Process workers: 2
[23699] * Preloading application
Jdbc-MySQL is only for use with JRuby
[23699] * Listening on tcp://0.0.0.0:3000
/.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/binder.rb:210:in `initialize': Address already in use - bind(2) (Errno::EADDRINUSE)
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/binder.rb:210:in `new'
    from /Users/lexi87/.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/binder.rb:210:in `add_tcp_listener'
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/binder.rb:96:in `block in parse'
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/binder.rb:82:in `each'
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/binder.rb:82:in `parse'
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/runner.rb:119:in `load_and_bind'
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/cluster.rb:302:in `run'
    from /.rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/lib/puma/cli.rb:216:in `run'
    from /rvm/gems/ruby-2.0.0-p353/gems/puma-2.11.3/bin/puma:10:in `<top (required)>'
    from /.rvm/gems/ruby-2.0.0-p353/bin/puma:23:in `load'
    from /.rvm/gems/ruby-2.0.0-p353/bin/puma:23:in `<main>'
    from /.rvm/gems/ruby-2.0.0-p353/bin/ruby_executable_hooks:15:in `eval'
    from /.rvm/gems/ruby-2.0.0-p353/bin/ruby_executable_hooks:15:in `<main>'

Answer 1

you need use kill -9 59780 (use lsof -wni tcp:3000 to see which process used 3000 port and get the process pid)

or you just modify your puma config change the tcp port tcp://127.0.0.1:3000 from 3000 to 9292 or other port that not been used.

or you can start your rails app by using

bundle exec puma -C config/puma.rb -b tcp://127.0.0.1:3001

Answer 2

To kill the puma process first run

    lsof -wni tcp:3000 

to show what is using port 3000. Then use the PID that comes with the result to run the kill process.

For example after running lsof -wni tcp:3000 you might get something like

    COMMAND  PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
    ruby    3366 dummy    8u  IPv4  16901      0t0  TCP 127.0.0.1:3000 (LISTEN)

Now run the following to kill the process. (where 3366 is the PID)

kill -9 3366

Should resolve the issue

Answer 3

you can also try this trick:

ps aux | grep puma

sample output:

myname           77921   0.0  0.0  2433828   1972 s000  R+   11:17AM   0:00.00 grep puma
myname           67661   0.0  2.3  2680504 191204 s002  S+   11:00AM   0:18.38 puma 3.11.2 (tcp://localhost:3000) [my_proj]

then:

kill 67661

Answer 4

Found the script below in this github issue. Works great for me.

#!/usr/bin/env ruby
port = ARGV.first || 3000
system("sudo echo kill-server-on #{port}")

pid = `sudo lsof -iTCP -sTCP:LISTEN -n -P | grep #{port} | awk '{ print $2 }' | head -n 1`.strip
puts "PID: #{pid}"
`kill -9 #{pid}` unless pid.empty?

You can either run it in irb or inside a ruby file.

For the latter, create server_killer.rb then run it with ruby server_killer.rb