未找到主连接池

Question

我正在使用 Rails，并且非常随机地遇到连接池错误，它没有专门针对任何单个端点。我可以在大约 70% 的时间内命中端点而不会收到此错误。该数据库是在Google Cloud上运行的PostgreSQL。这是我得到的错误的主要内容：

#<ActiveRecord::ConnectionNotEstablished: ActiveRecord::ConnectionNotEstablished>
/usr/local/bundle/gems/activerecord-5.1.5/lib/active_record/connection_handling.rb:112:in `connection_pool'
ActiveRecord::ConnectionNotEstablished (No connection pool with 'primary' found.):

宝石文件：

source 'https://rubygems.org'
git_source(:github) do |repo_name|
repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
"https://github.com/#{repo_name}.git"
end

gem 'rails', '~> 5.1.5'
gem 'pg', '>= 0.18', '< 2.0'
gem 'puma', '~> 3.7'
gem 'bcrypt', '~> 3.1.7'
gem 'jwt', '~> 1.5'
gem 'simple_command', '~> 0.0.9'
gem 'swagger-blocks', '~> 2.0.2'
gem 'active_model_serializers', '~> 0.10.2'
gem 'kaminari'
gem 'google-cloud-storage', '~> 1.10.0'
gem 'mini_magick', '~> 4.8.0'
gem 'carrierwave', '~> 1.2.0'
gem 'fog-google', '~> 1.3.0'
gem 'geocoder', '~> 1.4.7'
gem 'paper_trail', '~> 9.2.0'
gem 'paper_trail-association_tracking'
gem 'full-name-splitter', '~> 0.1.2'
gem 'pg_search'
gem 'mailgun-ruby', '~>1.1.6'

gem 'rack-cors'
group :development, :test, :staging, :dev do
gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
gem 'rspec-rails', '~> 3.7'
gem 'factory_bot_rails'
gem 'dotenv-rails'
gem 'pry-rails'
gem 'stackprof'
gem 'flamegraph'
gem 'rack-mini-profiler'
gem 'bullet'
gem 'seed_dump'
end
group :development do
gem 'listen', '>= 3.0.5', '< 3.2'
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
end
gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
gem 'devise', '~> 4.4.3'
gem 'activeadmin', github: 'activeadmin'
gem 'inherited_resources', git: 'https://github.com/activeadmin/inherited_resources'

Database.yml：

default: &default
adapter: postgresql
encoding: unicode
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
development:
<<: *default
database: rails_development
dev:
<<: *default
database: <%= ENV['DB_NAME'] %>
username: <%= ENV['DB_USER'] %>
password: <%= ENV['DB_PASSWORD'] %>
host: <%= ENV['DB_HOST'] %>
test:
<<: *default
database: rails_test
production:
<<: *default
database: <%= ENV['DB_NAME'] %>
username: <%= ENV['DB_USER'] %>
password: <%= ENV['DB_PASSWORD'] %>
host: <%= ENV['DB_HOST'] %>
staging:
<<: *default
database: <%= ENV['DB_NAME'] %>
username: <%= ENV['DB_USER'] %>
password: <%= ENV['DB_PASSWORD'] %>
host: <%= ENV['DB_HOST'] %>

我们正在使用：

红宝石 2.5.0 导轨 5.1.5

在Googles CloudSQL上使用Postgresql

Answer 1

首先：

$ gem uninstall sqlite

然后在 gemfile 中将其更改为：

gem 'sqlite3', '~> 1.3.6' 

和：

$ bundle install 
$ rake db:migrate

并重新启动服务器。 应该工作:)