Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 59476 invoked from network); 12 Jun 2010 23:32:59 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 12 Jun 2010 23:32:59 -0000 Received: (qmail 79699 invoked by uid 500); 12 Jun 2010 23:32:58 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 79655 invoked by uid 500); 12 Jun 2010 23:32:57 -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 79647 invoked by uid 99); 12 Jun 2010 23:32:57 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 12 Jun 2010 23:32:57 +0000 X-ASF-Spam-Status: No, hits=2.9 required=10.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: local policy) Received: from [209.85.212.44] (HELO mail-vw0-f44.google.com) (209.85.212.44) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 12 Jun 2010 23:32:51 +0000 Received: by vws9 with SMTP id 9so3085312vws.31 for ; Sat, 12 Jun 2010 16:32:29 -0700 (PDT) MIME-Version: 1.0 Received: by 10.220.125.106 with SMTP id x42mr1214004vcr.166.1276385548911; Sat, 12 Jun 2010 16:32:28 -0700 (PDT) Received: by 10.220.195.197 with HTTP; Sat, 12 Jun 2010 16:32:28 -0700 (PDT) In-Reply-To: <29B929EE-2E68-4978-9E16-8CB4417E4E2B@gmail.com> References: <29B929EE-2E68-4978-9E16-8CB4417E4E2B@gmail.com> Date: Sun, 13 Jun 2010 09:32:28 +1000 Message-ID: Subject: Re: Pelops - a new Java client library paradigm From: Dan Washusen To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=001636d340b13d433e0488ddab12 X-Virus-Checked: Checked by ClamAV on apache.org --001636d340b13d433e0488ddab12 Content-Type: text/plain; charset=ISO-8859-1 Thanks for clarifying! On 13 June 2010 09:03, Miguel Verde wrote: > afaik, Cassandra does nothing to guarantee connection-level read your own > writes consistency beyond its usual consistency levels. See > https://issues.apache.org/jira/browse/CASSANDRA-876 and the earlier > http://issues.apache.org/jira/browse/CASSANDRA-132 > > On Jun 12, 2010, at 5:48 PM, Dan Washusen wrote: > > Very nice! > > You mention that the connections are handled internally by Pelops, does > that mean that potentially a different connection is used for each operation > performed? > > I had assumed using the same connection for several operations with > ConsistencyLevel.ONE would provide a basic level of atomicity. For > example, using the same connection for all operations in a web request would > allow the request to read it's own writes. Is that assumption correct and > does that impact on your decision to handle the connections internally to > Pelops? > > Cheers, > Dan > > On 13 June 2010 05:05, Ran Tavory < rantav@gmail.com>wrote: > >> Nice going, Dominic, having a clear API for cassandra is a big step >> forward :) >> Interestingly, at hector we came up with similar approach, just didn't >> find the time for code that, as production systems keep me busy at nights as >> well... We started with the implementation of BatchMutation, but the rest of >> the API improvements are still TODO >> Keep up the good work, competition keeps us healthy ;) >> >> >> On Fri, Jun 11, 2010 at 4:41 PM, Dominic Williams < >> thedwilliams@googlemail.com> wrote: >> >>> Pelops is a new high quality Java client library for Cassandra. >>> >>> It has a design that: >>> * reveals the full power of Cassandra through an elegant "Mutator and >>> Selector" paradigm >>> * generates better, cleaner, less bug prone code >>> * reduces the learning curve for new users >>> * drives rapid application development >>> * encapsulates advanced pooling algorithms >>> >>> An article introducing Pelops can be found at >>> >>> >>> http://ria101.wordpress.com/2010/06/11/pelops-the-beautiful-cassandra-database-client-for-java/ >>> >>> Thanks for reading. >>> Best, Dominic >>> >> >> > --001636d340b13d433e0488ddab12 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks for clarifying!

On 13 June 2= 010 09:03, Miguel Verde <miguelitovert@gmail.com> wrote:
afaik, Cassandra does nothing to guarantee co= nnection-level read your own writes consistency beyond its usual consistenc= y levels. =A0See https://issues.apache.org/jira/browse/CASSANDRA-876= and the earlier =A0http://issues.apache.org/jira/brows= e/CASSANDRA-132

On Jun 12, 2010, at 5:48 PM, Dan= Washusen <dan@rea= ctive.org> wrote:

=
Very nice!=A0

You mention that the connections are handled internal= ly by Pelops, does that mean that potentially a different connection is use= d for each operation performed?

I had assumed using the same connect= ion for several operations with ConsistencyLevel.ONE would provide a basic level of atomicity.=A0 Fo= r example, using the same connection for all operations in a web request wo= uld allow the request to read it's own writes.=A0 Is that assumption co= rrect and does that impact on your decision to handle the connections inter= nally to Pelops?

Cheers,
Dan

On 13 June 2010 05:05,= Ran Tavory <rant= av@gmail.com> wrote:
Nice going, Dominic, having a clear API for cassandra is a= big step forward :)
Interestingly, at hector we came up with similar a= pproach, just didn't find the time for code that, as production systems= keep me busy at nights as well... We started with the implementation of Ba= tchMutation, but the rest of the API improvements are still TODO
Keep up the good work,=A0competition=A0keeps us=A0healthy=A0;)


On Fri, Jun 11, 2010 at 4:4= 1 PM, Dominic Williams <thedwilliams@googlemail.com> wro= te:
Pelops is a new high qu= ality Java client library for Cassandra.

It has a design= that:
* reveals the full power of Cassandra through an elegant "Mutator= and Selector" paradigm
* generates better, cleaner, less bug prone code
* reduces the le= arning curve for new users
* drives rapid application development=
* encapsulates advanced pooling algorithms

An article introducing Pelops can be found at

Thanks for reading.
Best, Dominic



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