Rails *Completed 406 Not Acceptable" in production ..working in Staging

Question

I am stuck with an error " Completed 406 Not Acceptable " in the production server which I am not facing in the staging server .

Same code is working fine in staging but not working in production .Both environment has same gems installed . I am using a rails version 3.0.10.

In my production environment , the GET request is processed as a html but in staging it is processed as js .I have defined the respond_to block only for js format . I am not sure why it is behaving differently in two environments.

Also I have tried adding the defaults format as js in the routes.rb but that also is not working.

match 'releases/cycle_paginate', :to => 'releases#cycle_paginate', :defaults => { :format => 'js' }

But this is also not working .

Below is the log for production and staging .

Production:

Started GET "/releases/cycle_paginate/2?id=4" for 10.30.10.67 at Wed Aug 14 07:13:45 -0400 2013
  Processing by ReleasesController#cycle_paginate as JS
  Parameters: {"id"=>"4", "page"=>"2"}

Staging:

Started GET "/releases/cycle_paginate/2?id=53" for 10.30.10.67 at Wed Aug 14 06:42:45 -0400 2013
  Processing by ReleasesController#cycle_paginate as HTML
  Parameters: {"id"=>"53", "page"=>"2"}

Controller:

def cycle_paginate

  @release = Release.find(params[:id])

  @cycles = []
  @cycles = Kaminari.paginate_array(@release.cycles) \
                  .page(params[:page]) \
                  .per(5)
  last_page = @cycles.num_pages
  if params[:page].to_i > last_page
    @cycles = @cycles.page(last_page)
  else
    @cycles = @cycles.page(params[:page].presence || 1)
  end
  respond_to do |format|
    format.js
  end
end

This is making me mad. Appreciate your help.

Routes.rb

    `Tcm::Application.routes.draw do        match "login", :controller => "user_sessions", :action => "create", :as => "login"
      match "logout", :controller => "user_sessions", :action => "destroy", :as => "logout"
      resources :ic_tree_items do
        get :children, :on => :member
        get :nonmem_rel_children, :on => :member
        get :release_children, :on => :member
        get :cycle_children, :on => :member
      end
      resources :users
      resources :ic_revisions
      resources :tester_release_assignments
      resources :roles
      resources :project_platform_config_assignments
      resources :platform_configs
      resources :user_sessions

      match 'ic_runs/execute_multiple', :to => 'IcRuns#execute_multiple', :as => "execute_multiple_ics", :via => :put

      resources :ic_runs
      resources :reports
      resources :testruns

      match "cycles/add_ics", :to => "cycles#add_ics"

      resources :cycles
      resources :releases do
        get :autocomplete_user_name, :on => :collection
      end
      resources :projects
      resources :tasks
      resources :steps
      resources :asserts

      match 'releases/mass_assign', :to => 'Releases#mass_assign', :as => 'mass_assign_releases', :via => :post
      match 'ics/mass_action', :to => 'Ics#mass_action', :as => 'mass_action_ics', :via => :post
      match 'ics/filter' ,:to=>'Ics#filter',:via=> :post
      match 'taggings/selection_options', :to => 'Taggings#selection_options', :as => 'selection_option_taggings',:via => :post
      match 'tags/filter',:to=>'Tags#filter',:via=> :post
      resources :ics
      resources :tags

