Configure periodic backups of MariaDB

Note

For bare metal and vSphere providers, the MariaDB backup functionality is enabled since Container Cloud 2.27.0 (Cluster release 16.2.0).

After the management cluster deployment, the cluster configuration includes the MariaDB backup functionality. The Kubernetes cron job responsible for the MariaDB backup is enabled by default. For the MariaDB backup workflow, see Mirantis OpenStack for Kubernetes Operations Guide: MariaDB backup workflow.

Warning

For bare metal and vSphere providers, a local volume of only one node of a management cluster is selected when the backup is created for the first time. This volume is used for all subsequent backups.

If the node containing backup data must be redeployed, first move the MySQL backup to another node and update the PVC binding along with the MariaDB backup job to use another node as described in Change the storage node for MariaDB on bare metal and vSphere clusters.

For the OpenStack provider, a backup job is configured to work with the default csi-sc-cinderplugin storage class. With this class, a PV is created as a Cinder volume. This way, it is independent from any of the management cluster nodes.

To manually create a MariaDB database backup, run:

kubectl -n kaas create job --from=cronjob/mariadb-phy-backup mariadb-phy-backup-manual-001

To modify the default backup configuration for MariaDB:

  1. Select from the following options:

    • If the management cluster is not bootstrapped yet, proceed to the next step.

    • If the management cluster is already deployed, verify that the mariadb-phy-backup CronJob object is present:

      kubectl -n kaas get cronjob mariadb-phy-backup

      Example of a positive system response:

      NAME                 SCHEDULE    SUSPEND   ACTIVE   LAST SCHEDULE   AGE
mariadb-phy-backup   0 0 * * *   False     0        6h3m            10d

      If the object is missing, make sure that your management cluster is successfully upgraded to the latest version.

  2. Select from the following options:

    • If the management cluster is not bootstrapped yet, modify cluster.yaml.template using the steps below.

    • If the management cluster is already deployed, modify the configuration kubectl edit <mgmtClusterName> using the steps below. By default, the management cluster name is kaas-mgmt.

  3. Enable the MariaDB backup in the Cluster object:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          ...
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      enabled: true

  4. Modify the configuration as required. By default, the backup is set up as follows:

    • Runs on a daily basis at 00:00 AM

    • Creates full backups daily

    • Keeps 5 latest full backups

    • Saves backups to the mariadb-phy-backup-data PVC

    • The backup timeout is 21600 seconds

    • The backup type is full

    The mariadb-phy-backup cron job launches backups of the MariaDB Galera cluster. The job accepts settings through parameters and environment variables.

  5. Modify the following backup parameters that you can pass to the cron job and override from the Cluster object:

    MariaDB backup: Configuration parameters

    Parameter

    Default

    Description

    --backup-type (string)

    full

    Backup type. The list of possible values include:

    • incremental

      If the newest full backup is older than the value of the full_backup_cycle parameter, the system performs a full backup. Otherwise, the system performs an incremental backup of the newest full backup.

    • full

      Always performs only a full backup.

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      backup_type: incremental

    --backup-timeout (integer)

    21600

    Timeout in seconds for the system to wait for the backup operation to succeed.

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      backup_timeout: 30000

    --allow-unsafe-backup (boolean)

    false

    If set to true, enables the MariaDB cluster backup on a not fully operational cluster where:

    • The current number of ready pods is not equal to MARIADB_REPLICAS

    • Some replicas do not have healthy wsrep statuses

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      allow_unsafe_backup: true

  6. Modify the following environment variables that you can pass to the cron job and override from the Cluster object:

    MariaDB backup: Environment variables

    Variable

    Default

    Description

    MARIADB_BACKUPS_TO_KEEP (integer)

    10

    Number of full backups to keep.

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      backups_to_keep: 3

    MARIADB_BACKUP_PVC_NAME (string)

    mariadb-phy-backup-data

    Persistent volume claim used to store backups.

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      backup_pvc_name: mariadb-phy-backup-data

    MARIADB_FULL_BACKUP_CYCLE (integer)

    604800

    Number of seconds that defines a period between 2 full backups. During this period, incremental backups are performed. The parameter is taken into account only if backup_type is set to incremental. Otherwise, it is ignored. For example, with full_backup_cycle set to 604800 seconds, a full backup is performed weekly and, if cron is set to 0 0 * * *, an incremental backup is performed daily.

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      full_backup_cycle: 70000

    MARIADB_BACKUP_REQUIRED_SPACE_RATIO (floating)

    1.2

    Multiplier for the database size to predict the space required to create a backup, either full or incremental, and perform a restoration keeping the uncompressed backup files on the same file system as the compressed ones.

    To estimate the size of MARIADB_BACKUP_REQUIRED_SPACE_RATIO, use the following formula: size of (1 uncompressed full backup + all related incremental uncompressed backups + 1 full compressed backup) in KB =< (DB_SIZE * MARIADB_BACKUP_REQUIRED_SPACE_RATIO) in KB.

    The DB_SIZE is the disk space allocated in the MySQL data directory, which is /var/lib/mysql, for databases data excluding galera.cache and ib_logfile* files. This parameter prevents the backup PVC from being full in the middle of the restoration and backup procedures. If the current available space is lower than DB_SIZE * MARIADB_BACKUP_REQUIRED_SPACE_RATIO, the backup script fails before the system starts the actual backup and the overall status of the backup job is failed.

    Usage example:

    spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      backup_required_space_ratio: 1.4

Configuration example:

To perform full backups monthly and incremental backups daily at 02:30 AM and keep the backups for the last six months, configure the database backup in your Cluster object as follows:

spec:
  providerSpec:
    value:
      kaas:
        management:
          helmReleases:
          - name: iam
            values:
              keycloak:
                mariadb:
                  conf:
                    phy_backup:
                      enabled: true
                      backups_to_keep: 6
                      schedule_time: '30 2 * * *'
                      full_backup_cycle: 2628000

See also

Change the storage node for MariaDB on bare metal and vSphere clusters