Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cassandra.apache.org
Received-SPF: pass (athena.apache.org: domain of etamme@gmail.com designates
 209.85.161.44 as permitted sender)
MIME-Version: 1.0
Date: Tue, 30 Aug 2011 06:30:38 -0400
Message-ID: 
 <CAJ2KVOqBMP1-0RtqchpJ-G_t23xSdXB1rXHgRh4VAX_uhv1AqQ@mail.gmail.com>
Subject: asynchronous writes (aka consistency = 0)
From: Eric tamme <etamme@gmail.com>
To: user@cassandra.apache.org
Content-Type: text/plain; charset=ISO-8859-1

Is there any mechanism that would allow me to write to Cassandra with
no blocking at all?

I spent a long time figuring out a problem I encountered with one node
in each datacenter: LA, and NY using SS RF=1 and write consistency 1.
My row keys are yyyy-mm-dd-h so basically for every hour a row would
pin to one datacenter and I would get fast writes from one location.
This would change periodically as the hour changed (took forever to
figure out what was going on).

The whole point of switching to SS from NTS was so I could reduce data
redundancy (this is basically throw away data), but the delay in
writing cross country is too high with SS since the minimum
consistency will cause cassandra blocks to ensure there is ONE write
(assuming all nodes are up).

NTS does allow me to localize the block on writes by doing strategy
options NY=1,LA=1.. but then I am back to storing duplicate data.  I'd
like to be able to use SS with RF1 and write consistency=0 (or some
thing like that).

Any thoughts?