Snitch changes

As you should recall from Chapter 4, Data Centers, the snitch tells Cassandra what your network topology looks like, and therefore, affects data placement in the cluster. If you haven't inserted any data, you can change the snitch without consequence. Otherwise multiple steps are required, as is a full cluster restart, which will result in downtime.

The following procedure should be used to change snitches:

1. Update your topology properties files, which means cassandra-topology.properties or cassandra-rackdc.properties, depending on which snitch you specify. In the case of the PropertyFileSnitch, make sure all nodes have the same file. For GossipingPropertyFileSnitch or EC2MultiRegionSnitch, each node should have a file indicating its place in the topology.

2. Update the snitch in cassandra.yaml. You will need to do this for every node in the cluster.

3. Restart all nodes, one at a time. Any time you make a change to cassandra.yaml, you must restart the node.

4. Change the replication strategy...