# SidekiqUniqueJobs [![Join the chat at https://gitter.im/mhenrixon/sidekiq-unique-jobs](https://badges.gitter.im/mhenrixon/sidekiq-unique-jobs.svg)](https://gitter.im/mhenrixon/sidekiq-unique-jobs?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Build Status](https://travis-ci.org/mhenrixon/sidekiq-unique-jobs.png?branch=master)](https://travis-ci.org/mhenrixon/sidekiq-unique-jobs) [![Code Climate](https://codeclimate.com/github/mhenrixon/sidekiq-unique-jobs.png)](https://codeclimate.com/github/mhenrixon/sidekiq-unique-jobs) [![Test Coverage](https://codeclimate.com/github/mhenrixon/sidekiq-unique-jobs/badges/coverage.svg)](https://codeclimate.com/github/mhenrixon/sidekiq-unique-jobs/coverage)

The missing unique jobs for sidekiq

## Documentation

This is the documentation for the master branch. You can find the documentation for each release by navigating to its tag: https://github.com/mhenrixon/sidekiq-unique-jobs/tree/v5.0.10.

Below are links to the latest major versions (4 & 5):

- [v5.0.10](https://github.com/mhenrixon/sidekiq-unique-jobs/tree/v5.0.10)
- [v4.0.18](https://github.com/mhenrixon/sidekiq-unique-jobs/tree/v4.0.18)

## Requirements

See https://github.com/mperham/sidekiq#requirements for what is required. Starting from 5.0.0 only sidekiq >= 4 is supported and support for MRI <= 2.1 is dropped. ActiveJob is not supported

Version 6 requires Redis >= 3 and pure Sidekiq, no ActiveJob supported anymore. See [About ActiveJob](https://github.com/mhenrixon/sidekiq-unique-jobs/wiki/About-ActiveJob) for why.

## Installation

Add this line to your application's Gemfile:

    gem 'sidekiq-unique-jobs'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install sidekiq-unique-jobs

## General Information

See [Interaction w/ Sidekiq](https://github.com/mhenrixon/sidekiq-unique-jobs/wiki/How-this-gem-interacts-with-Sidekiq) on how the gem interacts with Sidekiq.

See [Locking & Unlocking](https://github.com/mhenrixon/sidekiq-unique-jobs/wiki/Locking-&-Unlocking) for an overview of the differences on when the various lock types are locked and unlocked.

### Options

#### Lock Expiration

This is probably not the configuration option you want...

Since the client and the server are disconnected and not running inside the same process, setting a lock expiration is probably not what you want. Any keys that are used by this gem WILL be removed at the time of the expiration. For jobs that are scheduled in the future the key will expire when that job is scheduled + whatever expiration you have set.

In previous versions there was a default expiration of 30 minutes which didn't work for a lot of long running jobs. Since version 6 there will be no expiration of any jobs from the default configuration. Please don't use `lock_expiration` unless you really know what you are doing.

```ruby
sidekiq_options lock_expiration: nil # default - don't expire keys
sidekiq_options lock_expiration: 20.days # expire this lock in 20 days
```

#### Lock Timeout

This is the timeout (how long to wait) when creating the lock. By default we don't use a timeout so we won't wait for the lock to be created. If you want it is possible to set this like below.

```ruby
sidekiq_options lock_timeout: 0 # default - don't wait at all
sidekiq_options lock_timeout: 5 # wait 5 seconds
sidekiq_options lock_timeout: nil # lock indefinitely, this process won't continue until it gets a lock. VERY DANGEROUS!!
```

#### Unique Across Queues

This configuration option is slightly misleading. It doesn't disregard the queue on other jobs. Just on itself, this means that a worker that might schedule jobs into multiple queues will be able to have uniqueness enforced on all queues it is pushed to.

```ruby
class Worker
  include Sidekiq::Worker
  
  sidekiq_options: unique_across_queues: true, queue: 'default'

  def perform(args); end
end
```

Now if you push override the queue with `Worker.set(queue: 'another').perform_async(1)` it will still be considered unique when compared to `Worker.perform_async(1)` (that was actually pushed to the queue `default`).

