Database Reference
In-Depth Information
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Mode: DECOMMISSIONED
Not sending any streams.
Read Repair Statistics:
Attempted: 0
Mismatch (Blocking): 0
Mismatch (Background): 0
Pool Name Active Pending Completed
Commands n/a 1 2
Responses n/a 0 3486231
Here is how the ring looks after we decommissioned two of the nodes:
$ /opt/cassandra/bin/nodetool status
Note: Ownership information does not include topology; for
complete information, specify a keyspace
Datacenter: us-east
=================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns Host
ID Rack
UN 10.10.21.228 3.44 GB 256 50.4% d3de1... 1a
UN 10.10.21.7 2.82 GB 256 49.6% 97c2f... 1a
If you look carefully, you will see the ring is still balanced. This is because virtual nodes
take care of balancing. If we do not have virtual nodes like the versions before Cassandra
Version 1.2, you would find that this leads the cluster imbalance and you have to rebal-
ance it manually.
Removing a dead node
Removing a dead node is closely similar to decommissioning, except for the fact that data
is streamed from replica nodes to other nodes instead of streaming from the node that is
being replaced. Take a look at a cluster with a dead server:
