Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 85745 invoked from network); 5 May 2010 10:42:27 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 5 May 2010 10:42:27 -0000 Received: (qmail 98604 invoked by uid 500); 5 May 2010 10:42:26 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 98470 invoked by uid 500); 5 May 2010 10:42:23 -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 98460 invoked by uid 99); 5 May 2010 10:42:23 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 May 2010 10:42:23 +0000 X-ASF-Spam-Status: No, hits=2.2 required=10.0 tests=AWL,FREEMAIL_FROM,HTML_MESSAGE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of dsimeonov@gmail.com designates 209.85.160.172 as permitted sender) Received: from [209.85.160.172] (HELO mail-gy0-f172.google.com) (209.85.160.172) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 May 2010 10:42:18 +0000 Received: by gyh4 with SMTP id 4so2211704gyh.31 for ; Wed, 05 May 2010 03:41:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=yHQbTwXI+oOBDtujfixNRE87Sm3ulTE7iF+9vncnFXE=; b=h9TnrtfUUaeIVQ2jp+qTgaHTtrENEyLxvHCqjosasYKLFmDGAJM4kMhYx0n60cbFi4 EefxDJZRpnkicPdVEeQm7ytdJ+La/rxQ+S343PfovC1a99cpdCeJdGUN1TOOZZO4EmFk E8tVMNuOuOMuddalF0upYGgbYiTfOHmJ06vrM= 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=bYk8Q71YPOsDXLv7J8Gh9MCwkHa5Z6kNKaxuc38dv+Q5iJLk/Ok2YxLZeDEHzYQN6H SDydjomTzaLQYXw30Vq8hpJLM00X1YnfeyiuenYp6tmzYC4ta0Kr8eGDPdfI+Rw3pSEw Njy+N0DEdJTTbCJFPoxME6wpC3mowsHv53tv4= MIME-Version: 1.0 Received: by 10.100.50.24 with SMTP id x24mr1691668anx.4.1273056116538; Wed, 05 May 2010 03:41:56 -0700 (PDT) Received: by 10.100.152.11 with HTTP; Wed, 5 May 2010 03:41:56 -0700 (PDT) In-Reply-To: References: Date: Wed, 5 May 2010 13:41:56 +0300 Message-ID: Subject: Re: eventuality From: =?UTF-8?B?0JTQsNC90LjQtdC7INCh0LjQvNC10L7QvdC+0LI=?= To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=001485f90f669b66930485d679de --001485f90f669b66930485d679de Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi, You are right, but I have the feeling that this is a different use cases= , i.e. we have a happy case (eventuality when everything is up and working) and not so happy one to say. Best regards, Daniel. 2010/5/5 Peter Sch=C3=BCller > > I have one question about the eventuality, i.e. do you know what are > the > > variables from which it depends. Well the most obvoius is the > > ConsistencyLevel, so lets assume it is set to ONE. The question is that > the > > eventuallity is the relative time to spread changes across the cassandr= a > > nodes. I suspect that the most important variables are the network > latency > > and utilization (number of replicas) and number of concurrent requests > from > > clients, I think the other variables like CPU power and memory are not = so > > important. Do you have practical observations about this topic. Thank y= ou > > very much! > > Don't forget nodes going down. The "ONE" node that took your write > could have gone down immediately afterwards. "Eventually" can be a > significant period into the future. > > -- > / Peter Schuller aka scode > --001485f90f669b66930485d679de Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi,
=C2=A0=C2=A0 You are right, but I have the feeling that this is a di= fferent use cases, i.e. we have a happy case (eventuality when everything i= s up and working) and not so happy one to say.
Best regards, Daniel.
=
2010/5/5 Peter Sch=C3=BCller <scode@spotify.com>
> =C2=A0=C2=A0 I have one question abo= ut the eventuality, i.e. do you know what are the
> variables from which it depends. Well the most obvoius is the
> ConsistencyLevel, so lets assume it is set to ONE. The question is tha= t the
> eventuallity is the relative time to spread changes across the cassand= ra
> nodes. I suspect that the most important variables are=C2=A0 the netwo= rk latency
> and utilization (number of replicas) and number of concurrent requests= from
> clients, I think the other variables like CPU power and memory are not= so
> important. Do you have practical observations about this topic. Thank = you
> very much!

Don't forget nodes going down. The "ONE" node tha= t took your write
could have gone down immediately afterwards. "Eventually" can be = a
significant period into the future.

--
/ Peter Schuller aka scode

--001485f90f669b66930485d679de--