#### Unique Across Workers

This configuration option is slightly misleading. It doesn't disregard the worker class on other jobs. Just on itself, this means that a worker that the worker class won't be used for generating the unique digest. The only way this option really makes sense is when you want to have uniqueness between two different worker classes.

```ruby
class WorkerOne
  include Sidekiq::Worker
  
  sidekiq_options: unique_across_workers: true, queue: 'default'

  def perform(args); end
end

class WorkerTwo
  include Sidekiq::Worker
  
  sidekiq_options: unique_across_workers: true, queue: 'default'

  def perform(args); end
end


WorkerOne.perform_async(1) 
# => 'the jobs unique id'

WorkerTwo.perform_async(1) 
# => nil because WorkerOne just stole the lock
```

### Locks

####

### Until Executing

Locks from when the client pushes the job to the queue. Will be unlocked before the server starts processing the job.

**NOTE** this is probably not so good for jobs that shouldn't be running simultaneously (aka slow jobs).

```ruby
sidekiq_options unique: :until_executing
```

### Until Executed

Locks from when the client pushes the job to the queue. Will be unlocked when the server has successfully processed the job.

```ruby
sidekiq_options unique: :until_executed
```

### Until Timeout

Locks from when the client pushes the job to the queue. Will be unlocked when the specified timeout has been reached.

```ruby
sidekiq_options unique: :until_expired
```

### Unique Until And While Executing

Locks when the client pushes the job to the queue. The queue will be unlocked when the server starts processing the job. The server then goes on to creating a runtime lock for the job to prevent simultaneous jobs from being executed. As soon as the server starts processing a job, the client can push the same job to the queue.

```ruby
sidekiq_options unique: :until_and_while_executing
```

### While Executing

With this lock type it is possible to put any number of these jobs on the queue, but as the server pops the job from the queue it will create a lock and then wait until other locks are done processing. It _looks_ like multiple jobs are running at the same time but in fact the second job will only be waiting for the first job to finish.

**NOTE** Unless this job is configured with a `lock_timeout: nil` or `lock_timeout: > 0` then all jobs that are attempted to be executed will just be dropped without waiting.

```ruby
sidekiq_options unique: :while_executing, lock_timeout: nil
```

There is an example of this to try it out in the `rails_example` application. Run `foreman start` in the root of the directory and open the url: `localhost:5000/work/duplicate_while_executing`.

In the console you should see something like:

```
0:32:24 worker.1 | 2017-04-23T08:32:24.955Z 84404 TID-ougq4thko WhileExecutingWorker JID-400ec51c9523f41cd4a35058 INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.956Z 84404 TID-ougq8csew WhileExecutingWorker JID-8d6d9168368eedaed7f75763 INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.957Z 84404 TID-ougq8crt8 WhileExecutingWorker JID-affcd079094c9b26e8b9ba60 INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.959Z 84404 TID-ougq8cs8s WhileExecutingWorker JID-9e197460c067b22eb1b5d07f INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.959Z 84404 TID-ougq4thko WhileExecutingWorker JID-400ec51c9523f41cd4a35058 WhileExecutingWorker INFO: perform(1, 2)
10:32:34 worker.1 | 2017-04-23T08:32:34.964Z 84404 TID-ougq4thko WhileExecutingWorker JID-400ec51c9523f41cd4a35058 INFO: done: 10.009 sec
10:32:34 worker.1 | 2017-04-23T08:32:34.965Z 84404 TID-ougq8csew WhileExecutingWorker JID-8d6d9168368eedaed7f75763 WhileExecutingWorker INFO: perform(1, 2)
10:32:44 worker.1 | 2017-04-23T08:32:44.965Z 84404 TID-ougq8crt8 WhileExecutingWorker JID-affcd079094c9b26e8b9ba60 WhileExecutingWorker INFO: perform(1, 2)
10:32:44 worker.1 | 2017-04-23T08:32:44.965Z 84404 TID-ougq8csew WhileExecutingWorker JID-8d6d9168368eedaed7f75763 INFO: done: 20.009 sec
10:32:54 worker.1 | 2017-04-23T08:32:54.970Z 84404 TID-ougq8cs8s WhileExecutingWorker JID-9e197460c067b22eb1b5d07f WhileExecutingWorker INFO: perform(1, 2)
10:32:54 worker.1 | 2017-04-23T08:32:54.969Z 84404 TID-ougq8crt8 WhileExecutingWorker JID-affcd079094c9b26e8b9ba60 INFO: done: 30.012 sec
10:33:04 worker.1 | 2017-04-23T08:33:04.973Z 84404 TID-ougq8cs8s WhileExecutingWorker JID-9e197460c067b22eb1b5d07f INFO: done: 40.014 sec
```

## Usage

All that is required is that you specifically set the sidekiq option for _unique_ to a valid value like below:

```ruby
sidekiq_options unique: :while_executing
```

Requiring the gem in your gemfile should be sufficient to enable unique jobs.

