When I require the "grape/activerecord/rake" file the app wont start anymore. This is the error:

.../gems/activerecord-4.2.3/lib/active_record/railties/databases.rake:3:in `<top (required)>': undefined method `namespace' for main:Object (NoMethodError)

Rake tasks do actually work, so could use them by just only enabling the lines when I need migration tasks, but its nicer if I can always have the tasks available.

Note to self: Fix by using app.after_validation, app.after, and app.rescue_from :all.

Our project uses ENVied to refer to database host, username, etc. in the config/database.yml file, so we need to have loaded ENVied before loading active_record and connecting to the database. This project's README suggests putting such application loading in a rake task db:environment. This would load fine if our database config was located somewhere else, but since it's in config/database.yml your defaults.rb file calls database_file= before this environment task is executed, which fails because ENVied hasn't loaded yet.

It would be preferable if grape-activerecord didn't set the database file until the end of the database environment task, so that if any setup is required in order for activerecord to use the database file it can be performed there.

ActiveRecord config loader:

Grape::ActiveRecord.database_file = File.join(__dir__, '..', 'config', 'database.yml')

database.yml:

development:
  adapter: postgresql
  host: 192.168.7.16
  encoding: unicode
  username: postgres
  password: secret
  database: app_development
  pool: 10

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  adapter: postgresql
  host: 192.168.7.16
  encoding: unicode
  username: postgres
  password: secret
  database: app_test
  pool: 10

production:
  adapter: postgresql
  host: 192.168.7.16
  encoding: unicode
  username: postgres
  password: secret
  database: app_production
  pool: 10

Then when I test it with:

ab -c 10 -n 1000 http://192.168.7.10/users

It opens exactly 20 connections to PostgreSQL:

tcp        0    139 192.168.7.16:postgresql 192.168.7.10:39666    ESTABLISHED
tcp        0      0 192.168.7.16:postgresql 192.168.7.10:39658    ESTABLISHED
tcp        0      0 192.168.7.16:postgresql 192.168.7.10:39664    ESTABLISHED
tcp        0      0 192.168.7.16:postgresql 192.168.7.10:39662    ESTABLISHED
...

The same if I make pool: 2 or pool: 70.

Hi, Thanks for writing this gem. I've come across this issue:

Using grape-activerecord 0.0.8
Using activerecord 4.2.3

When I follow the README and include Grape::ActiveRecord::Extension in my Grape API class I get the following error:

undefined method 'downcase' for 2:Fixnum

Ruby    /home/vagrant/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/utils.rb: in [], line 501

Looking into that code there are just these two lines:

Grape::ActiveRecord.setup!
app.use ::ActiveRecord::ConnectionAdapters::ConnectionManagement

When I remove the include Grape::ActiveRecord::Extension from the API class and replace it with just Grape::ActiveRecord.setup! it works fine.

Following your README I have put in config.ru use ActiveRecord::ConnectionAdapters::ConnectionManagement

I played around with removing the use from config.ru since it seems redundant when including the mixin, but that didn't remove the error. any idea?