Scylla Manager is a centralized cluster administration and recurrent tasks automation tool. Scylla Manager 1.x includes automation of periodic repair, with future releases providing more capabilities, such as rolling upgrades, recurrent backup, and more. With time, Scylla Manager will become the focal point of Scylla Enterprise Cluster Management, including a GUI frontend. Like Scylla Enterprise, Scylla Manager is available for all Scylla customers, or for a 30-day evaluation.
Scylla Manager includes three main parts:
- Scylla-Manager, a Go-based server(daemon) that exposes REST API
- sctool, a CLI tool for interacting with Scylla-Manager
- A highly available backend to persist its state
The Scylla-Manager server interacts securely with one or more Scylla clusters, learns its topology, and runs cluster-wide tasks in a controlled and predictable way. A user can use sctool to initiate and schedule management operations, monitor their progress or suspend them. For the best high availability, Scylla Manager uses ScyllaDB as a persistent backend. By default, Scylla Manager installs one local instance of Scylla as backend. For a highly available management solution, we recommend using a multi-node Scylla cluster as a backend. The Scylla Manager server is stateless and relies on Scylla backend for persistence.
Although possible, we do not recommend using the managed Scylla cluster to store as Scylla Manager backend.
Recurrent Repairs Automation¶
It is highly recommended to run weekly repairs on production Scylla clusters but repairing a full cluster is not an easy task and multiple strategies exist. Scylla manager provides a dedicated solution that leverages Scylla’s thread-per-core architecture for best results. Clusters are repaired node by node, ensuring that each database shard performs exactly one repair task at a time. This gives the best repair parallelism on a node, shortens the overall repair time, and does not introduce unnecessary load. On a shard level, a repair is performed in chunks and can be stopped and resumed.
Working with Scylla Manager: Terms¶
Basic terms used by sctool to interact with Scylla Manager:
- Cluster - A Scylla Cluster managed by Scylla Manager and a Scylla Manager can manage multiple clusters. One can add and remove managed clusters at runtime using sctool.
- Task - A management task, that can be scheduled, started, and stopped by the manager on a particular cluster. There is currently two type of tasks:
- repair - A type of Task which executes a cluster-wide repair of a keyspace where each table repair is defined as a Unit.
- repair_auto_schedule - A type of Task which runs by default every week, reads all the tables from the cluster and creates repair for each. repair_auto_schedule is automatically added when a new cluster is added to Scylla Manager to manage.
- Repair Unit - One execution unit, for example, repair of a particular keyspace. Multiple units can be part of one Task.
- Repair Segment - Each repair unit is internally executed one segment at a time, where each segment is a token range.
Scylla Manager in Action¶
The following example, sctool is used to:
- Managed a new Scylla cluster from Scylla Manager using
sctool cluster add .... This automatically adds all existing keyspace to a repair scheduled
- List managed cluster with
sctool cluster list
- List the repair units with
sctool repair unit listunit list
- List scheduled tasks with
sctool task list
- Add a new repair task with
sctool repair schedule important_data
- Monitor the repair progress with
sctool repair progress
- Stop and Start an ongoing repair task with
sctool task stopand
sctool task start