      root :to => "Home#index"
      match ':name' => 'Projects#show'
      match 'ic_revisions/update', :to => 'ic_revisions#update'
      match 'ic_revisions/clone_task', :action => "clone_task", :controller=>"ic_revisions"
      match 'ic_revisions/definition_textbox', :to => 'ic_revisions#definition_textbox'
      match 'tasks/destroy', :action => "destroy", :controller=>"tasks"
      match 'steps/destroy', :action => "destroy", :controller=>"steps"
      match 'asserts/destroy', :action => "destroy", :controller=>"asserts"
      match 'cycles/:id/delete', :action => "destroy", :controller=>"cycles"
      match 'ic_revisions/manage/:ic_id', :to => 'ic_revisions#index', :as => "manage_ic_revisions"
      match 'cycles/:id/add_ics', :to => 'cycles#add_ics'
      match 'cycles/del_cycle_ic', :to => 'cycles#del_cycle_ic'
      match 'cycles/add_ic_run', :action => "add_ic_run", :controller=>"cycles", :via => :post
      match 'releases/:id/add_ics', :to => 'releases#add_ics'
      match 'users/lead/:id', :to => 'users#show_lead', :as => "lead"
      match 'users/tester/:id', :to => 'users#show_tester', :as => 'tester'
      match 'users/edit/:id', :to => 'users#edit', :as => 'users_edit'
      match 'cycles/add_cq', :to => 'cycles#add_cq',:as=>'cycles_add_cq'
      match 'ic_runs/update_ics', :to => 'ic_runs#update_ics'
      match 'ic_runs/cycle/:cycle_id', :to => 'ic_runs#cycle', :as => 'cycle_ic_runs'
      match 'ic_runs/edit_result', :to => 'ic_runs#edit_result'
      match 'ic_runs/ic_run_list/:id', :to => 'ic_runs#ic_run_list', :as => 'ic_runs_list'
      match 'reports',:to=>'reports#index'
      match 'reports/update_releases', :to=>'reports#update_releases'
      match 'reports/update_cycles', :to=>'reports#update_cycles'
      match 'reports/show', :to=> 'reports#export_reports'
      match 'ics/on_update_root', :to=>'ics#on_update_root'
      match 'ic_runs/export_all', :to => 'ic_runs#export_all'
      match 'ics/on_update_suite', :to=>'ics#on_update_suite'
      match 'ic_runs/destroy', :to => 'ic_runs#destroy', :key=>:ic_run_ids
      match 'cycles/:id/clone', :action => "clone", :controller=>"cycles"
      match 'releases/:id/clone', :action => "clone", :controller=>"releases"
      match 'cycles/:id/delete_ics', :action => "delete_ics", :controller=>"cycles"
      match 'releases/update_testers', :to => 'releases#update_testers'
      match 'releases/update_testers(/:page)', :action => "update_testers", :controller=>"Releases", :page => :page
      match 'releases/cycle_paginate', :to => 'releases#cycle_paginate'
      match 'releases/cycle_paginate(/:page)', :action => "cycle_paginate", :controller=>"Releases", :page => :page
      match 'ics/new_ics', :to =>'ics#', :action => "new_ics", :controller => "Ics"
      match 'ics/obsolete_ics', :to=>'ics#', :action=>"obsolete_ics", :controller=>"Ics"
      match 'ics/new_ic_stub', :to=>'ics#', :action=>"new_ic_stub", :controller=>"Ics"
      match 'ics/index', :to=>'ics#', :action=>"index", :controller=>"Ics"
      match 'releases/rel_all_ics', :action => "rel_non_member", :controller => "Releases"
      match 'cycles/cycle_non_member', :action=>"cycle_non_member", :controller=>"Cycles"
    end

`

Answer 1

Finally I got the solution after a lot of debugging ..

My request accept header was expecting a HTML while server was returning a Javascript response so that was not acceptable by browser.

In my case a Javascript file was missing the javascript_include_tag in the application.html.erb .The Javascript missing was jquery_ujs.js .Basically this sets the accept header for ajax loading .The Javascripts included in this tag will be cached and stored. So I added the missing Javascript and removed the cached folder and YIPPEE, my problem got resolved.

I will give a small example that I learnt somewhere from a blog. It seems that it will be helpful for others to understand the 406 error.

406 error can be understood as below: Suppose I've asked you for a book to read, but I can only read books in English and French. If you only have books in German, you would give me an empty response with a "406 - not acceptable" status.

406 is the server telling you "I have what you asked for, but you won't accept them".

That's what Accept headers in the http request are for. For instance, if the HTTP request includes directions that it will only accept "img/jpg" MIME type, the server would send a 406 status if the file requested is an Excel spreadsheet.

To diagnose:

• request one of these pages and analyze the http request headers
• Pay attention to the MIME type of the responses, the Character Set, GZIP encoding*

"406 not acceptable" is an unusual status code - the most common are 200, 404, 500, 301. You only see a 406 when something is wrong with the server, usually something silly but hard to diagnose.

Answer 2

I had the same problem. My issue was that I was making an HTML request, but my respond_to block was only accepting js.

so I needed to change this:

respond_to do |format|
  format.js
end

to this:

respond_to do |format|
  format.html
  format.js
end

And then it all worked again.