Hey Techpyaasa, Are you aware of this documentation?
https://docs.datastax.com/en/upgrade/doc/upgrade/cassandra/upgrdCassandraDetails.html Basically yes, you can have multiple versions, but you want to make this multi-version time it as short as possible. As it might take few days as it will have 'upgrade sstables' , so just > wanted to know would be there any possibility during this mismatch of c* > version among nodes in cluster during this upgrade process? To make the upgrade as short as possible I use to migrate the whole cluster and only after upgrade sstables. This minimises the time you're running multiple version. The only (soft) limitation, is that you shouldn't be streaming data around (do not bootstrap, repair or remove a node). It might work, that's why I say "soft limitation" but it might not work, there is no guarantee, it mainly depends on changes that were made between versions I believe. C*heers, ----------------------- Alain Rodriguez - @arodream - al...@thelastpickle.com France The Last Pickle - Apache Cassandra Consulting http://www.thelastpickle.com 2016-11-16 11:12 GMT+01:00 techpyaasa . <techpya...@gmail.com>: > Hi all, > > We are currently running c*-2.0.17 with 2 datacenters each with 18 nodes. > > We like to upgrade to c*-2.1.16. Can we upgrade first all nodes(one by > one) in one dc and then go to next data center. > > As it might take few days as it will have 'upgrade sstables' , so just > wanted to know would be there any possibility during this mismatch of c* > version among nodes in cluster during this upgrade process? > > Thanks > Techpyaasa >