Heroku “connection limit exceeded for non-superusers”

Question

I am using free Heroku plan with shared database. Cedar stack, Rails 3.1.0.rc4.

When launching the application I constantly get this error, which breaks the process and which sometimes disappears after a random push:

2011-07-21T08:36:17+00:00 heroku[web.1]: Starting process with command: bundle exec rails server -p 11382 thin 2011-07-21T08:36:23+00:00 app[web.1]: => Booting Thin 2011-07-21T08:36:23+00:00 app[web.1]: => Rails 3.1.0.rc4 application starting in production on http://0.0.0.0:11382 2011-07-21T08:36:23+00:00 app[web.1]: => Call with -d to detach 2011-07-21T08:36:23+00:00 app[web.1]: => Ctrl-C to shutdown server 2011-07-21T08:36:23+00:00 app[web.1]: Exiting 2011-07-21T08:36:23+00:00 app[web.1]: /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/postgresql_adapter.rb:987:in initialize': FATAL: connection limit exceeded for non-superusers (PGError) 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/postgresql_adapter.rb:987:in new' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/postgresql_adapter.rb:987:in connect' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/postgresql_adapter.rb:260:in initialize' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/postgresql_adapter.rb:27:in new' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/postgresql_adapter.rb:27:in postgresql_connection' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in new_connection' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:302:in checkout_new_connection' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:254:in block (2 levels) in checkout' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:250:in loop' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:250:in block in checkout' 2011-07-21T08:36:23+00:00 app[web.1]: from /usr/local/lib/ruby/1.9.1/monitor.rb:201:inmon_synchronize' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:249:in checkout' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:151:in con

2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_pool.rb:388:in retrieve_connection' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_specification.rb:107:in retrieve_connection' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/connection_adapters/abstract/connection_specification.rb:89:in connection' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/base.rb:704:in table_exists?' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.1.0.rc4/lib/active_record/base.rb:789:in attribute_names' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.1.0.rc4/lib/action_controller/metal/params_wrapper.rb:169:in _set_wrapper_defaults' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.1.0.rc4/lib/action_controller/metal/params_wrapper.rb:129:in inherited' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.1.0.rc4/lib/abstract_controller/railties/routes_helpers.rb:7:in block (2 levels) in with' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.1.0.rc4/lib/action_controller/railties/paths.rb:7:in block (2 levels) in with' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/app/controllers/customers_controller.rb:1:in' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:237:in require' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:237:in block in require' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:225:in load_dependency' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:237:in require' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:344:in require_or_load' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:298:in depend_on' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:214:in require_dependency' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/engine.rb:399:in block (2 levels) in eager_load!' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/engine.rb:398:in each' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/engine.rb:398:in block in eager_load!' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/engine.rb:396:in each' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/engine.rb:396:in eager_load!' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/application.rb:83:in eager_load!' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/application/finisher.rb:51:in block in ' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/initializable.rb:25:in instance_exec' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/initializable.rb:25:in run' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/initializable.rb:50:in block in run_initializers' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/initializable.rb:49:in each' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/initializable.rb:49:in run_initializers' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/application.rb:96:in initialize!' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc4/lib/rails/railtie/configurable.rb:30:in method_missing' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/config/environment.rb:5:in' 2011-07-21T08:36:23+00:00 app[web.1]: from /app/config.ru:4:in `block in ' 2011-07-21T08:36:23+00:00 heroku[web.1]: Process exited 2011-07-21T08:36:24+00:00 heroku[web.1]: State changed from starting to crashed 2011-07-21T08:36:24+00:00 heroku[router]: Error H10 (App crashed) -> GET dyno= queue= wait= service= status=503 bytes= 2011-07-21T08:36:25+00:00 heroku[router]: Error H10

I don't see any piece of my own code in this message.

Answer 1

That's a Postgresql error messsage that you get when you have more connections than specified in the max_connections setting in postgresql.conf. Unless you can change that yourself, you'll probably have to contact Heroku support.