Mariabackup and BACKUP STAGE Commands

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The BACKUP STAGE commands are a set of commands to make it possible to make an efficient external backup tool. How Mariabackup uses these commands depends on whether you are using the version that is bundled with MariaDB Community Server or the version that is bundled with MariaDB Enterprise Server.

Mariabackup and BACKUP STAGE Commands in MariaDB Community Server

The version of Mariabackup that is bundled with MariaDB Community Server does not yet use the BACKUP STAGE commands in an efficient way. In that version, instead of executing the FLUSH TABLES WITH READ LOCK command to lock the database, it executes the following BACKUP STAGE commands:

BACKUP STAGE START;
BACKUP STAGE BLOCK_COMMIT;

And then to unlock the database when the backup is complete, it executes the following:

BACKUP STAGE END;

Mariabackup and BACKUP STAGE Commands in MariaDB Enterprise Server

The following sections describe how the MariaDB Enterprise Backup version of Mariabackup that is bundled with MariaDB Enterprise Server uses each BACKUP STAGE command in an efficient way.

BACKUP STAGE START in MariaDB Enterprise Server

Mariabackup could perform the following tasks in the START stage:

• Copy all transactional tables.
  • InnoDB (i.e. ibdataN and file extensions .ibd and .isl)
  • Aria (i.e. aria_log_control and file extensions .MAD and .MAI)
• Copy the tail of all transaction logs.
  • The tail of the InnoDB redo log (i.e. ib_logfileN files) will be copied for InnoDB tables.
  • The tail of the Aria redo log (i.e. aria_log.N files) will be copied for Aria tables.

BACKUP STAGE FLUSH in MariaDB Enterprise Server

Mariabackup could perform the following tasks in the FLUSH stage:

• Copy all non-transactional tables that are not in use. This list of used tables is found with SHOW OPEN TABLES.
  • MyISAM (i.e. file extensions .MYD and .MYI)
  • MERGE (i.e. file extensions .MRG)
  • ARCHIVE (i.e. file extensions .ARM and .ARZ)
  • CSV (i.e. file extensions .CSM and .CSV)
• Copy the tail of all transaction logs.
  • The tail of the InnoDB redo log (i.e. ib_logfileN files) will be copied for InnoDB tables.
  • The tail of the Aria redo log (i.e. aria_log.N files) will be copied for Aria tables.

At this point data for all old tables should have been copied (except for some system tables).

BACKUP STAGE BLOCK_DDL in MariaDB Enterprise Server

Mariabackup could perform the following tasks in the BLOCK_DDL stage:

• Copy other files.
  • i.e. file extensions .frm, .isl, .TRG, .TRN, .opt, .par
• Copy the non-transactional tables that were in use during BACKUP STAGE FLUSH.
  • MyISAM (i.e. file extensions .MYD and .MYI)
  • MERGE (i.e. file extensions .MRG)
  • ARCHIVE (i.e. file extensions .ARM and .ARZ)
  • CSV (i.e. file extensions .CSM and .CSV)
• Check ddl.log for DDL executed before the BLOCK DDL stage.
  • The file names of newly created tables can be read from ddl.log.
  • The file names of dropped tables can also be read from ddl.log.
  • The file names of renamed tables can also be read from ddl.log, so the files can be renamed instead of re-copying them.
• Copy changes to system log tables.
• Copy the tail of all transaction logs.
  • The tail of the InnoDB redo log (i.e. ib_logfileN files) will be copied for InnoDB tables.
  • The tail of the Aria redo log (i.e. aria_log.N files) will be copied for Aria tables.

BACKUP STAGE BLOCK_COMMIT in MariaDB Enterprise Server

Mariabackup could perform the following tasks in the BLOCK_COMMIT stage:

• Create a MyRocks checkpoint using the rocksdb_create_checkpoint system variable.
• Copy changes to system log tables.
• Copy changes to statistics tables.
• Copy the tail of all transaction logs.
  • The tail of the InnoDB redo log (i.e. ib_logfileN files) will be copied for InnoDB tables.
  • The tail of the Aria redo log (i.e. aria_log.N files) will be copied for Aria tables.

BACKUP STAGE END in MariaDB Enterprise Server

Mariabackup could perform the following tasks in the END stage:

• Copy the MyRocks checkpoint into the backup.