Apache Cassandra upgrade 3.X from 2.1

Question

Is it possible to upgrade Apache Cassandra 2.1.9+ to Apache Cassandra 3.1+ directly?

The release notes for 3.0 mention direct upgrades need a minimum of Apache Cassandra

Answer 1

When upgrading from 2.2.8 to 3.11.6 , while upgrading the last node in the cluster, when last node on which the upgrade is left the client is not able to connect to cluster untill upgrade on the last node finishes. We are having a 5 node cassandra cluster running on aws ec2.