Replacing a node
More often than not, you find yourself in a less than situation where you do not really want to remove a dead node; instead, you want to replace it. The reasons can be many, your cloud service provider finds that a node is sitting on degraded hardware and kills the nodes with a notification mail to you.
All versions after Cassandra Version 1.2 have simplified replacing a node to merely running one command. Here are the steps to replace a node:
Install Cassandra on the new node. Make sure
conf/cassandra.yaml
has all the custom changes that exist in other nodes. (The best way to do this is to copycassandra.yaml
from a live node, and change the node-specific setting.)Make sure you have got the following variables right:
cluster_name
,endpoint_snitch
,listen_address
,broadcast_address
, andseeds
.Make sure the data directories are clean. If you are reusing a node that used to be a part of Cassandra cluster, it can possibly lead to a startup failure if the data directory has old...