State servers

gmosx answered:

The state server is useful to store distributed sessions and distributed global variables. First of all you need to define your state server using the special file state.rb in your main directory. Here is an example:

#!/usr/bin/env ruby

$LOAD_PATH.unshift 'lib'

require 'nitro/server/drb'
require 'nitro/session/drb'
require 'nitro/global'

Nitro::Session.cache_port = 9050
Global.cache_port = 9051

# DrbServer 

class AppDrbServer < Nitro::DrbServer
  def setup_drb_objects
    super
     
    @global_cache = SyncHash.new 
    DRb.start_service("druby://#{Global.cache_address}:#{Global.cache_port}", @global_cac
he)    
    puts "Drb global cache at druby://#{Global.cache_address}:#{Global.cache_port}."  
  end
end    

AppDrbServer.start

The nitro command automatically starts the state server if needed. Here is an example invocation:

nitro --live --mongrel --cluster 3

This commands starts 3 application server as a mongrel cluster listening on ports baseport, baseport 1, baseport 2 and one state server.

nitro stop

stops the application servers but not the state server, useful for restarts that the users don't notice.

nitro kill

stops the application servers and the state server.