See the section on Replication here http://wiki.apache.org/cassandra/Operations#Replication It talks about how to change the RF and then says you can do the same when change the placement strategy.
It can be done, but is a little messy. Depending on your setup it may also be possible to copy / move the nodes manually by moving sstable files. I've not done it myself, are you able to run a test ? Hope that helps. Aaron On 1 Apr 2011, at 02:04, Jonathan Colby wrote: > > From my understanding of replica copies, cassandra picks which nodes to > replicate the data based on replication strategy, and those same "replica > partner" nodes are always used according to token ring distribution. > > If you change the replication strategy, does cassandra pick new nodes to > replicate to? (for example if you went from simple strategy to a > networkTopology strategy where copies are to be sent to another datacenter) > > If so, do you now have unused replica data on the "old" replica nodes that > you need to clean up manually?
