Hi everyone, I have 2 C* DCs with 12 nodes in each running 1.2.18. I plan to upgrade them to 2.2.latest and wanted to run by you experts my plan.
1. Install 2.0.latest on one node at a time, start and wait for it to join the ring. 2. Run upgradesstables on this node. 3. Repeat Step 1,2 on each node installing cassandra2.0 in a rolling manner and running upgradesstables in parallel. (Please let me know if running upgrades stables in parallel is not right here. My cluster is not under much load really) 4. Now I will have both my DCs running 2.0.latest. 5. Install cassandra 2.1.latest on one node at a time (same as above) 6. Do I need to run upgradesstables here again after the node has started and joined? (I think yes, but seek advice. https://docs.datastax.com/en/latest-upgrade/upgrade/cassandra/upgrdCassandra.html) 7. Following the above pattern, I would install cassandra2.1 in a rolling manner across 2 DCs (depending on response to 6 I might or might not run upgradesstables) 8. At this point both DCs would have 2.1.latest and again in rolling manner I install 2.2.8. My assumption is that while this upgrade would be happening C* would still be able to serve reads and writes and running different versions at various point in the upgrade process will not affect the apps reading/writing from C*. Thanks