Return-Path: X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by cust-asf2.ponee.io (Postfix) with ESMTP id A0FFD200BB0 for ; Sun, 16 Oct 2016 05:45:27 +0200 (CEST) Received: by cust-asf.ponee.io (Postfix) id 9F82E160AF4; Sun, 16 Oct 2016 03:45:27 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id BCC12160AF1 for ; Sun, 16 Oct 2016 05:45:26 +0200 (CEST) Received: (qmail 3154 invoked by uid 500); 16 Oct 2016 03:45:25 -0000 Mailing-List: contact user-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@accumulo.apache.org Delivered-To: mailing list user@accumulo.apache.org Received: (qmail 3144 invoked by uid 99); 16 Oct 2016 03:45:25 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 16 Oct 2016 03:45:25 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id D3D91C02A0 for ; Sun, 16 Oct 2016 03:45:24 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 3.629 X-Spam-Level: *** X-Spam-Status: No, score=3.629 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_REPLY=1, HTML_MESSAGE=2, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_SORBS_SPAM=0.5, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd1-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id b9FQ6xTxNlXY for ; Sun, 16 Oct 2016 03:45:22 +0000 (UTC) Received: from mail-wm0-f54.google.com (mail-wm0-f54.google.com [74.125.82.54]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTPS id D9F995FAD5 for ; Sun, 16 Oct 2016 03:45:21 +0000 (UTC) Received: by mail-wm0-f54.google.com with SMTP id f193so50527249wmg.1 for ; Sat, 15 Oct 2016 20:45:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=4sKePe/uub+Nbgho60WIiYGi4OpkHozXHCNX3eVqGTs=; b=RNb0pXSqUxRXsM3OtWYCYz07m+TxWSVEWwomUB4vrWphR0GV01FPJmrKryjfcM3yXf uexljTSmuqNzgtPtOYxW9av08+LDjNwxlaleyXv3m76D1wqiYynIFt0Wx2xeujRMGcsD WFczatNPJe7cYn/8X4xXLY9KYp8hGv3VbP4hM4G7wkUgUX03PE589tkS9MGBI1wvxdWx FVLxR0TDpBW8QI1oq0Q6RL85TwSx7mvZqgqf0FNxN+bu6fSJu6Ql+BbgXMb9jfdxfe32 2QwSRbcg8oRyvSmLUsLnKbmcJXbGzPGxYeZhB7AHsnxglGgz/KmIfeFyll85/T3WMHYP IJxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=4sKePe/uub+Nbgho60WIiYGi4OpkHozXHCNX3eVqGTs=; b=YP8Z9U+lH18Vml3Yuq4ta8c+sYBH7OXiSiCxG8tutQkZaLC9MRvi0aZnxyVQmIFQrm Wti5+VZLSw30DerGqF248etC7WKSeIFjsCIiN1xsakXpzJ20F0LLWvHoLFdPdxCgpOty Jw0KSfxSqmOHkhq3wljl1+RtYqFnyTJFDGAzrQY8OaMKe8SW6qgw6xvkI5Q8NFK4MeTi 163umBAsQTso5BTFn91GPKDaKd4CwFLzqsTCDiRI+LLps2t4KOD+0QuqhOzhyt+uxKmg E3uuheQnccpV3HNFPwf/2A76VMs7qk4vK/Mn5XA3RYhS2FGmJM2NYk9GD6ceFkY1g/+1 RXtg== X-Gm-Message-State: AA6/9RnLXVLLu1tIGzZvAECkI2li97J6o4ZRf7ZGv9QQ5WY9Qxvnt3nTOj2Io0F6kcOKjEHTNwDp3EVQNtX3iw== X-Received: by 10.28.232.23 with SMTP id f23mr3990231wmh.125.1476589520484; Sat, 15 Oct 2016 20:45:20 -0700 (PDT) MIME-Version: 1.0 Received: by 10.28.178.194 with HTTP; Sat, 15 Oct 2016 20:44:40 -0700 (PDT) In-Reply-To: <57FFBA5F.5070100@gmail.com> References: <57FFB0EE.3050000@gmail.com> <57FFBA5F.5070100@gmail.com> From: Yamini Joshi Date: Sat, 15 Oct 2016 22:44:40 -0500 Message-ID: Subject: Re: Data Replication To: user@accumulo.apache.org Content-Type: multipart/alternative; boundary=001a11466da2d8ff85053ef34975 archived-at: Sun, 16 Oct 2016 03:45:27 -0000 --001a11466da2d8ff85053ef34975 Content-Type: text/plain; charset=UTF-8 So HDFS is for durability while replication is for availability? I'm assuming that the client is unaware of the replicated instance and queries the DB with no knowledge of which instance/table will return the result. Best regards, Yamini Joshi On Thu, Oct 13, 2016 at 11:46 AM, Josh Elser wrote: > I'm not familiar with MongoDB. Perhaps someone else can confirm this for > you. > > Yamini Joshi wrote: > >> So, can I say that if I have a table split across nodes (i.e. num >> tablets > 1) and HDFS replication in my system, it is sort of equivalent >> to a sharded and replicated mongo architecture? >> >> Best regards, >> Yamini Joshi >> >> On Thu, Oct 13, 2016 at 11:06 AM, Josh Elser > > wrote: >> >> The Accumulo (Data Center) Replication feature is for having >> multiple active Accumulo clusters all containing the same data. >> >> HDFS provides replication as a means for durability of the data it >> is storing. The files that Accumulo creates on one HDFS instance are >> replicated by HDFS. This does not help if your entire cluster become >> unavailable. That is what the data center replication Accumulo >> feature solves. >> >> While both can be called "replication", they serve very different >> purposes. >> >> >> Yamini Joshi wrote: >> >> Hello >> >> I was going through some Accumulo docs and found out about >> replication. >> To enable replication,one needs to make some config settings as >> described in >> https://github.com/apache/accumulo/blob/master/docs/src/main >> /asciidoc/chapters/replication.txt >> > n/asciidoc/chapters/replication.txt>. >> I cannot seem to grasp the difference between this replication >> conf and >> the replication on HDFS level. What exactly is the use case for >> replication? Are the replicated instances visible to the clients? >> >> Best regards, >> Yamini Joshi >> >> >> --001a11466da2d8ff85053ef34975 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
So HDFS is for durability while replication is for availab= ility? I'm assuming that the client is unaware of the replicated instan= ce and queries the DB with no knowledge of which instance/table will return= the result.

