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ruby-on-railspuma

Cannot run localhost:3000 : white empty page is rendered


I am using Rails 4.2.6 and Ruby 2.3.0 and Puma 3.3.0 During the last couple days I ran some bundle update and after rails s all browsers for the same URL localhost:3000 are rendering the same blank page. This is consistent for all 6-7 applications I am playing with. However all are working in "production" when deployed to Heroku. Seems to be only a matter related to my dev env.

Don't know how to solve this. Any help will be much appreciated. Can't continue development if can't run unit tests on the code I am developing.

However all works well when I am using another port. For example when starting the app server with the command rails s -p 3001 or port 3002 I have no problems to run the apps in any browser using the URL localhost:3001 or localhost:3002.

What is wrong with my 3000 port or Puma or both?


Solution

  • It may happen in locally in dev and never in "prod" i.e. Heroku due to a bug when stopping Puma. Some times some processes are not killed due to:

    levi-test-01 liviu-mac $ rails s
    => Booting Puma
    => Rails 4.2.6 application starting in development on http://localhost:3000
    => Run `rails server -h` for more startup options
    => Ctrl-C to shutdown server
    [4589] Puma starting in cluster mode...
    [4589] * Version 3.3.0 (ruby 2.3.0-p0), codename: Jovial Platypus
    [4589] * Min threads: 5, max threads: 5
    [4589] * Environment: development
    [4589] * Process workers: 2
    [4589] * Preloading application
    [4589] * Listening on tcp://localhost:3000
    [4589] Use Ctrl-C to stop
    [4589] - Worker 1 (pid: 4603) booted, phase: 0
    [4589] - Worker 0 (pid: 4602) booted, phase: 0
    ^C[4589] - Gracefully shutting down workers...
    /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/rack-1.6.4/lib/rack/server.rb:355:in `delete': No such file or directory @ unlink_internal - /Users/liviu-mac/ror/levi-test-01/tmp/pids/server.pid (Errno::ENOENT)
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/rack-1.6.4/lib/rack/server.rb:355:in `block in write_pid'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/puma/cluster.rb:120:in `fork'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/puma/cluster.rb:120:in `block in spawn_workers'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/puma/cluster.rb:116:in `times'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/puma/cluster.rb:116:in `spawn_workers'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/puma/cluster.rb:418:in `run'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/puma/launcher.rb:172:in `run'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/puma-3.3.0/lib/rack/handler/puma.rb:51:in `run'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/rack-1.6.4/lib/rack/server.rb:286:in `start'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/railties-4.2.6/lib/rails/commands/server.rb:80:in `start'
        from /Users/liviu-mac/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:80:in `block in server'
    

    Running a command like this:

    levi-test-01 liviu-mac $ lsof -i :3000
    

    lists all remaining processes using port 3000.

    A command like

    levi-test-01 liviu-mac $ kill -9 PID
    

    solves the problem.