配置NDB集群
作为NDB集群一部分的MySQL服务器与普通的（非集群的）MySQL服务器有一个主要的区别，那就是它使用了NDB存储引擎。这个引擎有时也被称为 NDBCLUSTER，不过NDB是首选。
为避免不必要的资源分配，服务器默认配置为关闭NDB存储引擎。要启用NDB，必须修改服务器的my.cnf配置文件，或者使用–ndbcluster选项启 动服务器。这个MySQL服务器是集群的一部分，因此它也必须知道如何访问管理节点以获取集群配置数据。默认行为是在localhost上查找管理节点。但是， 如果您需要指定它的位置在其他地方，可以在my.cnf中完成，或者使用mysql客户端。在使用NDB存储引擎之前，必须保证至少有一个管理节点和 任意一个数据节点处于正常运行状态。
首先，以系统root用户执行如下命令，创建一个配置目录/var/lib/mysql-cluster，例如:
shell> mkdir /var/lib/mysql-cluster
在该目录下，创建一个名为config.ini的文件，该文件包含以下信息。根据系统需要，为HostName和DataDir替换适当的值。
# file "config.ini" - showing minimal setup consisting of 1 data node, # 1 management server, and 3 MySQL servers. # The empty default sections are not required, and are shown only for # the sake of completeness. # Data nodes must provide a hostname but MySQL Servers are not required # to do so. # If you don't know the hostname for your machine, use localhost. # The DataDir parameter also has a default value, but it is recommended to # set it explicitly. # Note: [db], [api], and [mgm] are aliases for [ndbd], [mysqld], and [ndb_mgmd], # respectively. [db] is deprecated and should not be used in new installations. [ndbd default] NoOfReplicas= 1 [mysqld default] [ndb_mgmd default] [tcp default] [ndb_mgmd] HostName= myhost.example.com [ndbd] HostName= myhost.example.com DataDir= /var/lib/mysql-cluster [mysqld] [mysqld] [mysqld]
现在可以启动ndb_mgmd管理服务器。默认情况下，它尝试读取当前工作目录下的config.ini文件，因此进入文件所在的目录，然后调用ndb_mgmd ：
shell> cd /var/lib/mysql-cluster shell> ndb_mgmd
然后执行命令ndbd启动单个数据节点。
shell> ndbd
默认情况下，ndbd在端口1186的localhost上查找管理服务器。
如果您从二进制tarball安装MySQL，则需要显式指定ndb_mgmd和ndbd服务器的路径。（通常，这些将在/ usr/local/mysql/bin中找到。
最后，将位置更改为MySQL数据目录（通常为/var/lib/mysql或/usr/local/mysql/ data），并确保my.cnf文件包含启用NDB存储引擎所需的选项 ：
[mysqld] ndbcluster
现在你可以像往常一样启动MySQL服务器了：
shell> mysqld_safe --user=mysql &
或者
shell>service mysql.server start
等待片刻，确保MySQL服务器正常运行。如果您看到mysql结束的通知，请检查服务器的.err文件以找出出错的地方。
如果到目前为止一切顺利，那么现在可以开始使用集群了。连接到服务器并验证开启NDBCLUSTER存储引擎：
[root@mysqld /]# mysql -u root -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.48-ndb-7.5.36-cluster-gpl MySQL Cluster Community Server (GPL)
Copyright (c) 2000, 2024, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> SHOW ENGINES\G
*************************** 1. row ***************************
Engine: ndbcluster
Support: YES
Comment: Clustered, fault-tolerant tables
Transactions: YES
XA: NO
Savepoints: NO
*************************** 2. row ***************************
Engine: CSV
Support: YES
Comment: CSV storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 3. row ***************************
Engine: InnoDB
Support: DEFAULT
Comment: Supports transactions, row-level locking, and foreign keys
Transactions: YES
XA: YES
Savepoints: YES
*************************** 4. row ***************************
Engine: ndbinfo
Support: YES
Comment: MySQL Cluster system information storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 5. row ***************************
Engine: MyISAM
Support: YES
Comment: MyISAM storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 6. row ***************************
Engine: PERFORMANCE_SCHEMA
Support: YES
Comment: Performance Schema
Transactions: NO
XA: NO
Savepoints: NO
*************************** 7. row ***************************
Engine: ARCHIVE
Support: YES
Comment: Archive storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 8. row ***************************
Engine: MRG_MYISAM
Support: YES
Comment: Collection of identical MyISAM tables
Transactions: NO
XA: NO
Savepoints: NO
*************************** 9. row ***************************
Engine: FEDERATED
Support: NO
Comment: Federated MySQL storage engine
Transactions: NULL
XA: NULL
Savepoints: NULL
*************************** 10. row ***************************
Engine: BLACKHOLE
Support: YES
Comment: /dev/null storage engine (anything you write to it disappears)
Transactions: NO
XA: NO
Savepoints: NO
*************************** 11. row ***************************
Engine: MEMORY
Support: YES
Comment: Hash based, stored in memory, useful for temporary tables
Transactions: NO
XA: NO
Savepoints: NO
11 rows in set (0.00 sec)
前面示例输出中显示的行号可能与系统中显示的行号不同，这取决于服务器的配置方式。
尝试创建一个NDBCLUSTER表：
[root@mysqld /]# mysql -u root -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.48-ndb-7.5.36-cluster-gpl MySQL Cluster Community Server (GPL)
Copyright (c) 2000, 2024, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> use jycs
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> CREATE TABLE ctest (i INT) ENGINE=NDBCLUSTER;
Query OK, 0 rows affected (0.19 sec)
mysql> SHOW CREATE TABLE ctest \G
*************************** 1. row ***************************
Table: ctest
Create Table: CREATE TABLE `ctest` (
`i` int(11) DEFAULT NULL
) ENGINE=ndbcluster DEFAULT CHARSET=latin1
1 row in set (0.01 sec)
mysql>
要检查节点是否正确设置，请启动管理客户端：
[root@mgmd /]# ndb_mgm -- NDB Cluster -- Management Client --
在管理客户端中使用SHOW命令获取集群状态报告：
ndb_mgm> show Cluster Configuration --------------------- [ndbd(NDB)] 2 node(s) id=2 @10.138.130.234 (mysql-5.7.48 ndb-7.5.36, Nodegroup: 0, *) id=3 @10.138.130.235 (mysql-5.7.48 ndb-7.5.36, Nodegroup: 0) [ndb_mgmd(MGM)] 1 node(s) id=1 @10.138.130.232 (mysql-5.7.48 ndb-7.5.36) [mysqld(API)] 1 node(s) id=4 @10.138.130.233 (mysql-5.7.48 ndb-7.5.36)
至此，你已经成功设置好了一个可以工作的NDB集群。现在，你可以使用ENGINE=NDBCLUSTER或别名ENGINE=NDB创建的表在集群中存储数据。