17.4.19 ndbd_redo_log_reader — Check and Print Content of Cluster Redo Log

Reads a redo log file, checking it for errors, printing its contents in a human-readable format, or both. ndbd_redo_log_reader is intended for use primarily by MySQL Cluster developers and Support personnel in debugging and diagnosing problems.

This utility was made available as part of default builds beginning with MySQL Cluster NDB 6.1.3. It remains under development, and its syntax and behavior are subject to change in future releases. For this reason, it should be considered experimental at this time.

The C++ source files for ndbd_redo_log_reader can be found in the directory /storage/ndb/src/kernel/blocks/dblqh/redoLogReader.

The following table includes options that are specific to the MySQL Cluster program ndbd_redo_log_reader. Additional descriptions follow the table. For options common to most MySQL Cluster programs (including ndbd_redo_log_reader), see Section 17.4.26, “Options Common to MySQL Cluster Programs — Options Common to MySQL Cluster Programs”.

Table 17.81  This table describes command-line options for the ndbd_redo_log_reader program

Format Description Added or Removed


Do not print records

All MySQL 5.1 based releases


Do not check records for errors

All MySQL 5.1 based releases


Print usage information

ADDED: NDB 6.3.53, NDB 7.0.41, NDB 7.1.30


ndbd_redo_log_reader file_name [options]

file_name is the name of a cluster redo log file. redo log files are located in the numbered directories under the data node's data directory (DataDir); the path under this directory to the redo log files matches the pattern ndb_#_fs/D#/LCP/#/T#F#.Data. In each case, the # represents a number (not necessarily the same number). For more information, see MySQL Cluster Data Node File System Directory Files.

The name of the file to be read may be followed by one or more of the options listed here:

Like ndb_print_backup_file and ndb_print_schema_file (and unlike most of the NDB utilities that are intended to be run on a management server host or to connect to a management server) ndbd_redo_log_reader must be run on a cluster data node, since it accesses the data node file system directly. Because it does not make use of the management server, this utility can be used when the management server is not running, and even when the cluster has been completely shut down.