[SOLVED] Is there an easy way to run Garbage Collection outside of the request cycle in Passenger?

Is there an easy way to run Garbage Collection outside of the request cycle in Passenger?

Unicorn has OobGC rack middleware that can be used to run GC.start after a certain number of requests.

Is there a similar sort of thing in Phusion Passenger?

Solution

Hooking into PhusionPassenger::Rack::RequestHandler#process_request() is the only mechanism I have found.

To do this in a similar way to the Unicorn OobGC, you can use the following module:

module PassengerOobGC
  def self.install!(path, interval = 5)
    self.const_set :OOBGC_PATH,     path
    self.const_set :OOBGC_INTERVAL, interval
    @@oob_nr = interval
    PhusionPassenger::Rack::RequestHandler.send :include, self
  end

  def self.included(base)
    base.send :alias_method_chain, :process_request, :gc
  end

  def process_request_with_gc(env, *args)
    process_request_without_gc(env, *args)

    if OOBGC_PATH =~ env["PATH_INFO"] && ((@@oob_nr -= 1) <= 0)
      @@oob_nr = OOBGC_INTERVAL
      GC.start
    end
  end
end

and invoke it in an initializer with:

if defined?(PhusionPassenger::Rack::RequestHandler)
  require 'passenger_oob_gc'
  PassengerOobGC.install!(%r{^/admin/}, 3)
end