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From Matthew Johnson <>
Subject RE: Start with single node, move to 3-node cluster
Date Tue, 26 May 2015 14:02:54 GMT
Hi Jason,

When the 3N cluster is up and running, I need to get the data from SN into
the 3N cluster and then give the SN server back. So I need to keep the
data, but on completely new servers – just trying to work out what the best
way of doing that is. The volume of data that needs migrating won’t be
huge, probably about 30G, but it is data that I definitely need to keep
(for historical analysis, audit etc).



*From:* Jason Wee []
*Sent:* 26 May 2015 14:38
*Subject:* Re: Start with single node, move to 3-node cluster

will you add this lent one node into the 3N to form a cluster? but really ,
if you are just started, you could use this one node for your learning by
installing multiple instances for experiments or development purposes only.
imho, in the long run, this proove to be very valuable, as least for me.

with this single node, you can easily simulate like c* upgrade. for
instance, c* right now is at 2.1.5, when 2.2 went stable, you can test
using your multiple instances on this single node to simulate your
production environment safely.



On Tue, May 26, 2015 at 9:24 PM, Matthew Johnson <>

Hi gurus,

We have ordered some hardware for a 3-node cluster, but its ETA is 6 to 8
weeks. In the meantime, I have been lent a single server that I can use. I
am wondering what the best way is to set up my single node (SN), so I can
then move to the 3-node cluster (3N) when the hardware arrives.

Do I:

1.       Create my keyspaces on SN with RF=1, and when 3N is up and running
migrate all the data manually (either through Spark, dump-and-load, or
write a small script)?

2.       Create my keyspaces on SN with RF=3, bootstrap the 3N nodes into a
4-node cluster when they’re ready, then remove SN from the cluster?

3.       Use SN as normal, and when 3N hardware arrives, physically move
the data folder and commit log folder onto one of the nodes in 3N and start
it up as a seed?

4.       Any other recommended solutions?

I’m not even sure what the impact would be of running a single node with
RF=3 – would this even work?

Any ideas would be much appreciated.



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