array=[["CAMP11WDP", {"host"=>"cambrai","port"=>"50001"}], ["CAMP12WDP", {"host"=>"cambrai","port"=>"50002"}], ["VILP11WDP", {"host"=>"villeneuve","port"=>"50001"}], ["VILP12WDP", {"host"=>"villeneuve","port"=>"50002"}], ["CHAP11WDP", {"host"=>"chat","port"=>"50001"}], ["CHAP12WDP", {"host"=>"chat","port"=>"50002"}]]

array_host=[] array.each { |instances,values| unless array_host.include?(values["host"]) array_host << values["host"] puts instances puts values end }