Chapter 18 MySQL NDB Cluster 7.3 and NDB Cluster 7.4

This chapter contains information about MySQL NDB Cluster, which is a high-availability, high-redundancy version of MySQL adapted for the distributed computing environment. Recent releases of NDB Cluster 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 7.5, now available as a General Availability (GA) release beginning with version 7.5.4, incorporates version 7.5 of the NDB storage engine. Previous GA releases still available for production, NDB Cluster 7.3 and NDB Cluster 7.4, incorporate NDB versions 7.3 and 7.4, respectively.

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 5.6.35-ndb-7.3.17 as well as NDB Cluster 7.4 releases through 5.6.35-ndb-7.4.15. Currently, NDB Cluster 7.5 is available as a General Availability release, and recommended for new deployments. The NDB Cluster 7.4 and NDB Cluster 7.3 release series 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 7.5 (see MySQL NDB Cluster 7.5). For more information about NDB Cluster 7.2, see MySQL NDB Cluster 7.2.

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 http://www.mysql.com/support/supportedplatforms/cluster.html.

Availability.  NDB Cluster binary and source packages are available for supported platforms from http://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-mysql_server_version-ndb-ndb_engine_version

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: 5.6.35-ndb-7.4.15 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> SELECT VERSION()\G
*************************** 1. row ***************************
VERSION(): 5.6.35-ndb-7.4.15
1 row in set (0.00 sec)

This version string is also displayed in the output of the SHOW command in the ndb_mgm client:

ndb_mgm> SHOW
Connected to Management Server at: localhost:1186
Cluster Configuration
---------------------
[ndbd(NDB)]     2 node(s)
id=1    @10.0.10.6  (5.6.35-ndb-7.4.15, Nodegroup: 0, *)
id=2    @10.0.10.8  (5.6.35-ndb-7.4.15, Nodegroup: 0)

[ndb_mgmd(MGM)] 1 node(s)
id=3    @10.0.10.2  (5.6.35-ndb-7.4.15)

[mysqld(API)]   2 node(s)
id=4    @10.0.10.10  (5.6.35-ndb-7.4.15)
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 release) is mysql-5.6.23-ndb-7.4.4. From this we can determine the following:

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 string: mysql-5.6.22-ndb-7.4.3).

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 18.1.6, “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, MyISAM or 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 Cluster.

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 Bazaar and building them yourself, see Section 2.9.3, “Installing MySQL Using a Development Source Tree”.

Currently, NDB Cluster 7.3 and NDB Cluster 7.4 releases are Generally Available (GA). We recommend that new deployments use NDB Cluster 7.4. NDB Cluster 7.1 and earlier versions are no longer in active development. For an overview of major features added in NDB Cluster 7.4, see Section 18.1.4.2, “What is New in NDB Cluster 7.4”. For similar information about NDB Cluster 7.3, see Section 18.1.4.1, “What is New in NDB Cluster 7.3”. For an overview of major features added in past NDB Cluster releases, see What is New in NDB Cluster in NDB Cluster 7.2. NDB Cluster 7.5 is also available as a Developer Preview for testing of new features; for more information, see MySQL NDB Cluster 7.5.

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 Web site at http://www.mysql.com/products/cluster/.

Additional Resources.  More information about NDB Cluster can be found in the following places: