NDB_BLOB_TOOL(1)

NAME
ndb_blob_tool - check and repair BLOB and TEXT columns of NDB Cluster tables

SYNOPSIS

ndb_blob_tool options table [column, ...]

DESCRIPTION

This tool can be used to check for and remove orphaned BLOB column parts from NDB tables, as well as to generate a file listing any orphaned parts. It is sometimes useful in diagnosing and repairing corrupted or damaged NDB tables containing BLOB or TEXT columns.

The basic syntax for ndb_blob_tool is shown here:

    ndb_blob_tool [options] table [column, ...]

Unless you use the --help option, you must specify an action to be performed by including one or more of the options --check-orphans, --delete-orphans, or --dump-file. These options cause ndb_blob_tool to check for orphaned BLOB parts, remove any orphaned BLOB parts, and generate a dump file listing orphaned BLOB parts, respectively, and are described in more detail later in this section.

You must also specify the name of a table when invoking ndb_blob_tool. In addition, you can optionally follow the table name with the (comma-separated) names of one or more BLOB or TEXT columns from that table. If no columns are listed, the tool works on all of the table's BLOB and TEXT columns. If you need to specify a database, use the --database (-d) option.

The --verbose option provides additional information in the output about the tool's progress.

All options that can be used with ndb_mgmd are shown in the following table. Additional descriptions follow the table.

    • --add-missing
    Command-Line Format | --add-missing

    For each inline part in NDB Cluster tables which has no corresponding BLOB part, write a dummy BLOB part of the required length, consisting of spaces.

    • --character-sets-dir
    Command-Line Format | --character-sets-dir=path

    Directory containing character sets.

    • --check-missing
    Command-Line Format | --check-missing

    Check for inline parts in NDB Cluster tables which have no corresponding BLOB parts.

    • --check-orphans
    Command-Line Format | --check-orphans

    Check for BLOB parts in NDB Cluster tables which have no corresponding inline parts.

    • --connect-retries
    Command-Line Format | --connect-retries=#
    Type | Integer
    Default Value | 12
    Minimum Value | 0
    Maximum Value | 12

    Number of times to retry connection before giving up.

    • --connect-retry-delay
    Command-Line Format | --connect-retry-delay=#
    Type | Integer
    Default Value | 5
    Minimum Value | 0
    Maximum Value | 5

    Number of seconds to wait between attempts to contact management server.

    • --connect-string
    Command-Line Format | --connect-string=connection_string
    Type | String
    Default Value | [none]

    Same as --ndb-connectstring.

    • --core-file
    Command-Line Format | --core-file

    Write core file on error; used in debugging.

    • --database=db_name, -d
    Command-Line Format | --database=name
    Type | String
    Default Value | [none]

    Specify the database to find the table in.

    • --defaults-extra-file
    Command-Line Format | --defaults-extra-file=path
    Type | String
    Default Value | [none]

    Read given file after global files are read.

    • --defaults-file
    Command-Line Format | --defaults-file=path
    Type | String
    Default Value | [none]

    Read default options from given file only.

    • --defaults-group-suffix
    Command-Line Format | --defaults-group-suffix=string
    Type | String
    Default Value | [none]

    Also read groups with concat(group, suffix).

    • --delete-orphans
    Command-Line Format | --delete-orphans

    Remove BLOB parts from NDB Cluster tables which have no corresponding inline parts.

    • --dump-file=file
    Command-Line Format | --dump-file=file
    Type | File name
    Default Value | [none]

    Writes a list of orphaned BLOB column parts to file. The information written to the file includes the table key and BLOB part number for each orphaned BLOB part.

    • --help
    Command-Line Format | --help

    Display help text and exit.

    • --login-path
    Command-Line Format | --login-path=path
    Type | String
    Default Value | [none]

    Read given path from login file.

    • --no-login-paths
    Command-Line Format | --no-login-paths

    Skips reading options from the login path file.

    • --ndb-connectstring
    Command-Line Format | --ndb-connectstring=connection_string
    Type | String
    Default Value | [none]

    Set connection string for connecting to ndb_mgmd. Syntax: [nodeid=id;][host=]hostname[:port]. Overrides entries in NDB_CONNECTSTRING and my.cnf.

