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Backup and Restore

Note

This documentation applies to mariadb-operator version >= v0.0.24

mariadb-operator allows you to declarativaly take backups by defining Backup resources and later on restore them by using their Restore counterpart. These resources get reconciled into Job/CronJob resources that automatically perform the backup/restore operations, so you don't need to manually operate your MariaDB.

Refer to the sections below, the API reference and the example suite to see see how to configure the Backup and Restore resources.

Storage types

Currently, the following storage types are supported:

Our recommendation is to store the backups externally in a S3 compatible storage. Minio makes this incredibly easy, take a look at our Minio reference installation to quickly spin up an instance.

Backup

You can take a one-time backup of your MariaDB instance by declaring the following resource:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Backup
metadata:
  name: backup
spec:
  mariaDbRef:
    name: mariadb
  storage:
    persistentVolumeClaim:
      resources:
        requests:
          storage: 100Mi
      accessModes:
        - ReadWriteOnce

This will use the default StorageClass to provision a PVC that would hold the backup files, but ideally you should use a S3 compatible storage:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Backup
metadata:
  name: backup
spec:
  mariaDbRef:
    name: mariadb
  storage:
    s3:
      bucket: backups
      endpoint: minio.minio.svc.cluster.local:9000
      region:  us-east-1
      accessKeyIdSecretKeyRef:
        name: minio
        key: access-key-id
      secretAccessKeySecretKeyRef:
        name: minio
        key: secret-access-key
      tls:
        enabled: true
        caSecretKeyRef:
          name: minio-ca
          key: ca.crt

By providing the authentication details and the TLS configuration via references to Secret keys, this example will store the backups in a local Minio instance.

Scheduling

To minimize the Recovery Point Objective (RPO) and mitigate the risk of data loss, it is recommended to perform backups regularly. You can do so by providing a spec.schedule in your Backup resource:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Backup
metadata:
  name: backup-scheduled
spec:
  mariaDbRef:
    name: mariadb
  schedule:
    cron: "*/1 * * * *"
    suspend: false
...

This resource gets reconciled into a CronJob that periodically takes the backups.

It is important to note that regularly scheduled Backups complement very well the target recovery time feature detailed below.

Retention policy

Given that the backups can consume a substantial amount of storage, it is crucial to define your retention policy by providing the spec.maxRetention field in your Backup resource:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Backup
metadata:
  name: backup-scheduled
spec:
  mariaDbRef:
    name: mariadb
  maxRetention: 720h # 30 days
...

By default, it will be set to 720h (30 days), indicating that backups older than 30 days will be automatically deleted.

Restore

You can easily restore a Backup in your MariaDB instance by creating the following resource:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Restore
metadata:
  name: restore
spec:
  mariaDbRef:
    name: mariadb
  backupRef:
    name: backup

This will trigger a Job that will mount the same storage as the Backup and apply the dump to your MariaDB database.

Nevertheless, the Restore resource doesn't necessarily need to specify a spec.backupRef, you can point to other storage source that contains backup files, for example a S3 bucket:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Restore
metadata:
  name: restore
spec:
  mariaDbRef:
    name: mariadb
  s3:
    bucket: backups
    endpoint: minio.minio.svc.cluster.local:9000
    region:  us-east-1
    accessKeyIdSecretKeyRef:
      name: minio
      key: access-key-id
    secretAccessKeySecretKeyRef:
      name: minio
      key: secret-access-key
    tls:
      enabled: true
      caSecretKeyRef:
        name: minio-ca
        key: ca.crt

Target recovery time

If you have multiple backups available, specially after configuring a scheduled Backup, the operator is able to infer which backup to restore based on the spec.targetRecoveryTime field.

apiVersion: k8s.mariadb.com/v1alpha1
kind: Restore
metadata:
  name: restore
spec:
  mariaDbRef:
    name: mariadb
  backupRef:
    name: backup
  targetRecoveryTime: 2023-12-19T09:00:00Z

The operator will look for the closest backup available and utilize it to restore your MariaDB instance.

By default, spec.targetRecoveryTime will be set to the current time, which means that the latest available backup will be used.

Bootstrap new MariaDB instances from Backups

To minimize your Recovery Time Objective (RTO) and to switfly spin up new clusters from existing Backups, you can provide a Resource source directly in the MariaDB object via the spec.bootstrapFrom field:

apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-from-backup
spec:
  volumeClaimTemplate:
    resources:
      requests:
        storage: 1Gi
    accessModes:
      - ReadWriteOnce

  bootstrapFrom:
    backupRef:
      name: backup
    targetRecoveryTime: 2023-12-19T09:00:00Z

As in the Restore resource, you don't strictly need to specify a reference to a Backup, you can provide other storage types that contain backup files:

apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-from-backup
spec:
  volumeClaimTemplate:
    resources:
      requests:
        storage: 1Gi
    accessModes:
      - ReadWriteOnce

  bootstrapFrom:
    s3:
      bucket: backups
      endpoint: minio.minio.svc.cluster.local:9000
      accessKeyIdSecretKeyRef:
        name: minio
        key: access-key-id
      secretAccessKeySecretKeyRef:
        name: minio
        key: secret-access-key
      tls:
        enabled: true
        caSecretKeyRef:
          name: minio-ca
          key: ca.crt
    targetRecoveryTime: 2023-12-19T09:00:00Z

Under the hood, the operator creates a Restore object just after the MariaDB resource becomes ready.

Minio reference installation

The easiest way to get a S3 compatible storage is Minio. You can install it by using their helm chart, or, if you are looking for a production-grade deployment, take a look at their operator.

In our case, we have have configured a Minio instance for development purposes, you can easily install it by running:

make cluster
make install-minio
make net # to access the console via a MetalLB LoadBalancer: https://minio-console:9001

As an alternative, you can also use play.min.io using these credentials.

Reference