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MySQL 5.1 Reference Manual :: 15 MySQL Cluster :: 15.8 On-line Backup of MySQL Cluster :: 15.8.2 Using The Management Client to Create a Backup
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15.8.2. Using The Management Client to Create a Backup

Before starting a backup, make sure that the cluster is properly configured for performing one. (See Section 15.8.4, “Configuration for Cluster Backup”.)

Creating a backup using the management client involves the following steps:

  1. Start the management client (ndb_mgm).

  2. Execute the command START BACKUP.

  3. The management client responds as shown here: 

    Waiting for completed, this may take several minutes
Node 1: Backup backup_id started from node management_node_id

    Here, backup_id is the unique identifier for this particular backup. (This identifier will also be saved in the cluster log, if it has not been configured otherwise.) management_node_id is the node ID of the management to which the management client is connected.

    This means that the cluster has received and processed the backup request. It does not mean that the backup has been completed.

    Note: Backup messages were not recorded in the cluster log in MySQL 5.1.12 or 5.1.13. The logging of backup operations was restored in MySQL 5.1.14 (see Bug#24544).

  4. When the backup is completed, the management client will indicate this as shown here: 

    Node 1: Backup backup_id started from node management_node_id completed
 StartGCP: 417599 StopGCP: 417602
 #Records: 105957 #LogRecords: 0
 Data: 99719356 bytes Log: 0 bytes

    The values shown for StartGCP, StopGCP, #Records, #LogRecords, Data, and Log will vary according to the specifics of your cluster.

Cluster backups are created by default in the BACKUP subdirectory of the DataDir on each data node. This can be overridden for one or more data nodes individually, or for all cluster data nodes in the config.ini file using the BackupDataDir configuration parameter as discussed in Identifying Data Nodes. The backup files created for a backup with a given backup_id are stored in a subdirectory named BACKUP-backup_id in the backup directory.

To abort a backup that is already in progress:

  1. Start the management client.

  2. Execute this command: 

    ndb_mgm> ABORT BACKUP backup_id

    The number backup_id is the identifier of the backup that was included in the response of the management client when the backup was started (in the message Backup backup_id started from node management_node_id).

  3. The management client will acknowledge the abort request with Abort of backup backup_id ordered. Note: At this point, the management client has not yet received a response from the cluster data nodes to this request, and the backup has not yet actually been aborted.

  4. After the backup has been aborted, the management client will report this fact in a manner similar to what is shown here: 

    Node 1: Backup 3 started from 5 has been aborted. Error: 1321 - Backup aborted by user request: Permanent error: User defined error
Node 3: Backup 3 started from 5 has been aborted. Error: 1323 - 1323: Permanent error: Internal error
Node 2: Backup 3 started from 5 has been aborted. Error: 1323 - 1323: Permanent error: Internal error
Node 4: Backup 3 started from 5 has been aborted. Error: 1323 - 1323: Permanent error: Internal error

    In this example, we have shown sample output for a cluster with 4 data nodes, where the sequence number of the backup to be aborted is 3, and the management node to which the cluster management client is connected has the node ID 5. The first node to complete its part in aborting the backup reports that the reason for the abort was due to a request by the user. (The remaining nodes report that the backup was aborted due to an unspecified internal error.) Note: There is no guarantee that the cluster nodes will respond to an ABORT BACKUP command in any particular order.

    The Backup backup_id started from node management_node_id has been aborted messages mean that the backup has been terminated and that all files relating to this backup have been removed from the cluster filesystem.

It is also possible to abort a backup in progress from a system shell using this command: 

shell> ndb_mgm -e "ABORT BACKUP backup_id"

Note: If there is no backup with ID backup_id running when an ABORT BACKUP is issued, the management client makes no response, nor is it indicated in the cluster log that an invalid abort command was sent.