Since Hawkular is still primarily in development mode upgrading dependencies, including
databases, is fairly painless. Metrics 0.8.0 however was included in OpenShift 3.1, which
means upgrading Cassandra in Metrics is going to be more involved than upgrading the
parent pom and upgrading our dev environments, e.g., changing ccm cluster. The following
is a brief description of the steps that need to be performed,
Run nodetool drain
Shut down the node
Back up configuration and data files
Install new version of Cassandra
Apply configuration changes (from old version) to new version. This would include files
like cassandra.yaml, cassandra-env.sh, etc.
Start the node
Run nodetool upgradesstables
Repeat for each node in the cluster
These steps can be performed as a rolling upgrade; however, no application schema changes
should be made until the upgrade is complete and until cluster reports schema agreement.
With respect to OpenShift, how much of this needs to be automated? Matt, can you share
some insights here? I would like to figure out sooner rather than later how much work we
think is involved.
Thanks
- John