Boatload is a gem for enqueueing a bunch of work and then asynchronously processing it all in one go. Consider the following example:

You have a Rails app and you want to write something to Kafka for every request. It's important to make the network call to Kafka asynchronously because it might take a while and in the meantime you don't want to block the request from being served. At the same time, making a separate call to Kafka for each request served by your app is inefficient. Instead, you want to batch up a bunch of data and send it all at once.

This is a common use case for Kafka so the ruby-kafka library provides an AsyncProducer class to do exactly that. This gem provides the same functionality but removes all the Kafka-specific stuff and allows you to define for yourself what "processing a batch" looks like. So if you want to write to some other datastore or do something else entirely, you're free to do so.


Add this line to your application's Gemfile:

gem 'boatload'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install boatload


A basic example where we manually decide when to kick off a batch process:

abp = { |items| puts items }

abp.push 1
abp.push 2
# ...

# This will call the process block asynchronously with all the items that have been pushed

We can specify a max_backlog_size to automatically trigger a batch process once a certain number of items have been pushed:

abp = 5) { |items| puts items }

abp.push 1, 2, 3, 4

# A batch process will be triggered automatically once 5 is pushed
abp.push 5

We can also specify a delivery_interval to automatically trigger a batch process periodically:

abp = 30) { |items| puts items }

abp.push 1, 2, 3

# Every 30 seconds, a batch process will automatically be triggered

For maximal robustitude, consider using max_backlog_size and delivery_interval in conjunction with one another.


After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to


Bug reports and pull requests are welcome on GitHub at