Best regards,
Yamini Joshi

On Thu, Oct 13, 2016 at 11:46 AM, Josh Elser= <josh.elser@gmail.com> wrote:
I'm not familiar with MongoDB. Perhaps someone else can confirm= this for you.

Yamini Joshi wrote:
So, can I say that if I have a table split across nodes (i.e. num
tablets > 1) and HDFS replication in my system, it is sort of equivalent=
to a sharded and replicated mongo architecture?

Best regards,
Yamini Joshi

On Thu, Oct 13, 2016 at 11:06 AM, Josh Elser <josh.elser@gmail.com
 <mailto:josh.e= lser@gmail.com>> wrote:

=C2=A0 =C2=A0 The Accumulo (Data Center) Replication feature is for having<= br> =C2=A0 =C2=A0 multiple active Accumulo clusters all containing the same dat= a.

=C2=A0 =C2=A0 HDFS provides replication as a means for durability of the da= ta it
=C2=A0 =C2=A0 is storing. The files that Accumulo creates on one HDFS insta= nce are
=C2=A0 =C2=A0 replicated by HDFS. This does not help if your entire cluster= become
=C2=A0 =C2=A0 unavailable. That is what the data center replication Accumul= o
=C2=A0 =C2=A0 feature solves.

=C2=A0 =C2=A0 While both can be called "replication", they serve = very different
=C2=A0 =C2=A0 purposes.


=C2=A0 =C2=A0 Yamini Joshi wrote:

=C2=A0 =C2=A0 =C2=A0 =C2=A0 Hello

=C2=A0 =C2=A0 =C2=A0 =C2=A0 I was going through some Accumulo docs and foun= d out about
=C2=A0 =C2=A0 =C2=A0 =C2=A0 replication.
=C2=A0 =C2=A0 =C2=A0 =C2=A0 To enable replication,one needs to make some co= nfig settings as
=C2=A0 =C2=A0 =C2=A0 =C2=A0 described in
=C2=A0 =C2=A0 =C2=A0 =C2=A0 https://github.com/apache/accumulo/blob/master/d= ocs/src/main/asciidoc/chapters/replication.txt
 =C2=A0 =C2=A0 =C2=A0 =C2=A0 <https://github.com/apache/accumulo/blob/mast= er/docs/src/main/asciidoc/chapters/replication.txt>.
=C2=A0 =C2=A0 =C2=A0 =C2=A0 I cannot seem to grasp the difference between t= his replication
=C2=A0 =C2=A0 =C2=A0 =C2=A0 conf and
=C2=A0 =C2=A0 =C2=A0 =C2=A0 the replication on HDFS level. What exactly is = the use case for
=C2=A0 =C2=A0 =C2=A0 =C2=A0 replication? Are the replicated instances visib= le to the clients?

=C2=A0 =C2=A0 =C2=A0 =C2=A0 Best regards,
=C2=A0 =C2=A0 =C2=A0 =C2=A0 Yamini Joshi



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