How to mix 2X and PX dynodes for web process in Heroku?

Question

I want to use both 2X and PX dynodes for my web application. Therefore, in my Procfile, I have the following configuration:

web: env WEB_CONCURRENCY=4 bundle exec unicorn -p $PORT -c ./config/unicorn.rb
web_px: env WEB_CONCURRENCY=20 bundle exec unicorn -p $PORT -c ./config/unicorn.rb

But, based on Heroku's metric, it seems that only one is webused to process the web request ( web_pxone is not used most of the time).

How can I say that Heroku uses both web, and web_pxto process an HTTP request?

Answer 1

Here is the answer from Heroku technical support:

Hi,

dynos named web. . , .