grpc_fork_safety

GrpcForkSafety

Small gem that makes it easier to use the grpc gem in a fork safe way.

Installation

Add the gem to your gemfile **before the grpc gem, or any gem that depend on grpc:

gem "grpc_fork_safety"
gem "grpc"
gem "some-gem-that-depend-on-grpc"

Usage

There isn't anything particular to do, the gem will hook itself into Ruby and properly call the GRPC fork hooks when needed.

keep_disabled!

However, when a process will need to fork repeatedly and won't need to use GRPC, you can optimize by calling GrpcForkSafety.keep_disabled!. grpc will be enabled again in child process, but stay shutdown in the current process. This is useful for the main process of Puma or Unicorn and for the mold process of Pitchfork, e.g.

before_fork do
  GrpcForkSafety.keep_disabled!
end

If for some reason you need to undo this, you can call GrpcForkSafety.reenable!

Hooks

You can also register hooks to be called before GRPC is disabled and after it's re-enabled:

GrpcForkSafety.before_disable do
  ThreadPool.shutdown
end

GrpcForkSafety.after_enable do |in_child|
  unless in_child
    ThreadPool.start
  end
end

Typically if you have background threads using GRPC, you should make sure to shut them down in before_disable.

Development

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 the created tag, and push the .gem file to rubygems.org.

Contributing

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