    • --ndb-mgm-tls
    Command-Line Format | --ndb-mgm-tls=level
    Type | Enumeration
    Default Value | relaxed
    Valid Values | relaxed strict

    Sets the level of TLS support required to connect to the management server; one of relaxed or strict. relaxed (the default) means that a TLS connection is attempted, but success is not required; strict means that TLS is required to connect.

    • --ndb-mgmd-host
    Command-Line Format | --ndb-mgmd-host=connection_string
    Type | String
    Default Value | [none]

    Same as --ndb-connectstring.

    • --ndb-nodeid
    Command-Line Format | --ndb-nodeid=#
    Type | Integer
    Default Value | [none]

    Set node ID for this node, overriding any ID set by --ndb-connectstring.

    • --ndb-optimized-node-selection
    Command-Line Format | --ndb-optimized-node-selection

    Enable optimizations for selection of nodes for transactions. Enabled by default; use --skip-ndb-optimized-node-selection to disable.

    • --ndb-tls-search-path
    Command-Line Format | --ndb-tls-search-path=list
    Type | Path name
    Default Value (Unix) | $HOME/ndb-tls
    Default Value (Windows) | $HOMEDIR/ndb-tls

    Specify a list of directories to search for a CA file. On Unix platforms, the directory names are separated by colons (:); on Windows systems, the semicolon character (;) is used as the separator. A directory reference may be relative or absolute; it may contain one or more environment variables, each denoted by a prefixed dollar sign ($), and expanded prior to use.

    Searching begins with the leftmost named directory and proceeds from left to right until a file is found. An empty string denotes an empty search path, which causes all searches to fail. A string consisting of a single dot (.) indicates that the search path limited to the current working directory.

    If no search path is supplied, the compiled-in default value is used. This value depends on the platform used: On Windows, this is \ndb-tls; on other platforms (including Linux), it is $HOME/ndb-tls. This can be overridden by compiling NDB Cluster using -DWITH_NDB_TLS_SEARCH_PATH.

    • --no-defaults
    Command-Line Format | --no-defaults

    Do not read default options from any option file other than login file.

    • --print-defaults
    Command-Line Format | --print-defaults

    Print program argument list and exit.

    • --usage
    Command-Line Format | --usage

    Display help text and exit; same as --help.

    • --verbose
    Command-Line Format | --verbose

    Provide extra information in the tool's output regarding its progress.

    • --version
    Command-Line Format | --version

    Display version information and exit.
Example

First we create an NDB table in the test database, using the CREATE TABLE statement shown here:

    USE test;
    CREATE TABLE btest (
        c0 BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
        c1 TEXT,
        c2 BLOB
    )   ENGINE=NDB;

Then we insert a few rows into this table, using a series of statements similar to this one:

    INSERT INTO btest VALUES (NULL, 'x', REPEAT('x', 1000));

When run with --check-orphans against this table, ndb_blob_tool generates the following output:

    $> ndb_blob_tool --check-orphans --verbose -d test btest
    connected
    processing 2 blobs
    processing blob #0 c1 NDB$BLOB_19_1
    NDB$BLOB_19_1: nextResult: res=1
    total parts: 0
    orphan parts: 0
    processing blob #1 c2 NDB$BLOB_19_2
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=0
    NDB$BLOB_19_2: nextResult: res=1
    total parts: 10
    orphan parts: 0
    disconnected

The tool reports that there are no NDB BLOB column parts associated with column c1, even though c1 is a TEXT column. This is due to the fact that, in an NDB table, only the first 256 bytes of a BLOB or TEXT column value are stored inline, and only the excess, if any, is stored separately; thus, if there are no values using more than 256 bytes in a given column of one of these types, no BLOB column parts are created by NDB for this column. See Section 13.7, “Data Type Storage Requirements”, for more information.

COPYRIGHT

Copyright © 1997, 2025, Oracle and/or its affiliates.

This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.

This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/.

SEE ALSO
For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/.

AUTHOR
Oracle Corporation (http://dev.mysql.com/).