Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 49937 invoked from network); 5 Apr 2010 08:54:37 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 5 Apr 2010 08:54:37 -0000 Received: (qmail 93498 invoked by uid 500); 5 Apr 2010 08:54:36 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 93325 invoked by uid 500); 5 Apr 2010 08:54:36 -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 93317 invoked by uid 99); 5 Apr 2010 08:54:35 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 05 Apr 2010 08:54:35 +0000 X-ASF-Spam-Status: No, hits=1.1 required=10.0 tests=AWL,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of beuknight@gmail.com designates 74.125.82.172 as permitted sender) Received: from [74.125.82.172] (HELO mail-wy0-f172.google.com) (74.125.82.172) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 05 Apr 2010 08:54:30 +0000 Received: by wyb29 with SMTP id 29so1564574wyb.31 for ; Mon, 05 Apr 2010 01:54:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:content-type; bh=piR4qacgpzPUvUYIvfSTgSuLjYh0AZYiDtkfHnn0NgE=; b=yF9joNKqt6WOuBdLfXWy6pWqMSPnyINS85qhK5SVJIaP7VPkLK/BnDSOt5Hlr4NSU1 IVeTKZnQoRLBOa7H2H8Xf4/bFBaKmoy5DZSYuOg46uayQmFZi2eIEX4J5dfLomN/F6Tl 9Zzc6oy88O9797oFlA492K0i7gqsDDWwfjSF8= 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=C50jJHLcEfy/elPHK7msAGSuMl3xSr/0mQjgx6nKZcoskSLpWlsa9guy2XCHm2Jtmo EoxFjiKZpjTwyq4yHtDGkSVtLQ8u1aFcj/jmexzV7yjVXB8B/GpKdPvgFwf5lC9D/iTS P4FECtPbbveLhXf1pr36H/OtF7vrkhVU/0rtY= MIME-Version: 1.0 Received: by 10.216.50.207 with HTTP; Mon, 5 Apr 2010 01:54:08 -0700 (PDT) In-Reply-To: <4BB99AB8.9010408@fourkitchens.com> References: <4BB95C90.7040307@fourkitchens.com> <4BB99AB8.9010408@fourkitchens.com> Date: Mon, 5 Apr 2010 04:54:08 -0400 Received: by 10.216.88.12 with SMTP id z12mr3439146wee.165.1270457648767; Mon, 05 Apr 2010 01:54:08 -0700 (PDT) Message-ID: Subject: Re: Cassandra Design or another solution From: JKnight JKnight To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=0016e6da7ae5db639f048379789b --0016e6da7ae5db639f048379789b Content-Type: text/plain; charset=ISO-8859-1 Thanks David, But what's does "monotonicity" mean? User's score belongs to their action. When they win the game or sale something, user's score will increase. When user lose the game or buy something, user's score will decrease. On Mon, Apr 5, 2010 at 4:09 AM, David Strauss wrote: > I need the question about monotonicity answered, too. > > You should also know: Cassandra is not ideal for directly tracking > values you increment or decrement. > > On 2010-04-05 08:04, JKnight JKnight wrote: > > Thanks for for reply, David. > > > > I will tell more the detail about the system. My system is used to store > > the score (point) user earn when they play game. > > > > "Mark" is the score. > > User's score changes when user win game, buy or sell anything. > > > > Sorry I make a mistake. My data model is: > > > > Mark{ //Column Family > > gameId:{ //row key > > mark_userId: ""// (column name : value), > > mark2_userId2: "" > > }, > > gameId2:{//row key > > mark_userId: "" > > } > > } > > > > > > On Sun, Apr 4, 2010 at 11:44 PM, David Strauss > > wrote: > > > > On 2010-04-05 02:48, JKnight JKnight wrote: > > > I want to design the data storage to store user's mark for a large > > > amount of user. When system run, user's mark changes frequently. > > > > What is a "mark"? > > > > > I want to list top 10 user have largest mark. > > > > Do the "marks" increase monotonically? What other properties do they > > have? > > > > > Could we use Cassandra for store this data? > > > > > > Ex, here my Cassandra data model design: > > > Mark{ > > > userId{ > > > mark_userId > > > }, > > > } > > > > I do not understand that notation. What parts are the CF, key/row, > and > > column? > > > > > When user's mark changes, we remove old mark_userId and add new > > > mark_userId. > > > Because user's mark change frequently and with large amount of > > user, I > > > think Cassandra can not satisfy. > > > > On the contrary, Cassandra excels at tracking rapidly changing data > and > > even shards rows to scale I/O horizontally. > > > > -- > > David Strauss > > | david@fourkitchens.com > > Four Kitchens > > | http://fourkitchens.com > > | +1 512 454 6659 [office] > > | +1 512 870 8453 [direct] > > > > > > > > > > -- > > Best regards, > > JKnight > > > -- > David Strauss > | david@fourkitchens.com > | +1 512 577 5827 [mobile] > Four Kitchens > | http://fourkitchens.com > | +1 512 454 6659 [office] > | +1 512 870 8453 [direct] > > -- Best regards, JKnight --0016e6da7ae5db639f048379789b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks David,
But what's does "monotonicity" mean?
User's score belongs to their action. When they win the game or sale= something, user's score=A0 will increase. When user lose the game or b= uy something, user's score will decrease.

