hadoop源码2.2.0ApacheHadoop2.2.0istheGAreleaseofApacheHadoop2.x.Usersareencouragedtoimmediatelymoveto2.2.0sincethisreleaseissignificantlymorestableandisguaranteedtoremaincompatibleintermsofbothAPIsandprotocols.Torecap,thisreleasehasanumberofsignificant