[CASSANDRA-9474] Validate dc information on startup

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 2.1.13, 2.2.5, 3.0.1, 3.1

Environment

Cassandra 2.1.5

• Assignee: Marcus Olsson
• Reporter: Marcus Olsson

Authors

Marcus Olsson

Reviewers

Paulo Motta

• Created: 25/May/15 14:53
• Updated: 16/Apr/19 09:31
• Resolved: 04/Dec/15 19:34

Description

When using GossipingPropertyFileSnitch it is possible to change the data center and rack of a live node by changing the cassandra-rackdc.properties file. Should this really be possible? In the documentation at http://docs.datastax.com/en/cassandra/2.1/cassandra/initialize/initializeMultipleDS.html it's stated that you should Choose the name carefully; renaming a data center is not possible, but with this functionality it doesn't seem impossible(maybe a bit hard with changing replication etc.).

This functionality was introduced by CASSANDRA-5897 so I'm guessing there is some use case for this?

Personally I would want the DC/rack settings to be as restricted as the cluster name, otherwise if a node could just join another data center without removing it's local information couldn't it mess up the token ranges? And suddenly the old data center/rack would loose 1 replica of all the data that the node contains.

Issue Links

• relates to: CASSANDRA-10243 Warn or fail when changing cluster topology live
• relates to: CASSANDRA-10242 Validate rack information on startup