NDB_RESTORE(1) MySQL Database System NDB_RESTORE(1)NAMEndb_restore - restore a Cluster backup
SYNOPSISndb_restore options
DESCRIPTION
The cluster restoration program is implemented as a separate
command-line utility ndb_restore, which can normally be found in the
MySQL bin directory. This program reads the files created as a result
of the backup and inserts the stored information into the database.
ndb_restore must be executed once for each of the backup files that
were created by the START BACKUP command used to create the backup (see
Section 9.2, “Using The Management Client to Create a Backup”). This is
equal to the number of data nodes in the cluster at the time that the
backup was created.
Note
Before using ndb_restore, it is recommended that the cluster be running
in single user mode, unless you are restoring multiple data nodes in
parallel. See Section 7.4, “Single User Mode”, for more information
about single user mode.
Typical options for this utility are shown here:
ndb_restore [-c connectstring] -n node_id [-m] -b backup_id -r [backup_path=]/path/to/backup/files
The -c option is used to specify a connectstring which tells
ndb_restore where to locate the cluster management server. (See
Section 3.4.2, “The Cluster Connectstring”, for information on
connectstrings.) If this option is not used, then ndb_restore attempts
to connect to a management server on localhost:1186. This utility acts
as a cluster API node, and so requires a free connection “slot” to
connect to the cluster management server. This means that there must be
at least one [api] or [mysqld] section that can be used by it in the
cluster config.ini file. It is a good idea to keep at least one empty
[api] or [mysqld] section in config.ini that is not being used for a
MySQL server or other application for this reason (see Section 3.4.6,
“Defining SQL and Other API Nodes”).
You can verify that ndb_restore is connected to the cluster by using
the SHOW command in the ndb_mgm management client. You can also
accomplish this from a system shell, as shown here:
shell> ndb_mgm -e "SHOW"
-n is used to specify the node ID of the data node on which the backups
were taken.
The first time you run the ndb_restore restoration program, you also
need to restore the metadata. In other words, you must re-create the
database tables — this can be done by running it with the -m option.
Note that the cluster should have an empty database when starting to
restore a backup. (In other words, you should start ndbd with --initial
prior to performing the restore.)
The -b option is used to specify the ID or sequence number of the
backup, and is the same number shown by the management client in the
Backup backup_id completed message displayed upon completion of a
backup. (See Section 9.2, “Using The Management Client to Create a
Backup”.)
The path to the backup directory is required, and must include the
subdirectory corresponding to the ID backup of the backup to be
restored. For example, if the data node's DataDir is
/var/lib/mysql-cluster, then the backup directory is
/var/lib/mysql-cluster/BACKUP, and the backup files for the backup with
the ID 3 can be found in /var/lib/mysql-cluster/BACKUP/BACKUP-3. The
path may be absolute or relative to the directory in which the
ndb_restore executable is located, and may be optionally prefixed with
backup_path=.
Important
When restoring cluster backups, you must be sure to restore all data
nodes from backups having the same backup ID. Using files from
different backups will at best result in restoring the cluster to an
inconsistent state, and may fail altogether.
Important
It is not possible to restore a backup made from a newer version of
MySQL Cluster using an older version of ndb_restore. You can restore a
backup made from a newer version of MySQL to an older cluster, but you
must use a copy of ndb_restore from the newer MySQL Cluster version to
do so.
For example, to restore a cluster backup taken from a cluster running
MySQL 4.1.22 to a cluster running MySQL Cluster 4.1.20, you must use a
copy of ndb_restore from the 4.1.22 distribution.
It is possible to restore a backup to a database with a different
configuration than it was created from. For example, suppose that a
backup with backup ID 12, created in a cluster with two database nodes
having the node IDs 2 and 3, is to be restored to a cluster with four
nodes. Then ndb_restore must be run twice — once for each database node
in the cluster where the backup was taken. However, ndb_restore cannot
always restore backups made from a cluster running one version of MySQL
to a cluster running a different MySQL version. See Section 5.2,
“Cluster Upgrade and Downgrade Compatibility”, for more information.
