gistfile1.txt

require 'active_record'

config = <<~CONF
  development:
    adapter: sqlite3
    database: ":memory:"
    host_names:
      - test.localhost
CONF

ActiveRecord::Base.configurations = ActiveRecord::DatabaseConfigurations.new(YAML::load(config))
ActiveRecord::Base.establish_connection(:development)

(0..4).map do |thread_number|
  Thread.new do
    # Obtain a reference to the schema cache, and log which connection it's using
    my_schema_cache = ActiveRecord::Base.connection.schema_cache
    initial_conn_id = my_schema_cache.connection.object_id

    # Do something else
    sleep 1 

    # Now check the schema cache connection again
    final_conn_id = my_schema_cache.connection.object_id
    if initial_conn_id != final_conn_id
      puts "Thread #{thread_number} switched connection from #{initial_conn_id} to #{final_conn_id}"  
    end
  end
end.each(&:join)