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From Benjamin>
Subject Re: Data Distribution / Replication
Date Thu, 12 Aug 2010 17:22:49 GMT
On Thu, Aug 12, 2010 at 8:30 AM, Stefan Kaufmann <> wrote:
> Hello again,
> last day's I started several tests with Cassandra and learned quite some facts.
> However, of course, there are still enough things I need to
> understand. One thing is, how the data replication works.
> For my Testing:
> 1. I set the replication Factor to 3, started with 1 active node (the
> seed) and I inserted some test key's.

This is not a correct concept of what a seed is.  I suggest you not
use the word 'seed' for it.

> 2. I started 2 more nodes, which joined the cluster.
> 3. I waited for the data to replicate, which didn't happen.

Correct, you need to run nodetool repair because the nodes were not
present when the writes came in.  You can also use a higher
consistency level to force read repair before returning data, which
will incrementally repair things.

> 4. I inserted more key's, and it looked like they were distributed to
> all three nodes.

Correct, they were up at the time and received the write operations directly.

Seems like you might benefit from reading the operations wiki:


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