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From Ian Danforth <idanfo...@numenta.com>
Subject Specific Question, General Problem
Date Fri, 21 Oct 2011 19:12:03 GMT
All,

 I have a specific question which I think highlights a general problem.

===Specific Question===

I'm seeing read times of 2-300ms for getting a single row. This seems slow,
but is it unusual?

Stack

5 node cluster
Version .86
EC2 m1large machines
ebs drives for all data (I know, I know)

Datamodel

Millions of rows that are at most 1440 columns wide. Each column stores a
single int.

===General Problem===

I don't know what 'normal' is in Cassandra. The docs use terms like 'large'
or 'wide' rows, but I don't have any absolute numbers around that adjective.
I don't know if storing millions of rows in 5 nodes is unusual (maybe people
scale out before they get to this size). Etc.

There are plenty of people here who have an idea of what's normal for their
cluster, but only a very few who know what is normal for Cassandra in
general.

I would love, *love*, to have a document that highlighted this.

Heck I'd love to help build a 'performance calculator' in which you could
put in the number of nodes, and it would tell you how much data it would be
reasonable to store. (Yes I know there are a ton of variables involved.)

Thanks for any light that can be shed on my specific question or the general
problem.

Ian

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