Please read
https://docs.datastax.com/en/upgrading/docs/datastax_enterprise/upgrdCstarToDSE.html#_general_restrictions
The document is written for DSE Cassandra, but must of it applies to
Apache Cassandra too.
In short, watch out for these:
Client side:
* Check client driver compatibility.
* Set the protocol version explicitly in your application.
* Ensure that the list of initial contact points contains only hosts
with the oldest Cassandra version or protocol version.
Server side:
* Do not enable new features.
* Do not run nodetool repair.
* During the upgrade, do not bootstrap new nodes or decommission
existing nodes.
* Do not enable Change Data Capture (CDC) on a mixed-version cluster.
Upgrade all nodes to DSE 5.1 (equivalent to Apache Cassandra 3.10)
or later before enabling CDC.
* Complete the cluster-wide upgrade before the expiration of
gc_grace_seconds (approximately 13 days) to ensure any repairs
complete successfully.
* Do not issue TRUNCATE or DDL related queries during the upgrade process.
In addition, if using relevant security features:
* Do not change security credentials or permissions until the upgrade
is complete on all nodes.
* If you are not already using Kerberos, do not set up Kerberos
authentication before upgrading. First upgrade the cluster, and then
set up Kerberos.
On 19/10/2022 11:36, Marc Hoppins wrote:
Hi all,
What (if any) problems could we expect from an upgrade?
Ie., If we have 12 nodes and I upgrade them one-at-a-time, some will
be on the new version and others on the old.
Assuming that daily operations continue during this process, could
problems occur with streaming replica from one node to another?
Marc
