Use discard_on to discard the job with no attempts to retry

Discard the job with no attempts to retry, if the exception is raised. This is useful when the subject of the job, like an Active Record, is no longer available, and the job is thus no longer relevant.

You can also pass a block that'll be invoked. This block is yielded with the job instance as the first and the error instance as the second parameter.

*Example: 1*

```ruby
class SearchIndexingJob < ActiveJob::Base
  discard_on ActiveJob::DeserializationError
  discard_on(CustomAppException) do |job, error|
    ExceptionNotifier.caught(error)
  end

  def perform(record)
    # Will raise ActiveJob::DeserializationError if the record can't be deserialized
    # Might raise CustomAppException for something domain specific
  end
end
```

*Example: 2:*

```ruby
class UserNotFoundJob < ActiveJob::Base

  discard_on ActiveRecord::RecordNotFound



  def perform(user_id)

    @user = User.find(user_id)

    @user.do_some_thing

  end
end
```

[Source](https://twitter.com/stevepolitodsgn/status/1363164616944140288)

Victor Velazquez
February 20, 2021