The whole upgrade procedure for Cassandra major versions usually takes around one hour or more, depending on the size of the cluster.
Important: Aiven recommends that you test the upgrade on a fork of an existing database. Testing on a fork provides the benefit of verifying the impact and duration of the upgrade without affecting the running service.
To upgrade a Cassandra service:
Log in to the Aiven web console and select the instance that you want to upgrade.
On the Overview page, scroll down to the Cassandra version section and click Upgrade Cassandra.
Select the version that you want to upgrade to.
Note: When you select the version, the system checks the compatibility of the upgrade.
The system starts applying the upgrade:
The system waits for ongoing repairs to be finished.
The system takes a fresh backup of the Cassandra cluster.
A rolling restart is performed on the cluster, where nodes start the new version one by one. Restarting nodes do not leave the cluster and are perceived as 'down' by other nodes.
sstablesare upgraded on all nodes one by one.
Note: Upgrading the SSTable files to the new format takes a long time. During the upgrade, the cluster should perform without any performance impact.