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ndbinfoMySQL Cluster Information Database
This chapter contains information about MySQL
Cluster, which is a high-availability, high-redundancy
version of MySQL adapted for the distributed computing environment.
Current releases of MySQL Cluster use versions 6 and 7 of the
NDBCLUSTER storage engine (also known
NDB) to enable running several
computers with MySQL servers and other software in a cluster.
Beginning with MySQL 5.1.24, support for the
NDBCLUSTER storage engine was removed
from the standard MySQL server binaries built by MySQL. Instead,
users of MySQL Cluster binaries built by MySQL should upgrade to the
most recent binary release of MySQL Cluster NDB 6.3 or MySQL Cluster
7.0 for supported platforms — these include RPMs that should
work with most Linux distributions. MySQL Cluster users who build
from source should be aware that, also beginning with MySQL 5.1.24,
NDBCLUSTER sources in the standard
MySQL 5.1 tree are no longer maintained; these users should use the
sources provided for MySQL Cluster NDB 6.2 or later. (Locations
where the sources can be obtained are listed later in this section.)
MySQL Cluster NDB 6.1, 6.2, and 6.3 were formerly known as “MySQL Cluster Carrier Grade Edition”. Beginning with MySQL Cluster NDB 6.2.15 and MySQL Cluster NDB 6.3.14, this term is no longer applied to the MySQL Cluster software — which is now known simply as “MySQL Cluster” — but rather to a commercial licensing and support package. You can learn more about available options for commercial licensing of MySQL Cluster from MySQL Cluster Features, on the MySQL web site.
This chapter contains information about MySQL Cluster in MySQL 5.1 mainline releases through MySQL 5.1.23, MySQL Cluster NDB 6.2 releases through 5.1.44-ndb-6.2.19, MySQL Cluster NDB 6.3 releases through 5.1.44-ndb-6.3.34, MySQL Cluster NDB 7.0 releases through 5.1.44-ndb-7.0.15 and MySQL Cluster NDB 7.1 releases through 5.1.44-ndb-7.1.4. Currently, the MySQL Cluster NDB 6.3 and MySQL Cluster NDB 7.0 (formerly known as “MySQL Cluster NDB 6.4”) release series are Generally Available (GA). MySQL Cluster NDB 6.2, a previous GA release series, is still supported, although we recommend that new deployments use MySQL Cluster NDB 6.3 or MySQL Cluster NDB 7.0. MySQL Cluster NDB 7.1 is currently under development; we expect to make source and binaries built from the MySQL Cluster NDB 7.1 available for evaluation and testing purposes in the near future.
This chapter also contains historical information about MySQL Cluster NDB 6.1, although this release series is no longer in active development, and should not be used in new deployments. Users of MySQL Cluster NDB 6.1 should upgrade to a later MySQL Cluster NDB 6.x or 7.x release series as soon as possible.
Platforms supported. MySQL Cluster is currently available and supported on a number of platforms, including Linux, Solaris, Mac OS X, and other Unix-style operating systems on a variety of hardware. Beginning with MySQL Cluster NDB 7.0, MySQL Cluster is also available (on an experimental basis) on Microsoft Windows platforms. For exact levels of support available for on specific combinations of operating system versions, operating system distributions, and hardware platforms, please refer to http://www.mysql.com/support/supportedplatforms/cluster.html, maintained by the MySQL Support Team on the MySQL web site.
We are continuing to work to make MySQL Cluster available on all operating systems supported by MySQL; we will update the information provided here as this work continues.
Availability. MySQL Cluster NDB 6.2, MySQL Cluster NDB 6.3, and MySQL Cluster NDB 7.0 binary and source packages are available for supported platforms from http://dev.mysql.com/downloads/select.php?id=14.
Binary releases and RPMs were not available for MySQL Cluster NDB 6.2 prior to MySQL Cluster NDB 6.2.15.
MySQL Cluster release numbers.
Starting with MySQL Cluster NDB 6.1 and 6.2, MySQL Cluster follows
a somewhat different release pattern from the mainline MySQL 5.1
Cluster series of releases. In this Manual and other MySQL
documentation, we identify these and later MySQL Cluster releases
employing a version number that begins with “NDB”.
