Cassandra upgrade from 2.0.x to 2.1.x or 3.0.x

Question

I\'ve searched for previous versions of this question, but none seem to fit my case. I have an existing Cassandra cluster running 2.0.x. I\'ve been allocated new VMs, so I d

Answer 1

Don't worry about the migration. You can simply migrate your Cassandra 2.0.X cluster to Cassandra 3.0.X. But its better if you migrate your cluster Cassandra 2.0.X to latest Cassandra 2.X.X then Cassandra 3.0.X. You need to follow some steps-

1. Backup data
2. Uninstall present version
3. Install the version you want to upgrade
4. Restore data

As you are doing migration, you need to be careful about your data always. For the data backup and restore you can follow two ways-

1. Creating snapshots of your sstables and then after installing the new version of cassandra, placing the files to the data location and run sstableloader.
2. Backup your schema's to a .cql file and copy all the tables to .csv and then after installing the new version of cassandra, source your schema from .cql and copy all the tables from every single .csv file.

If you are fully convinced how you will complete the migration then you can write a bash script to complete the backup and restore steps.