How is data propagated

[MK <st...@gmail.com>]

Say I have a cluster of N nodes and I have started all the nodes with
a replication factor of N. So effectively all data is being mirrored
everywhere.

Now, when I write to a node, how does this data get propagated to the
remaining N-1 nodes.

1) Does this one origin node do N-1 network operations to send the data off
2) or does the data replication happen in some special distributed
manner (say origin node writes it to its neigbhors who further write
it to their neighbors and so on )

I need to know this because I am thinking about what happens when say
the link between two datacenters is down.

Regards,
MK

Re: How is data propagated

[Jonathan Ellis <jb...@gmail.com>]

the former, but also see http://issues.apache.org/jira/browse/CASSANDRA-1530

On Wed, Oct 6, 2010 at 9:22 PM, MK <st...@gmail.com> wrote:
> Say I have a cluster of N nodes and I have started all the nodes with
> a replication factor of N. So effectively all data is being mirrored
> everywhere.
>
> Now, when I write to a node, how does this data get propagated to the
> remaining N-1 nodes.
>
> 1) Does this one origin node do N-1 network operations to send the data off
> 2) or does the data replication happen in some special distributed
> manner (say origin node writes it to its neigbhors who further write
> it to their neighbors and so on )
>
> I need to know this because I am thinking about what happens when say
> the link between two datacenters is down.
>
> Regards,
> MK
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com