Puma & Sqlite3 - ActiveRecord::ConnectionTimeoutError

[anusharanganathan]

could not obtain a connection from the pool within 5.000 seconds (waited 5.000 seconds); all pooled connections were in use

This error appears on startup. Started in the new year.

puma-activerecorderror.pdf

[anusharanganathan]

To bypass this error, I have stopped using puma for development. commit acf7751f2068a9bf0ea8417f073c816a66a278e2

1. Stop puma

   sudo systemctl stop puma.socket

2. Modify Gemfile to use puma only for production

   group :production do
     # Use Puma as the app server
     gem 'puma', '~> 3.7'
   end

3. Bundle install only development gems

   bundle install --without production

   Reference: https://stackoverflow.com/questions/36647206/prevent-puma-from-running-in-locally-ruby-on-rails

4. Run rails server in screen

   cd ~/data2paper
   screen -r
   bundle exec rails s -b 127.0.0.1

5. Create a new site data2paper-3000 in nginx and use that instead of the current data2paper site

   sudo rm /etc/nginx/sites-enabled/data2paper
   sudo cp docs/data2paper-3000 sudo cp /etc/nginx/sites-available/data2paper /etc/nginx/sites-available/
   sudo ln -s /etc/nginx/sites-available/data2paper-3000 /etc/nginx/sites-enabled/data2paper-3000
   sudo systemctl restart nginx

[anusharanganathan]

I get the same error with postgres too 🙍

[martyn-w]

My suspicion is that this is some artefact of a single-threaded process (such as SQLite), or possibly a database pool configuration issue. I have not observed this error when running Puma and Postgres in the dockerised branch (refactor)