[CASSANDRA-10134] Always require replace_address to replace existing address

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.6
• Component/s: Legacy/Distributed Metadata
• Impacts: Docs
• Assignee: Sam Tunnicliffe
• Reporter: Tom Hobbs

Authors

Sam Tunnicliffe

Reviewers

Joel Knighton

• Created: 19/Aug/15 20:29
• Updated: 28/Jan/22 13:30
• Resolved: 27/Apr/16 08:49

Description

Normally, when a node is started from a clean state with the same address as an existing down node, it will fail to start with an error like this:

ERROR [main] 2015-08-19 15:07:51,577 CassandraDaemon.java:554 - Exception encountered during startup
java.lang.RuntimeException: A node with address /127.0.0.3 already exists, cancelling join. Use cassandra.replace_address if you want to replace this node.
	at org.apache.cassandra.service.StorageService.checkForEndpointCollision(StorageService.java:543) ~[main/:na]
	at org.apache.cassandra.service.StorageService.prepareToJoin(StorageService.java:783) ~[main/:na]
	at org.apache.cassandra.service.StorageService.initServer(StorageService.java:720) ~[main/:na]
	at org.apache.cassandra.service.StorageService.initServer(StorageService.java:611) ~[main/:na]
	at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:378) [main/:na]
	at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:537) [main/:na]
	at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:626) [main/:na]

However, if auto_bootstrap is set to false or the node is in its own seed list, it will not throw this error and will start normally. The new node then takes over the host ID of the old node (even if the tokens are different), and the only message you will see is a warning in the other nodes' logs:

logger.warn("Changing {}'s host ID from {} to {}", endpoint, storedId, hostId);

This could cause an operator to accidentally wipe out the token information for a down node without replacing it. To fix this, we should check for an endpoint collision even if auto_bootstrap is false or the node is a seed.