Return-Path: X-Original-To: apmail-hadoop-hdfs-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-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 4B93B9A92 for ; Fri, 28 Dec 2012 22:20:17 +0000 (UTC) Received: (qmail 61854 invoked by uid 500); 28 Dec 2012 22:20:12 -0000 Delivered-To: apmail-hadoop-hdfs-user-archive@hadoop.apache.org Received: (qmail 61767 invoked by uid 500); 28 Dec 2012 22:20:11 -0000 Mailing-List: contact user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hadoop.apache.org Delivered-To: mailing list user@hadoop.apache.org Received: (qmail 61760 invoked by uid 99); 28 Dec 2012 22:20:11 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 28 Dec 2012 22:20:11 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of michael_segel@hotmail.com designates 65.55.111.86 as permitted sender) Received: from [65.55.111.86] (HELO blu0-omc2-s11.blu0.hotmail.com) (65.55.111.86) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 28 Dec 2012 22:20:04 +0000 Received: from BLU0-SMTP447 ([65.55.111.71]) by blu0-omc2-s11.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Fri, 28 Dec 2012 14:19:43 -0800 X-EIP: [rArbvXtHX3UIH3cIARwLd2M34wY+jbjy] X-Originating-Email: [michael_segel@hotmail.com] Message-ID: Received: from [192.168.0.106] ([173.15.87.37]) by BLU0-SMTP447.blu0.hotmail.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Fri, 28 Dec 2012 14:19:41 -0800 References: MIME-Version: 1.0 (1.0) In-Reply-To: Content-Type: multipart/alternative; boundary="Apple-Mail-F4A5F68D-F662-45C5-8030-3DF2CD70CF50" Content-Transfer-Encoding: 7bit CC: "common-user@hadoop.apache.org" X-Mailer: iPad Mail (10A523) From: Michel Segel Subject: Re: What is the preferred way to pass a small number of configuration parameters to a mapper or reducer Date: Fri, 28 Dec 2012 16:19:39 -0600 To: "user@hadoop.apache.org" X-OriginalArrivalTime: 28 Dec 2012 22:19:41.0866 (UTC) FILETIME=[6ED860A0:01CDE549] X-Virus-Checked: Checked by ClamAV on apache.org --Apple-Mail-F4A5F68D-F662-45C5-8030-3DF2CD70CF50 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Sounds like someone is cheating on a test... Sent from a remote device. Please excuse any typos... Mike Segel On Dec 28, 2012, at 3:10 PM, Ted Dunning wrote: > Answer B sounds pathologically bad to me. >=20 > A or C are the only viable options. >=20 > Neither B nor D work. B fails because it would be extremely hard to get t= he right records to the right components and because it pollutes data input w= ith configuration data. D fails because statics don't work in parallel prog= rams. >=20 >=20 > On Fri, Dec 28, 2012 at 12:17 AM, Kshiva Kps wrote: >>=20 >> Which one is current .. >>=20 >> What is the preferred way to pass a small number of configuration paramet= ers to a mapper or reducer? >> =20 >> =20 >> A. As key-value pairs in the jobconf object. >> =20 >> B. As a custom input key-value pair passed to each mapper or reducer. >> =20 >> C. Using a plain text file via the Distributedcache, which each mapper o= r reducer reads. >> =20 >> D. Through a static variable in the MapReduce driver class (i.e., the cl= ass that submits the MapReduce job). >> =20 >> Answer: B >=20 --Apple-Mail-F4A5F68D-F662-45C5-8030-3DF2CD70CF50 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: 7bit
Sounds like someone is cheating on a test...

Sent from a remote device. Please excuse any typos...

Mike Segel

On Dec 28, 2012, at 3:10 PM, Ted Dunning <tdunning@maprtech.com> wrote:

Answer B sounds pathologically bad to me.

A or C are the only viable options.

Neither B nor D work.  B fails because it would be extremely hard to get the right records to the right components and because it pollutes data input with configuration data.  D fails because statics don't work in parallel programs.


On Fri, Dec 28, 2012 at 12:17 AM, Kshiva Kps <kshivakps@gmail.com> wrote:


Which one is current ..


What is the preferred way to pass a small number of configuration parameters to a mapper or reducer?

 

 

A.  As key-value pairs in the jobconf object.

 

B.  As a custom input key-value pair passed to each mapper or reducer.

 

C.  Using a plain text file via the Distributedcache, which each mapper or reducer reads.

 

D.  Through a static variable in the MapReduce driver class (i.e., the class that submits the MapReduce job).

 

Answer: B

 


--Apple-Mail-F4A5F68D-F662-45C5-8030-3DF2CD70CF50--