ProcessBot

Run your app through ProcessBot for automatic restart if crashing, but still support normal deployment through Capistrano.

Watch memory usage for Sidekiq and restart gracefully if it exceeds a given limit (to counter memory leaks).

When deploying can gracefully exit Sidekiq to let long running jobs finish on old version of code, and start new Sidekiq processes after finishing deploy (but still let the old ones finish gracefully so nothing gets interrupted). This requires not to remove columns, rename columns or any other intrusive database changes.

Add this line to your application's Gemfile:

gem 'process_bot'

Add to your Capfile:

require "process_bot"
install_plugin ProcessBot::Capistrano::Sidekiq
install_plugin ProcessBot::Capistrano::Puma

Add to your deploy.rb:

after "deploy:starting", "process_bot:sidekiq:graceful"
after "deploy:published", "process_bot:sidekiq:start"
after "deploy:failed", "process_bot:sidekiq:start"

Run commands in the command line like this:

cap production process_bot:sidekiq:graceful

ProcessBot provides these Sidekiq tasks:

• process_bot:sidekiq:start
• process_bot:sidekiq:stop
• process_bot:sidekiq:graceful (stops fetching new jobs and waits for running jobs by default)
• process_bot:sidekiq:graceful_no_wait (stops fetching new jobs and returns immediately)
• process_bot:sidekiq:ensure_running (starts missing processes, including replacements for graceful shutdowns)
• process_bot:sidekiq:restart

You can also skip waiting for graceful completion:

cap production process_bot:sidekiq:graceful_no_wait

ProcessBot can log its internal actions (connecting, sending commands, signals, etc.) to stdout. Enable this with --log true (or --logging true):

bundle exec process_bot --command start --log true
bundle exec process_bot --command graceful --log true
bundle exec process_bot --command graceful_no_wait --log true

To write logs to a file, add --log-file-path:

bundle exec process_bot --command start --log true --log-file-path /var/log/process_bot.log

Use process_bot:sidekiq:graceful to wait for running jobs, and process_bot:sidekiq:graceful_no_wait to return immediately while Sidekiq drains.

You can restart Sidekiq while the old process drains by enabling overlap on the ProcessBot instance:

set :sidekiq_restart_overlap, true

When enabled, process_bot:sidekiq:restart will use the overlap behavior.

Or when running ProcessBot directly:

bundle exec process_bot --command restart --sidekiq-restart-overlap true

ProcessBot logging is enabled by default in the Capistrano integration. You can override it with:

set :process_bot_log, false

When running ProcessBot directly, you can control graceful waiting and log file output:

bundle exec process_bot --command graceful_no_wait
bundle exec process_bot --command start --log-file-path /var/log/process_bot.log

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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 bump the patch version, run bundle, commit the version bump, build, and push the gem, run bundle exec rake release:patch. 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 the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/kaspernj/process_bot.

The gem is available as open source under the terms of the MIT License.