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From Per Olesen <>
Subject Re: Quick help on Cassandra please: cluster access and performance
Date Wed, 09 Jun 2010 19:33:20 GMT
> How to set  "write and read with QUORUM"?

You set this through each thrift api call you are making through your java code. See

> They are run physically separate hw (But same since they are VM)

So they share disk.

I think this can have an influence. As I understand it, cassandra can be fast on writes because
its storage format is designed so that it needs to do very few random io, which results in
fever seeks. And I think part of the good read performance comes from data on keys being distributed
onto different nodes, which then means distributed reads on separate disks.

When nodes share disk, I think a lot of this is negated.

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