Related JIRA ticket: https://issues.apache.org/jira/browse/CASSANDRA-15588
Description: "We've historically had numerous bugs concerning upgrading clusters from one version to the other. Let's establish the supported upgrade path and ensure that users can safely perform the upgrades in production." So the topic of discussion here: what is our supported upgrade path to 4.0? Is this actually documented on our site or in our documentation? Spent a few minutes poking around and didn't find anything. Anyone have an opinion here or any formal prior art for us to build on?
