Upgrade Guide - Scylla 2.2 to 2.3 for Red Hat Enterprise Linux 7 or CentOS 7¶
This document is a step by step procedure for upgrading from Scylla 2.2 to Scylla 2.3, and rollback to 2.2 if required.
- Applicable versions
- Upgrade Procedure
- Upgrade steps
- Rollback Procedure
- Rollback steps
This guide covers upgrading Scylla from the following versions: 2.2.x to Scylla version 2.3.y, on the following platforms:
- Red Hat Enterprise Linux, version 7 and later
- CentOS, version 7 and later
- No longer provide packages for Fedora
Execute the following commands one node at the time, moving to the next node only after the upgrade procedure completed successfully.
A Scylla upgrade is a rolling procedure which does not require full cluster shutdown. For each of the nodes in the cluster, serially (i.e. one at a time), you will:
- Check cluster schema
- Drain node and backup the data
- Backup configuration file
- Stop Scylla
- Download and install new Scylla packages
- Start Scylla
- Validate that the upgrade was successful
Apply the following procedure serially on each node. Do not move to the next node before validating the node is up and running with the new version.
During the rolling upgrade it is highly recommended:
- Not to use new 2.3 features
- Not to run administration functions, like repairs, refresh, rebuild or add or remove nodes
- Not to apply schema changes
Make sure that all nodes have the schema synched prior to upgrade, we won’t survive an upgrade that has schema disagreement between nodes.
Before any major procedure, like an upgrade, it is recommended to backup all the data to an external device. In Scylla, backup is done using the
nodetool snapshot command. For each node in the cluster, run the following command:
nodetool drain nodetool snapshot
Take note of the directory name that nodetool gives you, and copy all the directories having this name under
/var/lib/scylla to a backup device.
When the upgrade is complete (all nodes), the snapshot should be removed by
nodetool clearsnapshot -t <snapshot>, or you risk running out of space.
for conf in $( rpm -qc $(rpm -qa | grep scylla) | grep -v contains ); do sudo cp -v $conf $conf.backup-2.2; done
Before upgrading, check what version you are running now using
rpm -qa | grep scylla-server. You should use the same version in case you want to rollback the upgrade. If you are not running a 2.2.x version, stop right here! This guide only covers 2.2.x to 2.3.y upgrades.
- Update the Scylla RPM repo to 2.3
sudo yum update scylla\* -y
- Check cluster status with
nodetool statusand make sure all nodes, including the one you just upgraded, are in UN status.
curl -X GET "http://localhost:10000/storage_service/scylla_release_version"to check scylla version.
journalctl _COMM=scyllato check there are no new errors in the log.
- Check again after 2 minutes, to validate no new issues are introduced.
Once you are sure the node upgrade is successful, move to the next node in the cluster.
Execute the following commands one node at the time, moving to the next node only after the rollback procedure completed successfully.
The following procedure describes a rollback from Scylla release 2.3.x to 2.2.y. Apply this procedure if an upgrade from 2.2 to 2.3 failed before completing on all nodes. Use this procedure only for nodes you upgraded to 2.3
Scylla rollback is a rolling procedure which does not require full cluster shutdown. For each of the nodes rollback to 2.2, you will:
- Drain the node and stop Scylla
- Retrieve the old Scylla packages
- Restore the configuration file
- Restart Scylla
- Validate the rollback success
- Remove the old repo file.
sudo rm -rf /etc/yum.repos.d/scylla.repo
- Update the Scylla RPM repo to 2.2
sudo yum clean all sudo yum downgrade scylla\* -y
for conf in $( rpm -qc $(rpm -qa | grep scylla) | grep -v contains ); do sudo cp -v $conf.backup-2.2 $conf; done
Restore all tables of system and system_schema from previous snapshot, 2.3 uses a different set of system tables. Reference doc: Restore from a Backup and Incremental Backup
cd /var/lib/scylla/data/keyspace_name/table_name-UUID/snapshots/<snapshot_name>/ sudo cp -r * /var/lib/scylla/data/keyspace_name/table_name-UUID/