MySQL NDB Cluster is a
high-availability, high-redundancy version of MySQL adapted for the
distributed computing environment. Recent NDB Cluster release series
use version 7 of the
NDB storage engine
(also known as
NDBCLUSTER) to enable
running several computers with MySQL servers and other software in a
cluster. NDB Cluster 7.6, now available as a General Availability
(GA) release beginning with version 7.6.6, incorporates version 7.6
NDB storage engine. NDB Cluster 7.5, still
available as a GA release, uses version 7.5 of
NDB. Previous GA releases still available for use
in production, NDB Cluster 7.3 and NDB Cluster 7.4, incorporate
NDB versions 7.3 and 7.4, respectively. NDB
Cluster 7.2, which uses version 7.2 of the
storage engine, is a previous GA release that is currently still
maintained; 7.2 users are encouraged to upgrade to NDB 7.5 or NDB
Support for the
NDB storage engine is
not included in standard MySQL Server 5.6 binaries built by Oracle.
Instead, users of NDB Cluster binaries from Oracle should upgrade to
the most recent binary release of NDB Cluster for supported
platforms—these include RPMs that should work with most Linux
distributions. NDB Cluster users who build from source should use
the sources provided for NDB Cluster. (Locations where the sources
can be obtained are listed later in this section.)
This chapter contains information about NDB Cluster 7.3 releases through 5.6.44-ndb-7.3.26 as well as NDB Cluster 7.4 releases through 5.6.44-ndb-7.4.25. NDB Cluster 7.6 is now available as a General Availability release, and recommended for new deployments; for information about NDB Cluster 7.6, see What is New in NDB Cluster 7.6. NDB Cluster 7.5, 7.4, and 7.3 are previous GA releases still supported in production. NDB Cluster 7.2 is a previous GA release series which is still supported, although we recommend that new deployments for production use NDB Cluster 7.6 (see MySQL NDB Cluster 7.5 and NDB Cluster 7.6). For more information about NDB Cluster 7.2, see MySQL NDB Cluster 7.2.
NDB Cluster 8.0 is now available as a Developer Preview release for
evaluation and testing of new features in the
NDBCLUSTER storage engine; for more information,
see MySQL NDB Cluster 8.0.
Supported Platforms. NDB Cluster is currently available and supported on a number of platforms. For exact levels of support available for on specific combinations of operating system versions, operating system distributions, and hardware platforms, please refer to https://www.mysql.com/support/supportedplatforms/cluster.html.
Availability. NDB Cluster binary and source packages are available for supported platforms from https://dev.mysql.com/downloads/cluster/.
NDB Cluster release numbers.
NDB Cluster follows a somewhat different release pattern from the
mainline MySQL Server 5.6 series of releases. In this
Manual and other MySQL documentation, we
identify these and later NDB Cluster releases employing a version
number that begins with “NDB”. This version number is
that of the
NDBCLUSTER storage engine
used in the release, and not of the MySQL server version on which
the NDB Cluster release is based.
Version strings used in NDB Cluster software. The version string displayed by NDB Cluster programs uses this format:
mysql_server_version represents the
version of the MySQL Server on which the NDB Cluster release is
based. For all NDB Cluster 7.3 and current NDB Cluster 7.4 releases,
this is “5.6”.
ndb_engine_version is the version of the
NDB storage engine used by this release
of the NDB Cluster software. You can see this format used in the
mysql client, as shown here:
shell> mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.6.44-ndb-7.4.25 Source distribution Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql> SELECT VERSION()\G *************************** 1. row *************************** VERSION(): 5.6.44-ndb-7.4.25 1 row in set (0.00 sec)
This version string is also displayed in the output of the
SHOW command in the ndb_mgm
ndb_mgm> SHOW Connected to Management Server at: localhost:1186 Cluster Configuration --------------------- [ndbd(NDB)] 2 node(s) id=1 @10.0.10.6 (5.6.44-ndb-7.4.25, Nodegroup: 0, *) id=2 @10.0.10.8 (5.6.44-ndb-7.4.25, Nodegroup: 0) [ndb_mgmd(MGM)] 1 node(s) id=3 @10.0.10.2 (5.6.44-ndb-7.4.25) [mysqld(API)] 2 node(s) id=4 @10.0.10.10 (5.6.44-ndb-7.4.25) id=5 (not connected, accepting connect from any host)
The version string identifies the mainline MySQL version from which
the NDB Cluster release was branched and the version of the
NDB storage engine used. For example,
the full version string for NDB 7.4.4 (the first NDB Cluster 7.4 GA
mysql-5.6.23-ndb-7.4.4. 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 NDB 7.4.4 derives from MySQL 5.6.23, and contains all feature enhancements and bug fixes from MySQL 5.6 up to and including MySQL 5.6.23.
New NDB Cluster releases are numbered according to updates in the
NDB storage engine, and do not necessarily
correspond in a one-to-one fashion with mainline MySQL Server
releases. For example, NDB 7.4.4 (as previously noted) is based on
MySQL 5.6.23, while NDB 7.4.3 was based on MySQL 5.6.22 (version
Compatibility with standard MySQL 5.6 releases.
While many standard MySQL schemas and applications can work using
NDB Cluster, it is also true that unmodified applications and
database schemas may be slightly incompatible or have suboptimal
performance when run using NDB Cluster (see
Section 3.7, “Known Limitations of NDB 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. In addition, the MySQL Server and NDB Cluster
codebases diverge considerably, so that the standard
mysqld cannot function as a drop-in replacement
for the version of mysqld supplied with NDB
NDB Cluster development source trees. NDB Cluster development trees can also be accessed from https://github.com/mysql/mysql-server.
The NDB Cluster development sources maintained at https://github.com/mysql/mysql-server are licensed under the GPL. For information about obtaining MySQL sources using Git and building them yourself, see Installing MySQL Using a Development Source Tree.
As with MySQL Server 5.6, NDB Cluster 7.3 and NDB Cluster 7.4 releases are built using CMake.
NDB Cluster 7.3 and NDB Cluster 7.4 are previous General Availability (GA) releases still supported in production. We recommend that new deployments for production use NDB Cluster 7.6 (see MySQL NDB Cluster 7.5 and NDB Cluster 7.6). NDB Cluster 7.5, 7.4, and 7.3 are previous General Availability (GA) releases. For an overview of major features added in NDB Cluster 7.6, see What is New in NDB Cluster 7.6. For similar information about NDB Cluster 7.5, see What is New in NDB Cluster 7.5. NDB Cluster 7.2 is a previous GA release that is still maintained (NDB Cluster 7.1 and earlier versions are no longer in active development); for information about NDB 7.2, see MySQL NDB Cluster 7.2.
This chapter represents a work in progress, and its contents are subject to revision as NDB Cluster continues to evolve. Additional information regarding NDB Cluster can be found on the MySQL website at http://www.mysql.com/products/cluster/.
Additional Resources. More information about NDB Cluster can be found in the following places:
For answers to some commonly asked questions about NDB Cluster, see Appendix A, MySQL 5.6 FAQ: NDB Cluster.
The NDB Cluster mailing list: http://lists.mysql.com/cluster.
The NDB Cluster Forum: https://forums.mysql.com/list.php?25.
Many NDB Cluster users and developers blog about their experiences with NDB Cluster, and make feeds of these available through PlanetMySQL.