This version number is that of the
NDBCLUSTER storage engine used, and
not of the MySQL server version on which the MySQL Cluster release
Version strings used in MySQL Cluster NDB 6.x and 7.x software. The version string displayed by MySQL Cluster NDB 6.x and 7.x software uses this format:
mysql_server_version represents the
version of the MySQL Server on which the MySQL Cluster release is
based. For all MySQL Cluster NDB 6.x and 7.x releases, this is
ndbcluster_engine_version is the
version of the
engine used by this release of the MySQL Cluster software. You can
see this format used in the mysql client, as
mysqlWelcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.1.44-ndb-7.0.15 Source distribution Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql>
SELECT VERSION()\G*************************** 1. row *************************** VERSION(): 5.1.44-ndb-7.0.15 1 row in set (0.00 sec)
This version string is also displayed in the output of the
SHOW command in the ndb_mgm
SHOWConnected to Management Server at: localhost:1186 Cluster Configuration --------------------- [ndbd(NDB)] 2 node(s) id=1 @10.0.10.6 (5.1.44-ndb-7.0.15, Nodegroup: 0, Master) id=2 @10.0.10.8 (5.1.44-ndb-7.0.15, Nodegroup: 0) [ndb_mgmd(MGM)] 1 node(s) id=3 @10.0.10.2 (5.1.44-ndb-7.0.15) [mysqld(API)] 2 node(s) id=4 @10.0.10.10 (5.1.44-ndb-7.0.15) id=5 (not connected, accepting connect from any host)
The version string identifies the mainline MySQL version from
which the MySQL Cluster release was branched and the version of
NDBCLUSTER storage engine used.
For example, the full version string for MySQL Cluster NDB 7.0.5
(the first GA MySQL Cluster NDB 7.0 binary release) was
mysql-5.1.32-ndb-7.0.5. From this we can
determine the following:
Since the portion of the version string preceding
-ndb-” is the base MySQL
Server version, this means that MySQL Cluster NDB 7.0.5
derives from the MySQL 5.1.32, and contains all feature
enhancements and bugfixes from MySQL 5.1 up to and including
Since the portion of the version string following
-ndb-” represents the
version number of the
NDBCLUSTER) storage engine,
MySQL Cluster NDB 7.0.5 uses version 7.0.5 of the
NDBCLUSTER storage engine.
New MySQL Cluster releases are numbered according to updates in the
NDB storage engine, and do not necessarily
correspond in a linear fashion with mainline MySQL Server releases.
For example, MySQL Cluster NDB 7.0.5 (as previously noted) is based
on MySQL 5.1.32, and MySQL Cluster NDB 7.0.6 is based on MySQL
5.1.34 (version string:
Compatibility with standard MySQL 5.1 releases.
While many standard MySQL schemas and applications can work using
MySQL Cluster, it is also true that unmodified applications and
database schemas may be slightly incompatible or have suboptimal
performance when run using MySQL Cluster (see
Section 17.1.5, “Known Limitations of MySQL Cluster”). Most of these issues
can be overcome, but this also means that you are very unlikely to
be able to switch an existing application datastore — that
currently uses, for example,
InnoDB — to use the
NDB storage engine without allowing
for the possibility of changes in schemas, queries, and
applications. Moreover, from MySQL 5.1.24 onwards, the MySQL
Server and MySQL Cluster codebases diverge considerably (and
NDB storage engine support dropped
from subsequent MySQL Server releases), so that the standard
mysqld cannot function as a dropin replacement
for the version of mysqld that is supplied with
MySQL Cluster development source trees. MySQL Cluster development trees can also be accessed via https://code.launchpad.net/~mysql/:
The MySQL Cluster development sources maintained at https://code.launchpad.net/~mysql/ are licensed under the GPL. For information about obtaining MySQL sources using Bazaar and building them yourself, see Section 2.3.3, “Installing from the Development Source Tree”.
Currently, MySQL Cluster NDB 6.2, MySQL Cluster NDB 6.3, and MySQL Cluster NDB 7.0 releases are all Generally Available (GA), although we recommend that new deployments use MySQL Cluster 6.3 or MySQL Cluster 7.0. MySQL Cluster NDB 7.1 is in early development; we intend to make the source tree for this release series available in the near future. MySQL Cluster NDB 6.1 is no longer in active development. For an overview of major features added in MySQL Cluster NDB 6.x and 7.x, see Section 17.1.4, “MySQL Cluster Development History”.
This chapter represents a work in progress, and its contents are subject to revision as MySQL Cluster continues to evolve. Additional information regarding MySQL Cluster can be found on the MySQL Web site at http://www.mysql.com/products/cluster/.
Additional Resources. More information may be found in the following places:
Answers to some commonly asked questions about Cluster may be found in the Section A.10, “MySQL 5.1 FAQ — MySQL Cluster”.
The MySQL Cluster mailing list: http://lists.mysql.com/cluster.
The MySQL Cluster Forum: http://forums.mysql.com/list.php?25.
Many MySQL Cluster users and some of the MySQL Cluster developers blog about their experiences with Cluster, and make feeds of these available through PlanetMySQL.
If you are new to MySQL Cluster, you may find our Developer Zone article How to set up a MySQL Cluster for two servers to be helpful.