ruby on rails - Resque.enqueue falla en la segunda ejecución

ruby-on-rails redis

Question

Estoy tratando de portar una aplicación de Rails 3.0.3 a Rails 3.1rc ... No creo que me haya perdido nada, en términos de configuración. El proceso funciona perfectamente en Rails 3.0.X y no en 3.1rc.

En la consola, hago:

Resque.enqueue(EncodeSong, Song.find(20).id, Song.find(20).unencoded_url)

Todo funciona hasta ahora. Resque-web no reporta trabajos fallidos. Y, obtengo las dos ''entradas'' del módulo EncodeSong.

Sin embargo, si ejecuta Resque.enqueue (EncodeSong, Song.find (20) .id, Song.find (20) .unencoded_url) por segunda vez, se mostrará el siguiente error en resque-web (a continuación). Para que el error desaparezca, tendría que cerrar el proceso que se está ejecutando: QUEUE = * rake environment resque: work y volver a ejecutarlo en la ventana de la consola. Pero el problema vuelve después de intentar Resque.enqueue () después de la primera vez.

Class
    EncodeSong
Arguments

    20
    "https://bucket_name.s3.amazonaws.com/unencoded/users/1/songs/test.mp3"

Exception
    PGError
Error
    server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request.

    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/postgresql_adapter.rb:272:in `exec''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/postgresql_adapter.rb:272:in `block in clear_cache!''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/postgresql_adapter.rb:271:in `each_value''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/postgresql_adapter.rb:271:in `clear_cache!''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/postgresql_adapter.rb:299:in `disconnect!''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:191:in `block in disconnect!''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:in `each''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:in `disconnect!''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activesupport-3.1.0.rc1/lib/active_support/core_ext/module/synchronization.rb:35:in `block in disconnect_with_synchronization!''
    /Users/Chris/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activesupport-3.1.0.rc1/lib/active_support/core_ext/module/synchronization.rb:34:in `disconnect_with_synchronization!''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:407:in `remove_connection''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:116:in `remove_connection''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:79:in `establish_connection''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:60:in `establish_connection''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:55:in `establish_connection''
    /Users/Chris/Sites/site_name/lib/tasks/resque.rake:17:in `block (2 levels) in <top (required)>''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/worker.rb:355:in `call''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/worker.rb:355:in `run_hook''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/worker.rb:162:in `perform''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/worker.rb:130:in `block in work''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/worker.rb:116:in `loop''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/worker.rb:116:in `work''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/resque-1.16.1/lib/resque/tasks.rb:27:in `block (2 levels) in <top (required)>''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:205:in `call''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:205:in `block in execute''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:200:in `each''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:200:in `execute''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:158:in `block in invoke_with_call_chain''
    /Users/Chris/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:151:in `invoke_with_call_chain''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/task.rb:144:in `invoke''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:112:in `invoke_task''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:90:in `block (2 levels) in top_level''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:90:in `each''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:90:in `block in top_level''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:129:in `standard_exception_handling''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:84:in `top_level''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:62:in `block in run''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:129:in `standard_exception_handling''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/lib/rake/application.rb:59:in `run''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/gems/rake-0.9.0/bin/rake:31:in `<top (required)>''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/bin/rake:19:in `load''
    /Users/Chris/.rvm/gems/ruby-1.9.2-p136@railspre/bin/rake:19:in `<main>''

Aquí está el resto de mi código relevante:

/config/initializers/resque.rb

require ''resque''

uri = URI.parse(APP_CONFIG[''redis_to_go_url''])
Resque.redis = Redis.new(:host => uri.host, :port => uri.port, :password => uri.password)

# Load all jobs at /app/jobs
Dir["#{Rails.root}/app/jobs/*.rb"].each { |file| require file }

/app/jobs/encode_song.rb

module EncodeSong
  @queue = :encode_song

  def self.perform(media_id, s3_file_url)
    begin
      media = Song.find(media_id)
      puts ''foo11111''
      puts media.id
    rescue
      puts "Error #{$!}"
    end
  end
end

lib / tasks / resque.rake

require ''resque/tasks''

task "resque:setup" => :environment do
  ENV[''QUEUE''] = ''*''

  # ONLY on Heroku, since they are still running PostgreSql 8 on their shared plan.
  # This block of code is not needed on PostgreSql 9, as tested on local environment.
  # Issue: My best guess is that master resque process establishes connection to db,
  # while loading rails app classes, models, etc, and that connection becomes corrupted
  # in fork()ed process (on exit?). Possible fix is to reestablish the connection the AR
  # after a Resque fork.
  Resque.after_fork do |job|
    ActiveRecord::Base.establish_connection
  end

end

desc "Alias for resque:work (To run workers on Heroku)"
task "jobs:work" => "resque:work"

No muy seguro, pero puede estar algo relacionado con este issue . Mi conjetura es que el proceso de resque maestro establece la conexión a la base de datos, mientras se cargan las clases de aplicaciones de rieles, modelos, etc., y esa conexión se corrompe en el proceso de bifurcación () (¿en la salida?).

Cualquier ayuda / dirección será apreciada.

EDITAR:

Si elimino el siguiente bloque de lib / tasks / resque.rake :

  Resque.after_fork do |job|
    ActiveRecord::Base.establish_connection
  end

Y en la consola, ejecute Resque.enqueue (EncodeSong, Song.find (20) .id, Song.find (20) .unencoded_url)

Recibo un nuevo error (en la consola donde se ejecutó QUEUE = * rake environment resque: se ejecutó el trabajo):

Error PGError: ERROR:  prepared statement "a3" already exists
: SELECT  "songs".* FROM "songs"  WHERE "songs"."id" = $1 LIMIT 1

Parece que esto puede ser un error con el adaptador? Podría estar equivocado aquí. ¿Tus pensamientos?

Answer 1

Esto me lo ha resuelto:

require ''resque/tasks''

task "resque:setup" => :environment do
  ENV[''QUEUE''] = ''*''

  Resque.before_fork = Proc.new { ActiveRecord::Base.establish_connection }
end

Fuente: comentario carhartl sobre Github