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Diffstat (limited to 'guides/source/active_job_basics.md')
| -rw-r--r-- | guides/source/active_job_basics.md | 42 |
1 files changed, 28 insertions, 14 deletions
diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md index 76c13f0ea9..c9f70dc87b 100644 --- a/guides/source/active_job_basics.md +++ b/guides/source/active_job_basics.md @@ -62,12 +62,12 @@ $ 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) @@ -109,10 +109,12 @@ That's it! Job Execution ------------- -For enqueuing and executing jobs 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 does not provide a sophisticated queuing system and just executes the -job immediately if no adapter is set. +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 +default async back-end. This may be fine for smaller apps or non-critical jobs, but most +production apps will need to pick a persistent backend. ### Backends @@ -136,6 +138,18 @@ 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 @@ -157,7 +171,7 @@ 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 @@ -175,7 +189,7 @@ module YourApp end # app/jobs/guests_cleanup_job.rb -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -198,7 +212,7 @@ module YourApp end # app/jobs/guests_cleanup_job.rb -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -220,7 +234,7 @@ 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? @@ -260,7 +274,7 @@ 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| @@ -317,7 +331,7 @@ 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) @@ -328,7 +342,7 @@ end Now you can simply do: ```ruby -class TrashableCleanupJob < ActiveJob::Base +class TrashableCleanupJob < ApplicationJob def perform(trashable, depth) trashable.cleanup(depth) end @@ -346,7 +360,7 @@ 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| |