Database Reference
In-Depth Information
GB 33.33% -3074457345618258603
10.10.21.206 1a Up Normal 4.54
GB 33.33% 3074457345618258602
10.10.21.7 1a Up Normal 2.89
GB 8.33% 4611686018427387904
•
Move tokens
: Let's balance the nodes by moving data around. We need not touch
Node #1
and
Node #4
. We need to move data from
Node #2
and
Node #3
.
They are the ones with wrong tokens. One of them should have the token as 0,
and another should have token as
4611686018427387904
. This is how we
make this happen:
# Move data on Node #2
$ /opt/cassandra/bin/nodetool -h 10.10.21.169 move
-4611686018427387904
# Cassandra is still unbalanced.# Move data on Node #3
$ /opt/cassandra/bin/nodetool -h 10.10.21.206 move 0
This is a blocking operation, which means you will need to wait until the process
finishes. In a really large cluster with huge data, it may take some time to move
the data. Be patient; this operation moves data. It heavily burdens the network,
and the data size on disks may change. Therefore, it is not ideal to do this task
when your site is running under heavy load. Perform this task at a relatively slow
traffic time. It may be useful to watch streaming statistics on the node using
no-
detool netstats
. Here is an example of how it looks (sampled every 1
second):
$ for i in {1..300} ; do /opt/cassandra/bin/nodetool
-h 10.10.21.169 netstats; sleep 1; done
Mode: NORMAL
Not sending any streams.
Not receiving any streams.
Pool Name Active Pending Completed
Commands n/a 0 1371882
Responses n/a 0 7871820
Mode: MOVING
Not sending any streams.
