Bg

Non-blocking ActiveRecord method invocation

This library allows you to invoke ActiveRecord instance methods in the background.

• Bg::Asyncable uses concurrent-ruby to execute methods in a different thread
• Bg::Deferrable uses ActiveJob to execute methods in a background process

Quickstart

Setup

class User < ApplicationRecord
  include Bg::Asyncable  # uses concurrent-ruby
  include Bg::Deferrable # uses ActiveJob
end

Usage

user = User.find(params[:id])
user.do_hard_work       # blocking in-process
user.async.do_hard_work # non-blocking in-process
user.defer.do_hard_work # non-blocking out-of-process background job
user.defer(queue: :low, wait: 5.minutes).do_hard_work

Provisos

Bg leverages GlobalID to marshal ActiveRecord instances across thread & process boundaries. This means that state is not shared between the main process/thread with the process/thread actually executing the method.

• Do not depend on lexically scoped bindings when invoking methods with Bg::Deferrable
• Do not pass unmarshallable types as arguments with Bg::Deferrable. Follow Sidekiq's simple parameters rule

Examples

Good

user = User.find(params[:id])
user.update(name: "new value") # persisted changes will be available in Bg invoked methods

user.async.do_hard_work 1, true, "foo", :bar, Time.now
user.defer.do_hard_work 1, true, "foo"

Bad

user = User.find(params[:id])
user.name = "new value" # in memory changes will not be available in Bg invoked methods

user.async.do_hard_work do
  # blocks are not supported
end

user.defer.do_hard_work :foo, Time.now # args won't marshal properly

user.defer.do_hard_work do
  # blocks are not supported
end