Database Reference
In-Depth Information
UN 10.10.21.228 2.05 GB 256 26.1% d3de1... 1a
UN 10.10.21.206 1.92 GB 256 24.2% 7dced... 1a
UN 10.10.21.169 1.84 GB 256 24.7% 55ac5... 1a
UN 10.10.21.7 1.42 GB 256 25.0% 97c2f... 1a
We are done here. A new node is added, and the cluster is all up and balanced. You can
monitor the data transfer using
nodetool -h HOSTNAME netstats
with
HOSTNAME
as the newly added node's address. Once that is done, one may want to run
nodetool -h HOSTNAME cleanup
on each node when all the transfers are done.
Adding a new node to a cluster without vnodes
Clusters without vnodes require some extra work to be done to add a new node. They
need to add a node and make sure the cluster is balanced. The steps are as follows:
•
Ring status
: Use
nodetool -h HOSTNAME ring
to see the current ring dis-
tribution:
$ /opt/cassandra/bin/nodetool status
Datacenter: us-east
==================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns
(effective) Host ID Rack
UN 10.10.21.228 4.55 GB 1
66.7% 5589b... 1a
UN 10.10.21.206 4.54 GB 1
66.7% a3cfc... 1a
UN 10.10.21.169 4.58 GB 1
66.7% 089b2... 1a
The previous sample looks pretty balanced with three nodes and replication factor
of 2
•
New tokens
: Adding additional nodes is going to split the token range into four.
Let's see what they are:
$ python -c 'print [str(((2**64 / 4) * i) - 2**63)
for i in range(4)]'
