Return-Path: X-Original-To: apmail-hadoop-mapreduce-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-mapreduce-user-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 7DB1D878B for ; Wed, 7 Sep 2011 08:01:13 +0000 (UTC) Received: (qmail 81530 invoked by uid 500); 7 Sep 2011 08:01:07 -0000 Delivered-To: apmail-hadoop-mapreduce-user-archive@hadoop.apache.org Received: (qmail 81047 invoked by uid 500); 7 Sep 2011 08:00:34 -0000 Mailing-List: contact mapreduce-user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: mapreduce-user@hadoop.apache.org Delivered-To: mailing list mapreduce-user@hadoop.apache.org Received: (qmail 80998 invoked by uid 99); 7 Sep 2011 08:00:31 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 07 Sep 2011 08:00:31 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of bejoy.hadoop@gmail.com designates 209.85.216.169 as permitted sender) Received: from [209.85.216.169] (HELO mail-qy0-f169.google.com) (209.85.216.169) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 07 Sep 2011 08:00:25 +0000 Received: by qyk27 with SMTP id 27so1219262qyk.14 for ; Wed, 07 Sep 2011 01:00:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=GZdOlnGzIy8b/2/CR2VD/SiR1kWH8pwhXxm1Iz6SHBM=; b=JNYylwZC3zI5pc4I47peiglPVc4Uz8Ouf2zq5CVxf5B56fMVbQ7wsBnZPMKEJXUQUg PIzGf7EIFfTdiDZoh1u9PBO3cY3LJ3MF567K60Ci/XdwNnDpIfRrc10C14V7DCo0NwZz 4/XElB+uWPwwMDCAHw+61LxY6tYrjLHK8sR7Y= MIME-Version: 1.0 Received: by 10.229.63.156 with SMTP id b28mr4807896qci.2.1315382402663; Wed, 07 Sep 2011 01:00:02 -0700 (PDT) Received: by 10.229.182.138 with HTTP; Wed, 7 Sep 2011 01:00:02 -0700 (PDT) In-Reply-To: References: Date: Wed, 7 Sep 2011 13:30:02 +0530 Message-ID: Subject: Re: No Mapper but Reducer From: Bejoy KS To: mapreduce-user@hadoop.apache.org Content-Type: multipart/alternative; boundary=0016e654fd68dac77204ac555418 X-Virus-Checked: Checked by ClamAV on apache.org --0016e654fd68dac77204ac555418 Content-Type: text/plain; charset=ISO-8859-1 Thanks Sonal. I was just thinking of some weird design and wanted to make sure whether there is a possibility like that- no maps and all reducers. On Wed, Sep 7, 2011 at 1:22 PM, Sonal Goyal wrote: > I dont think that is possible, can you explain in what scenario you want to > have no mappers, only reducers? > > Best Regards, > Sonal > Crux: Reporting for HBase > Nube Technologies > > > > > > > > > On Wed, Sep 7, 2011 at 1:18 PM, Bejoy KS wrote: > >> Hi >> I'm having a query here. Is it possible to have no mappers but >> reducers alone? AFAIK If we need to avoid the tyriggering of reducers we can >> set numReduceTasks to zero but such a setting on mapper wont work. So how >> can it be achieved if possible? >> >> Thank You >> >> Regards >> Bejoy.K.S >> > > --0016e654fd68dac77204ac555418 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Sonal. I was just thinking of some weird design and wanted to make s= ure whether there is a possibility like that- no maps and all reducers.
=
On Wed, Sep 7, 2011 at 1:22 PM, Sonal Goyal = <sonalgoyal4@= gmail.com> wrote:
I dont think that is possible,=A0can you ex= plain in what scenario you want to have no mappers, only reducers?=A0
<= br clear=3D"all"> Best Regards,
Sonal
Crux: Reporting for HBa= se
Nube Technologies

=






On Wed, Sep 7, 2011 at 1:18 PM, Bejoy KS= <bejoy.hadoop@gmail.com> wrote:
Hi
=A0=A0=A0=A0=A0=A0=A0=A0=A0 I'm having a query here. Is it possi= ble to have no mappers but reducers alone? AFAIK If we need to avoid the ty= riggering of reducers we can set numReduceTasks to zero but such a setting = on mapper wont work. So how can it be achieved if possible?

Thank You

Regards
Bejoy.K.S


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