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Diffstat (limited to 'guides/source/active_job_basics.md')
| -rw-r--r-- | guides/source/active_job_basics.md | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md index d8ea1ee079..c65d1e6de5 100644 --- a/guides/source/active_job_basics.md +++ b/guides/source/active_job_basics.md @@ -34,8 +34,9 @@ Delayed Job and Resque. Picking your queuing backend becomes more of an operatio concern, then. And you'll be able to switch between them without having to rewrite your jobs. -NOTE: Rails by default comes with an "immediate runner" queuing implementation. -That means that each job that has been enqueued will run immediately. +NOTE: Rails by default comes with an asynchronous queuing implementation that +runs jobs with an in-process thread pool. Jobs will run asynchronously, but any +jobs in the queue will be dropped upon restart. Creating a Job @@ -62,12 +63,12 @@ $ bin/rails generate job guests_cleanup --queue urgent ``` If you don't want to use a generator, you could create your own file inside of -`app/jobs`, just make sure that it inherits from `ActiveJob::Base`. +`app/jobs`, just make sure that it inherits from `ApplicationJob`. Here's what a job looks like: ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :default def perform(*guests) @@ -109,7 +110,7 @@ That's it! Job Execution ------------- -For enqueuing and executing jobs in production you need to set up a queuing backend, +For enqueuing and executing jobs in production you need to set up a queuing backend, that is to say you need to decide for a 3rd-party queuing library that Rails should use. Rails itself only provides an in-process queuing system, which only keeps the jobs in RAM. If the process crashes or the machine is reset, then all outstanding jobs are lost with the @@ -138,6 +139,18 @@ module YourApp end ``` +You can also configure your backend on a per job basis. + +```ruby +class GuestsCleanupJob < ApplicationJob + self.queue_adapter = :resque + #.... +end + +# Now your job will use `resque` as it's backend queue adapter overriding what +# was configured in `config.active_job.queue_adapter`. +``` + ### Starting the Backend Since jobs run in parallel to your Rails application, most queuing libraries @@ -159,7 +172,7 @@ Most of the adapters support multiple queues. With Active Job you can schedule the job to run on a specific queue: ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -177,7 +190,7 @@ module YourApp end # app/jobs/guests_cleanup_job.rb -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -200,7 +213,7 @@ module YourApp end # app/jobs/guests_cleanup_job.rb -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -222,7 +235,7 @@ block will be executed in the job context (so you can access `self.arguments`) and you must return the queue name: ```ruby -class ProcessVideoJob < ActiveJob::Base +class ProcessVideoJob < ApplicationJob queue_as do video = self.arguments.first if video.owner.premium? @@ -262,7 +275,7 @@ trigger logic during the life cycle of a job. ### Usage ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :default before_enqueue do |job| @@ -319,7 +332,7 @@ Active Record objects to your job instead of class/id pairs, which you then have to manually deserialize. Before, jobs would look like this: ```ruby -class TrashableCleanupJob < ActiveJob::Base +class TrashableCleanupJob < ApplicationJob def perform(trashable_class, trashable_id, depth) trashable = trashable_class.constantize.find(trashable_id) trashable.cleanup(depth) @@ -330,7 +343,7 @@ end Now you can simply do: ```ruby -class TrashableCleanupJob < ActiveJob::Base +class TrashableCleanupJob < ApplicationJob def perform(trashable, depth) trashable.cleanup(depth) end @@ -348,7 +361,7 @@ Active Job provides a way to catch exceptions raised during the execution of the job: ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :default rescue_from(ActiveRecord::RecordNotFound) do |exception| |