Mailing-List: contact user-help@couchdb.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@couchdb.apache.org
Received-SPF: pass (athena.apache.org: domain of randall.leeds@gmail.com
 designates 209.85.161.52 as permitted sender)
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        b=GbBy3Iqv0HvXt4Gm4NU/V/vY4W+W9pMQHQARBszbJa6zqi8MS166u3MEHKOrrhay1h
         NUHo0S4+Q5UhAfIk4CUUPoz/R7Lp1L7az3COMEx5ZkTH+pUiESaTbpIipqcfKLD+Mb7h
         onJcOhhSDcKj9kiUk7Rgi70VulJ7VOAFxKriY=
MIME-Version: 1.0
In-Reply-To: <AANLkTim5OrCzgMZu4Qe7wqOxirJN9kubs1VFyFw3tD1t@mail.gmail.com>
References: <AANLkTim5OrCzgMZu4Qe7wqOxirJN9kubs1VFyFw3tD1t@mail.gmail.com>
Date: Mon, 20 Sep 2010 22:31:08 +0200
Message-ID: <AANLkTimSyr0kHcjCUwbQiDbch5d+CsDjCvL5g2Q1Vcrk@mail.gmail.com>
Subject: Re: distributed map-reduce views
From: Randall Leeds <randall.leeds@gmail.com>
To: user@couchdb.apache.org
Content-Type: text/plain; charset=UTF-8

On Sun, Sep 19, 2010 at 20:37, Christopher Bare
<cbare@systemsbiology.org> wrote:
> Hi Couch-potatoes,
>
> I'm investigating using CouchDB for a data mining application and
> could use some advice.

Cool! Welcome to the party.

>
> What I have in mind is sharding a collection of documents between
> several instances of CouchDB each running on their own nodes. Then, I
> want to run distributed map-reduce queries over the whole collection
> of documents. Do I understand correctly that Lounge is currently the
> way to do this?

Lounge is one way. BigCouch (just released) is another.

>
> How would doing something like this with CouchDB and Lounge compare
> with using Hadoop and HBase?

I do not know that much about HBase/Hadoop. I bet someone else on the
list can add more differences, but I know at least there is a data
model difference: CouchDB uses JSON documents but HBase is column
oriented. Also, if HBase relies on HDFS then I think the HDFS name
node is a single point of failure, whereas you can configure BigCouch
and Lounge with redundancy at every level of the system.

-Randall