Allow configurable concurrency setting.

[andychongyz]

Hi people, I realize the gem automatically turns on the concurrency feature by default on production. And we have been suffered from the ActiveRecord Connection Pool issue until we monkey-patched the establish_concurrency method. What if we allow setting that in the configure block. I also realized that concurrency does not benefits smaller app running on a single core server like the Heroku Standard-1X instance.

Here's a small snapshot of before and after (the small rocket icon indicates the deployment to turn off concurrency):

[richmolj]

Yup it's already there - config.concurrency = false

[andychongyz]

But, that doesn't work for me. I have the configuration file in the /initializers dir in my rails app. But the establish_concurrency method executes after the configuration code is executed, which overwrite the configuration. Could it be because I'm on Ruby 3 🤔 .
I ended up monkey-patched the code like below:

::Graphiti::Rails::Railtie.class_eval do
  def establish_concurrency
    Graphiti.config.concurrency = false
  end
end