Resque::Serializer
A Resque plugin which ensures for a given queue, that only one worker is executing a job at any given time.
It is slightly more flexible than Resque::LonelyJob.
This gem may be helpful to avoid database lock contention.
Installation
Add this line to your application's Gemfile:
gem 'resque-serializer'
And then execute:
$ bundle
Or install it yourself as:
$ gem install resque-serializer
Usage
TLDR
| Lock Lifetime | :queue | :job | :both | :combined |
| -------------: | :----: | :---: | :----: | :-------: |
| before_enqueue | ✓ | | ✓ | ✓ |
| enqueue | | | | | | | |
| after_enqueue | | | | | | | |
| before_dequeue | | | ✓ | | ✓ | | |
| dequeue | | | | | | | | | |
| after_dequeue | ✗ | | | ✗ | | | |
| before_perform | | | | | | | |
| perform | | | | | | | |
| after_perform | | ✗ | ✗ | ✗ |
Example #1 -- Serializing the queue
require 'resque-serializer'
class SerializedJob
extend Resque::Plugins::Serializer
@queue = :default
serialize :queue
def self.perform
# work
end
end
Only one of job with identical arguments will be allowed to be queued at a time. As soon as the job is dequeued to begin executing, an identical job may be queued (and may begin executing.)
Example #2 -- Serializing the job
require 'resque-serializer'
class SerializedJob
extend Resque::Plugins::Serializer
@queue = :default
serialize :job
def self.perform
# work
end
end
Any number of these jobs may be queued, but only one job with identical arguments will be executed at a time. As soon as the executing job is completed, another queued job may be dequeued to execute.
Example #3 -- Serializing both the queue & job (independently)
require 'resque-serializer'
class SerializedJob
extend Resque::Plugins::Serializer
@queue = :default
serialize :both
def self.perform
# work
end
end
A combination of the first two examples; both the queue and the execution of identical jobs is serialized (independently.) An additional job may be queued if no identical job exists in the queue. Similarly, an additional job may begin executing if no identical job is currently executing.
Example #4 -- Serializing both the queue & job (combined)
require 'resque-serializer'
class SerializedJob
extend Resque::Plugins::Serializer
@queue = :default
serialize :combined
def self.perform
# work
end
end
Also a combination of the first two examples; both the queue and execution of identical jobs is serialized (together.) An additional job may not be queued if an identical job exists in the queue or execution.
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Added some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request
License
The gem is available as open source under the terms of the MIT License.