Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-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 C1F24DFBD for ; Wed, 20 Feb 2013 20:20:40 +0000 (UTC) Received: (qmail 63218 invoked by uid 500); 20 Feb 2013 20:20:38 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 63140 invoked by uid 500); 20 Feb 2013 20:20:38 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 63132 invoked by uid 99); 20 Feb 2013 20:20:38 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 20 Feb 2013 20:20:38 +0000 X-ASF-Spam-Status: No, hits=-2.3 required=5.0 tests=RCVD_IN_DNSWL_MED,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [192.174.58.133] (HELO XEDGEB.nrel.gov) (192.174.58.133) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 20 Feb 2013 20:20:31 +0000 Received: from XHUBA.nrel.gov (10.20.4.58) by XEDGEB.nrel.gov (192.174.58.133) with Microsoft SMTP Server (TLS) id 8.3.245.1; Wed, 20 Feb 2013 13:20:05 -0700 Received: from MAILBOX2.nrel.gov ([fe80::19a0:6c19:6421:12f]) by XHUBA.nrel.gov ([::1]) with mapi; Wed, 20 Feb 2013 13:20:09 -0700 From: "Hiller, Dean" To: "user@cassandra.apache.org" Date: Wed, 20 Feb 2013 13:20:08 -0700 Subject: Re: cassandra vs. mongodb quick question(good additional info) Thread-Topic: cassandra vs. mongodb quick question(good additional info) Thread-Index: Ac4Pp62grpjXirm0TJWSj7H5uVbCbA== 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/14.2.5.121010 acceptlanguage: en-US Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Virus-Checked: Checked by ClamAV on apache.org Heh, we just discovered that mistake a few minutes ago=85.thanks though. I= am now wondering and may run a test cluster with a separate 6 nodes and te= st how compaction is on very large data sets and such. We have tons of res= earch data that sits there so I am wondering if 20T / node is now feasible = with cassandra(I mean if mongodb has a 42T which 10gen was telling my colle= ague, I would think we can with cassandra). Is there any reasons I should know up front that 20T per node won't work. = We have 20 disks per node and this definitely has a different profile than = previous cassandra systems I have setup. We don't need really any caching = as disk access is typically fine on reads. Thanks, Dean From: Bryan Talbot > Reply-To: "user@cassandra.apache.org" > Date: Wednesday, February 20, 2013 1:04 PM To: "user@cassandra.apache.org" > Subject: Re: cassandra vs. mongodb quick question(good additional info) This calculation is incorrect btw. 10,000 GB transferred at 1.25 GB / sec = would complete in about 8,000 seconds which is just 2.2 hours and not 5.5 d= ays. The error is in the conversion (1hr/60secs) which is off by 2 orders = of magnitude since (1hr/3600secs) is the correct conversion. -Bryan On Mon, Feb 18, 2013 at 5:00 PM, Hiller, Dean > wrote: Google "10 gigabit in gigabytes" gives me 1.25 gigabytes/second (yes I cou= ld have divided by 8 in my head but eh=85course when I saw the number, I we= nt duh) So trying to transfer 10 Terabytes or 10,000 Gigabytes to a node that we a= re bringing online to replace a dead node would take approximately 5 days??= ? This means no one else is using the bandwidth too ;). 10,000Gigabytes * 1 = second/1.25 * 1hr/60secs * 1 day / 24 hrs =3D 5.555555 days. This is more = likely 11 days if we only use 50% of the network. So bringing a new node up to speed is more like 11 days once it is crashed.= I think this is the main reason the 1Terabyte exists to begin with, right= ?