Switchman + Instructure Jobs Compatibility Gem
If you are using the Switchman and Instructure Jobs gems in your application, simply include this gem to make background jobs aware of sharding.
Some high-level features this gem provides to make this work:
- Awareness on the Switchman side (inside shards) that shards have associated DJ shards that need to be activated when trying to talk to the DJ tables (lib/switchman_inst_jobs/switchman)
- Awareness on the DJ side that jobs run within a given shard context that can be loaded from the config and need to activate the shards jobs live on before running (lib/switchman_inst_jobs/delayed)
Requirements
- Ruby 2.7+
- Rails 6.1+
Installation
First ensure that you have installed both Switchman and Instucture Jobs gems, including their database migrations.
Add this line to your application's Gemfile:
gem 'switchman-inst-jobs'
And then execute:
bundle
Or install it yourself like so:
gem install switchman-inst-jobs
You will also want to install the database migration necessary to include the associated shard for any queued jobs:
bundle exec rake switchman_inst_jobs:install:migrations
bundle exec rake db:migrate
You can continue to use inst-jobs settings like you would normally. There is one inst-jobs setting you may want to configure in your application though:
Delayed::Settings.worker_procname_prefix = lambda do
"#{Switchman::Shard.current(Delayed::Job).id}~"
end
Development
A simple docker environment has been provided for spinning up and testing this gem with multiple versions of Ruby. This requires docker and docker-compose to be installed. To get started, run the following:
docker-compose build --pull
docker-compose up -d postgres
docker-compose run --rm app
This will install the gem in a docker image with all versions of Ruby installed, and install all gem dependencies in the Ruby 2.7 set of gems. It will also download and spin up a PostgreSQL container for use with specs.
The first build will take a long time, however, docker images and gems are cached, making additional runs significantly faster.
To run individual specs in a development workflow, you're going to want to have your file system mounted into the container:
cp docker-compose.override.example.yml docker-compose.override.yml
Then you're going to want to have a console open so that you can do a fast-feedback loop while making changes:
docker-compose run --rm app /bin/bash -l -c
# you're inside the container shell now
bundle install
bundle exec rspec
bundle exec rspec spec/lib/delayed/worker/health_check_spec.rb
Watch your tests fail, tweak things, run the spec again, etc.
Making a new Release
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 just
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
rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/instructure/switchman-inst-jobs.
License
The gem is available as open source under the terms of the MIT License.