### Finer Control over Uniqueness

Sometimes it is desired to have a finer control over which arguments are used in determining uniqueness of the job, and others may be _transient_. For this use-case, you need to define either a `unique_args` method, or a ruby proc.

The unique_args method need to return an array of values to use for uniqueness check.

The method or the proc can return a modified version of args without the transient arguments included, as shown below:

```ruby
class UniqueJobWithFilterMethod
  include Sidekiq::Worker
  sidekiq_options unique: :until_and_while_executing,
                  unique_args: :unique_args # this is default and will be used if such a method is defined

  def self.unique_args(args)
    [ args[0], args[2][:type] ]
  end

  ...

end

class UniqueJobWithFilterProc
  include Sidekiq::Worker
  sidekiq_options unique: :until_executed,
                  unique_args: ->(args) { [ args.first ] }

  ...

end
```

It is also quite possible to ensure different types of unique args based on context. I can't vouch for the below example but see [#203](https://github.com/mhenrixon/sidekiq-unique-jobs/issues/203) for the discussion.

```ruby
class UniqueJobWithFilterMethod
  include Sidekiq::Worker
  sidekiq_options unique: :until_and_while_executing, unique_args: :unique_args

  def self.unique_args(args)
    if Sidekiq::ProcessSet.new.size > 1
      # sidekiq runtime; uniqueness for the object (first arg)
      args.first
    else
      # queuing from the app; uniqueness for all params
      args
    end
  end
end
```

### After Unlock Callback

If you need to perform any additional work after the lock has been released you can provide an `#after_unlock` instance method. The method will be called when the lock has been unlocked. Most times this means after yield but there are two exceptions to that. 

**Exception 1:** UntilExecuting unlocks and calls back before yielding.
**Exception 2:** UntilExpired expires eventually, no after_unlock hook is called.

```ruby
class UniqueJobWithFilterMethod
  include Sidekiq::Worker
  sidekiq_options unique: :while_executing,

  def after_unlock
   # block has yielded and lock is released
  end
  ...
end.
```

### Logging

To see logging in sidekiq when duplicate payload has been filtered out you can enable on a per worker basis using the sidekiq options. The default value is false

```ruby
class UniqueJobWithFilterMethod
  include Sidekiq::Worker
  sidekiq_options unique: :while_executing,
                  log_duplicate_payload: true

  ...

end
```

## Debugging

There are two ways to display and remove keys regarding uniqueness. The console way and the command line way.

### Console

Start the console with the following command `bundle exec uniquejobs console`.

#### List Unique Keys

`keys '*', 100`

#### Remove Unique Keys

`del '*', 100, false` the dry_run and count parameters are both required. This is to have some type of protection against clearing out all uniqueness.

### Command Line

`bundle exec uniquejobs` displays help on how to use the unique jobs command line.

## Communication

There is a [![Join the chat at https://gitter.im/mhenrixon/sidekiq-unique-jobs](https://badges.gitter.im/mhenrixon/sidekiq-unique-jobs.svg)](https://gitter.im/mhenrixon/sidekiq-unique-jobs?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) for praise or scorn. This would be a good place to have lengthy discuss or brilliant suggestions or simply just nudge me if I forget about anything.

## Testing

This has been probably the most confusing part of this gem. People get really confused with how unreliable the unique jobs have been. I there for decided to do what Mike is doing for sidekiq enterprise. Read the section about unique jobs.

https://www.dailydrip.com/topics/sidekiq/drips/sidekiq-enterprise-unique-jobs

```ruby
SidekiqUniqueJobs.configure do |config|
  config.enabled = !Rails.env.test?
end
```

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request

## Contributors

In no particular order:

- https://github.com/salrepe
- https://github.com/rickenharp
- https://github.com/sax
- https://github.com/eduardosasso
- https://github.com/KensoDev
- https://github.com/adstage-david
- https://github.com/jprincipe
- https://github.com/crberube
- https://github.com/simonoff