On Mon, Apr 5, 2010 at 4:09 AM, David Straus= s <david@fou= rkitchens.com> wrote:
I need the question about monotonicity answered, too.

You should also know: Cassandra is not ideal for directly tracking
values you increment or decrement.

On 2010-04-05 08:04, JKnight JKnight wrote:
> Thanks for for reply, David.
>
> I will tell more the detail about the system. My system is used to sto= re
> the score (point) user earn when they play game.
>
> "Mark" is the score.
> User's score changes when user win game, buy or sell anything.
>
> Sorry I make a mistake. My data model is:
>
> Mark{ //Column Family
> =A0 =A0 gameId:{ //row key
> =A0 =A0 =A0 =A0 mark_userId: ""// (column name : value),
> =A0 =A0 =A0 =A0 mark2_userId2: ""
> =A0 =A0 },
> =A0 =A0 gameId2:{//row key
> =A0 =A0 =A0 =A0 mark_userId: ""
> =A0 =A0 }
> }
>
>
> On Sun, Apr 4, 2010 at 11:44 PM, David Strauss <david@fourkitchens.com
> <mailto:david@fourkitchens.com>> wrote:
>
> =A0 =A0 On 2010-04-05 02:48, JKnight JKnight wrote:
> =A0 =A0 > I want to design the data storage to store user's mar= k for a large
> =A0 =A0 > amount of user. When system run, user's mark changes = frequently.
>
> =A0 =A0 What is a "mark"?
>
> =A0 =A0 > I want to list top 10 user have largest mark.
>
> =A0 =A0 Do the "marks" increase monotonically? What other pr= operties do they
> =A0 =A0 have?
>
> =A0 =A0 > Could we use Cassandra for store this data?
> =A0 =A0 >
> =A0 =A0 > Ex, here my Cassandra data model design:
> =A0 =A0 > Mark{
> =A0 =A0 > =A0 =A0 userId{
> =A0 =A0 > =A0 =A0 =A0 =A0 mark_userId
> =A0 =A0 > =A0 =A0 },
> =A0 =A0 > }
>
> =A0 =A0 I do not understand that notation. What parts are the CF, key/= row, and
> =A0 =A0 column?
>
> =A0 =A0 > When user's mark changes, we remove old mark_userId a= nd add new
> =A0 =A0 > mark_userId.
> =A0 =A0 > Because user's mark change frequently and with large = amount =A0of
> =A0 =A0 user, I
> =A0 =A0 > think Cassandra can not satisfy.
>
> =A0 =A0 On the contrary, Cassandra excels at tracking rapidly changing= data and
> =A0 =A0 even shards rows to scale I/O horizontally.
>
> =A0 =A0 --
> =A0 =A0 David Strauss
> =A0 =A0 =A0 | david@fo= urkitchens.com <mailto:dav= id@fourkitchens.com>
> =A0 =A0 Four Kitchens
> =A0 =A0 =A0 | ht= tp://fourkitchens.com
> =A0 =A0 =A0 | +1 512 454 6659 [office]
> =A0 =A0 =A0 | +1 512 870 8453 [direct]
>
>
>
>
> --
> Best regards,
> JKnight


--
David Strauss
=A0 | david@fourkitchens.com=
=A0 | +1 512 577 5827 [mobile]
Four Kitchens
=A0 | http://fourkit= chens.com
=A0 | +1 512 454 6659 [office]
=A0 | +1 512 870 8453 [direct]




--
Best regard= s,
JKnight
--0016e6da7ae5db639f048379789b--