The ndbinfo logbuffers Table

The logbuffer table provides information on NDB Cluster log buffer usage.

The logbuffers table contains the following columns:

  • node_id

    The ID of this data node.

  • log_type

    Type of log. Prior to NDB 7.6.6, one of: REDO or DD-UNDO. In NDB 7.6.6 and later, one of: REDO, DD-UNDO, BACKUP-DATA, or BACKUP-LOG.

  • log_id

    The log ID; for Disk Data undo log files, this is the same as the value shown in the LOGFILE_GROUP_NUMBER column of the INFORMATION_SCHEMA.FILES table as well as the value shown for the log_id column of the ndbinfo logspaces table

  • log_part

    The log part number

  • total

    Total space available for this log

  • used

    Space used by this log


Beginning with NDB 7.6.6, logbuffers table rows reflecting two additional log types are available when performing an NDB backup. One of these rows has the log type BACKUP-DATA, which shows the amount of data buffer used during backup to copy fragments to backup files. The other row has the log type BACKUP-LOG, which displays the amount of log buffer used during the backup to record changes made after the backup has started. One each of these log_type rows is shown in the logbuffers table for each data node in the cluster. These rows are not present unless an NDB backup is currently being performed. (Bug #25822988)