Relation randomly raises ActiveRecord::RecordNotFound - ruby-on-rails

Question

Once in a while when trying to fetch an order record for a particular user, a ActiveRecord::RecordNotFound is raised.
Some things to note here.
The error is raised when visiting /orders/:id, but not for all users. We track completed orders (meaning that you end up on a orders page) and around 50% gets a 404. Note that we're talking about 50% of the users, not the requests. If it displays 404 once for an order for a particular user, it will always display a 404.
The record exists as it can be accessed via the console using the same data that's being logged in the controller.
The problem disappears when re-deploying the application.
What could the problem be?
I'm running rails 4.2.0.
class OrdersController < ApplicationController
#
# GET /orders/:id
#
def show
Rails.logger.info "current_user=#{current_user.id}, params[:id]=#{params[:id]}"
#order = current_user.orders.find(params[:id])
end
end
class ApplicationController < ActionController::Base
def current_user
#_current_user ||= User.find_by_id(cookies.signed[:uid])
end
end
class User < ActiveRecord::Base
has_many :subscriptions
has_many :orders, through: :subscriptions
end
class Order < ActiveRecord::Base
has_one :user, through: :subscription
end
class Subscription < ActiveRecord::Base
belongs_to :user
end
Here's the log output
[User#id=2454266] Parameters: {"id"=>"1553"}
[User#id=2454266] current_user=2454266, params[:id]=1553 <==== Rails.logger.info
[User#id=2454266] Completed 404 Not Found in 240ms
[User#id=2454266]
ActiveRecord::RecordNotFound (Couldn't find Order with 'id'=1553):
app/controllers/orders_controller.rb:6:in `show'
Running User.find(2454266).orders.find(1553) in the console works.
Also note that it's possible to skip the relation and go directly to the order model, like this
class OrdersController < ApplicationController
#
# GET /orders/:id
#
def show
#order = Order.find(params[:id])
end
end

Answer 1

The way we arrived at the conclusion can be found by going through the comments list.
Our summary of findings are:
Either orders are cached, or current_user is outdated (along with cached associations)
Going straight to order works (i.e. Order.find / User.find(current_user.id).orders...
Solution that we arrived at is:
current_user.reload!
Before performing
current_user.orders.find(params[:id])

Answer 2

class ApplicationController < ActionController::Base
def current_user
#_current_user ||= User.find_by_id(cookies.signed[:uid])
end
def user_signed_in?
#_current_user.present?
end
end
class OrdersController < ApplicationController
def show
if user_signed_in?
#order = current_user.orders.find(params[:id])
else
return redirect_to <404 page or any>, alert: 'Order not found'
end
end
end
I think you have to check the presence of the user first, then you can trace the bug
I usually use this method when I got some issue
def show
if user_signed_in?
begin
#order = current_user.orders.find(params[:id])
rescue => e
binding.pry
end
else
return redirect_to <404 page or any>, alert: 'Order not found'
end
end
but you need 'rails-pry' gem, the advantage is rails will fire up rails console when there is exception