Note
For more rapid restoration, the data may be restored in parallel,
provided that there is a sufficient number of cluster connections
available. That is, when restoring to multiple nodes in parallel, you
must have an [api] or [mysqld] section in the cluster config.ini file
available for each concurrent ndb_restore process. However, the data
files must always be applied before the logs.
Most of the options available for this program are shown in the
following table:
┌──────────────────────────────────────┬────────────┬───────────────────────────────────────────────────────┬──────────────────────────────┐
│Long Form │ Short Form │ Description │ Default Value │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--ndb-nodeid │ None │ Specify a node │ 0 │
│ │ │ ID for the │ │
│ │ │ ndb_restore │ │
│ │ │ process │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--ndb-optimized-node-selection │ None │ Optimize │ TRUE │
│ │ │ selection of │ │
│ │ │ nodes for │ │
│ │ │ transactions │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--ndb-shm │ None │ Use shared │ FALSE │
│ │ │ memory │ │
│ │ │ connections when │ │
│ │ │ available │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--nodeid │ -n │ Use backup files │ 0 │
│ │ │ from node with │ │
│ │ │ the specified ID │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--parallelism │ -p │ Set from 1 to │ 128 │
│ │ │ 1024 parallel │ │
│ │ │ transactions to │ │
│ │ │ be used during │ │
│ │ │ the │ │
│ │ │ restoration │ │
│ │ │ process │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--print │ None │ Print metadata, data, and log │ FALSE │
│ │ │ to stdout │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--print_data │ None │ Print data to stdout │ FALSE │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--print_log │ None │ Print log to stdout │ FALSE │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--print_meta │ None │ Print metadata to stdout │ FALSE │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--restore_data │ -r │ Restore data and logs │ FALSE │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--backup-id │ -b │ Backup sequence ID │ 0 │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--restore_meta │ -m │ Restore table metadata │ FALSE │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--version │ -V │ Output version information │ [N/A] │
│ │ │ and exit │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--backup_path │ None │ Path to backup files │ ./ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--character-sets-dir │ None │ Specify the directory where │ None │
│ │ │ character set information can │ │
│ │ │ be found │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--connect, --connectstring, or │ -c or -C │ Set the connectstring in │ localhost:1186 │
│ --ndb-connectstring │ │ [nodeid=node_id;][host=]host[:port] │ │
│ │ │ format │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--core-file │ None │ Write a core file in the event of an error │ TRUE │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--debug │ -# │ Output debug log │ d:t:O,/tmp/ndb_restore.trace │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--help or --usage │ -? │ Display help message with available options and │ [N/A] │
│ │ │ current values, then │ │
│ │ │ exit │ │
├──────────────────────────────────────┼────────────┼───────────────────────────────────────────────────────┼──────────────────────────────┤
│--ndb-mgmd-host │ None │ Set the host and port in │ None │
│ │ │ host[:port] │ │
│ │ │ format for the management server to │ │
│ │ │ connect to; this │ │
│ │ │ is the same as --connect, │ │
│ │ │ --connectstring, or │ │
│ │ │ --ndb-connectstring, but without a │ │
│ │ │ way to specify the nodeid │ │
└──────────────────────────────────────┴────────────┴───────────────────────────────────────────────────────┴──────────────────────────────┘
Note
If a table has no explicit primary key, then the output generated when
using the --print includes the table's hidden primary key.
Note
ndb_restore reports both temporary and permanent errors. In the case of
temporary errors, it may able to recover from them. Beginning with
MySQL 4.1.22, it reports Restore successful, but encountered temporary
error, please look at configuration in such cases.
COPYRIGHT
Copyright 2007-2008 MySQL AB
This documentation is free software; you can redistribute it and/or
modify it 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
MySQL AB (http://www.mysql.com/).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬────────────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼────────────────────────────────────┤
│Availability │ SUNWmysqlr, SUNWmysqlu, SUNWmysqlt │
├────────────────────┼────────────────────────────────────┤
│Interface Stability │ Obsolete External │
└────────────────────┴────────────────────────────────────┘
NOTES
Source for mysql is available in the SUNWmysqlS package.
MySQL 4.1 04/13/2008 NDB_RESTORE(1)
