Return-Path: X-Original-To: apmail-hadoop-common-user-archive@www.apache.org Delivered-To: apmail-hadoop-common-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 1FD5C90DB for ; Wed, 21 Mar 2012 22:16:05 +0000 (UTC) Received: (qmail 73096 invoked by uid 500); 21 Mar 2012 22:16:01 -0000 Delivered-To: apmail-hadoop-common-user-archive@hadoop.apache.org Received: (qmail 73023 invoked by uid 500); 21 Mar 2012 22:16:01 -0000 Mailing-List: contact common-user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: common-user@hadoop.apache.org Delivered-To: mailing list common-user@hadoop.apache.org Received: (qmail 73015 invoked by uid 99); 21 Mar 2012 22:16:01 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 21 Mar 2012 22:16:01 +0000 X-ASF-Spam-Status: No, hits=-5.0 required=5.0 tests=RCVD_IN_DNSWL_HI,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of Milind.Bhandarkar@emc.com designates 128.222.32.20 as permitted sender) Received: from [128.222.32.20] (HELO mexforward.lss.emc.com) (128.222.32.20) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 21 Mar 2012 22:15:53 +0000 Received: from hop04-l1d11-si04.isus.emc.com (HOP04-L1D11-SI04.isus.emc.com [10.254.111.24]) by mexforward.lss.emc.com (Switch-3.4.3/Switch-3.4.3) with ESMTP id q2LMFUKH031313 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 21 Mar 2012 18:15:31 -0400 Received: from mailhub.lss.emc.com (mailhubhoprd02.lss.emc.com [10.254.221.253]) by hop04-l1d11-si04.isus.emc.com (RSA Interceptor) for ; Wed, 21 Mar 2012 18:15:20 -0400 Received: from mxhub36.corp.emc.com (mxhub36.corp.emc.com [10.254.93.84]) by mailhub.lss.emc.com (Switch-3.4.3/Switch-3.4.3) with ESMTP id q2LMFKBQ002723 for ; Wed, 21 Mar 2012 18:15:20 -0400 Received: from mx21a.corp.emc.com ([169.254.1.36]) by mxhub36.corp.emc.com ([::1]) with mapi; Wed, 21 Mar 2012 18:15:20 -0400 From: To: Date: Wed, 21 Mar 2012 18:14:13 -0400 Subject: Re: Very strange Java Collection behavior in Hadoop Thread-Topic: Very strange Java Collection behavior in Hadoop Thread-Index: Ac0HsBm6o7q31XPLTCKRs7T9tbwpSg== Message-ID: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Microsoft-MacOutlook/14.14.0.111121 acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-EMM-MHVC: 1 X-Virus-Checked: Checked by ClamAV on apache.org Owen, Is there interest in reverting hadoop-2399 in 0.23.x ? - Milind --- Milind Bhandarkar Greenplum Labs, EMC (Disclaimer: Opinions expressed in this email are those of the author, and do not necessarily represent the views of any organization, past or present, the author might be affiliated with.) On 3/19/12 11:20 PM, "Owen O'Malley" wrote: >On Mon, Mar 19, 2012 at 11:05 PM, madhu phatak >wrote: > >> Hi Owen O'Malley, >> Thank you for that Instant reply. It's working now. Can you explain me >> what you mean by "input to reducer is reused" in little detail? > > >Each time the statement "Text value =3D values.next();" is executed it >always >returns the same Text object with the contents of that object changed. >When >you add the Text to the list, you are adding a pointer to the same Text >object. At the end you have 6 copies of the same pointer instead of 6 >different Text objects. > >The reason that I said it is my fault, is because I added the optimization >that causes it. If you are interested in Hadoop archeology, it was >HADOOP-2399 that made the change. I also did HADOOP-3522 to improve the >documentation in the area. > >-- Owen