Thanks for your reply. I also think separate rings are more reasonable. So one ring for one dc is only for c* 1.x or 2.x without vnode?
Check these references: https://docs.datastax.com/en/archived/cassandra/1.1/docs/initialize/token_generation.html http://www.luketillman.com/one-token-ring-to-rule-them-all/ https://community.apigee.com/articles/13096/cassandra-token-distribution.html Even the riak official said c* splits the ring across dc: http://basho.com/posts/business/riak-vs-cassandra-an-updated-brief-comparison/ Why they said each dc has its own ring? 2018-04-11 19:55 GMT+08:00 Jacques-Henri Berthemet <jacques-henri.berthe...@genesys.com>: > Hi, > > Each DC has the whole ring, each DC contains a copy of the same data. When > you add replication to a new DC, all data is copied to the new DC. > > Within a DC, each range of token is 'owned' by a (primary) node (and replicas > if you have RF > 1). If you add/remove a node in a DC, tokens will be > rearranged between all nodes within the DC only, the other DCs won't be > affected. > > -- > Jacques-Henri Berthemet > > -----Original Message----- > From: Jinhua Luo [mailto:luajit...@gmail.com] > Sent: Wednesday, April 11, 2018 12:35 PM > To: user@cassandra.apache.org > Subject: does c* 3.0 use one ring for all datacenters? > > Hi All, > > I know it seems a stupid question, but I am really confused about the > documents on the internet related to this topic, especially it seems that it > has different answers for c* with vnodes or not. > > Let's assume the token range is 1-100 for the whole cluster, how does it > distributed into the datacenters? Think that the number of datacenters is > dynamic in a cluster, if there is only one ring, then the token range would > change on each node when I add a new datacenter into the cluster? Then it > would involve data migration? It doesn't make sense. > > Looking forward to clarification for c* 3.0, thanks! > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
