Every frequency seconds, the reaper will call reap on pool. A reaper instantiated with a nil frequency will never reap the connection pool.

Configure the frequency by setting “reaping_frequency” in your database yaml file.

Methods
N
R
Attributes
[R] frequency
[R] pool
Class Public methods
new(pool, frequency)

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 206
def initialize(pool, frequency)
  @pool      = pool
  @frequency = frequency
end
Instance Public methods
run()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 211
def run
  return unless frequency
  Thread.new(frequency, pool) { |t, p|
    while true
      sleep t
      p.reap
    end
  }
end