How to disable HTTP/2 for my elixir app

As part of testing the migration of our Elixir/Phoenix app from Heroku to Render, we noticed that the same Elixir app that is currently hosted on Heroku needed way less DB connection pool, POOL_SIZE=5 ( which end up usually around ~ 20 for staging) but when we migrated to Render the app seems to keep dropping connections up until we set the POOL_SIZE=70, which can cause the DB concurrent connections to spike over 300.

My co-worker and I suspect this may be due to Heroku is on HTTP/1 vs. Render is HTTP/2, and I found below article, and our site also serves a lot of charts as contents which tend to cause multiple API calls on a single page load to gather chart needed plot data.

My question is, is there a way for me to disable HTTP/2 service on Render? and only serve to HTTP/1.1 and HTTP/1.2?

Hi foobar_e,

Unfortunately disabling HTTP/2 won’t be possible for services hosted on Render. Is POOL_SIZE=70 the lowest number that you are able use where connections aren’t dropped?

Yes correct - even at POOL_SIZE=70 it seems the app drops connection at times, for production test I updated it to 80

So in this case, what would you recommend as some alternative methods to limit the concurrent client connections and serve them in sequential orders?