[CASSANDRA-4092] Allow getting a simple Token->node map over thrift

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 1.1.1
• Assignee: Sam Tunnicliffe
• Reporter: Nick Bailey

Authors

Sam Tunnicliffe

Reviewers

Nick Bailey

• Created: 27/Mar/12 20:48
• Updated: 16/Apr/19 09:32
• Resolved: 10/Apr/12 20:28

Description

Right now the thrift describe_ring call is intended to be used to determine ownership for a keyspace. It can also (and often is) be used by clients to just get a view of what the ring looks like. Since it requires a keyspace as an argument though, it can sometimes be impossible to see what the ring looks like. For example, in a 2 DC/2 node ring where keyspace X exists only dc1. The results of 'describe_ring X' would look something like (with tokens 0 and 10):

{[0,10]: [node0], [10,0]: [node0]}

This is indicating that node0 owns everything for that keyspace since it only exists in 1 datacenter. From this output though it is impossible to tell which token (0 or 10) node0 owns, as well as what the other node in the cluster is.

There are two options here.

• Allow running describe_ring with no parameters to get a view of token->ip without taking replication into consideration.
• Add a new thrift call to achieve this.