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From: =?ISO-8859-1?Q?An=EDbal_Rojas?= <anibalrojas@gmail.com>
Date: Tue, 9 Mar 2010 08:21:20 +1930
Message-ID: <dd83951f1003080451k48c92432jfb83e94bdedc850e@mail.gmail.com>
Subject: Use Case scenario: Keeping a window of data + online analytics
To: cassandra-user@incubator.apache.org
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Hello,

    Have been testing alternatives for MySQL / Postgres based app with
the following characteristics:

    - A high rate of inserts. Heavy bursts are expected.
    - A high rate of deletes to remove old data. We keep a window, as
old data is not relevant.
    - Online analytics based on _aging_ and other variables, right now
mostly calculated client side, this means a lot of data transfer.
    - Cloud based deployment ala Amazon. EBS slow disks.

    I have been reading the Wiki, blogs, and mailing list discussions
related to provisioning and performance and I would like to know your
opinion in relation to:

    - Can we keep this "data window" approach, or will a high rate of
delete pose a problem?
    - Also regarding  the "data window", what about replication?
    - Will slow disk performance affect read speed?
    - We need read speed, I understand writes won't be a problem, but
there will be a lot of reads, some of them with large sets of values.
    - What role plays RAM in Cassandra under this scenario?

    Of course we are looking at Cassandra as a possible solution
and/or part of the solution, against / or combined with a in memory
DB.

    Thanks in advance for sharing your experience, and opinions.

--
An=EDbal Rojas
Ruby on Rails Web Developer
http://www.google.com/profiles/anibalrojas