MySQL集群安装与配置
MySQL Cluster 是 MySQL 适合于分布式计算环境的高实用、高冗余版本。它采用了NDB Cluster 存储引擎，允许在1个 Cluster 中运行多个MySQL服务器。MySQL Cluster 能够使用多种故障切换和负载平衡选项配置NDB存储引擎，但在 Cluster 级别上的存储引擎上做这个最简单。下面我们简单介绍MySQL Cluster如何安装与配置。
基本设定
管理(MGM)节点:192.168.0.111
MySQL服务器(SQL)节点:192.168.0.110
数据(NDBD)节点"A":192.168.0.112
数据(NDBD)节点"B":192.168.0.113
一、mysql集群安装
mysql的集群安装可以有三种方式，一是直接下载二进制使用，二是使用rpm安装，三是源码编译。我们这里使用第一种安装。
1、每个节点做相同的操作
cd /tmp
wget http://cdn.mysql.com/Downloads/MySQL-Cluster-7.2/mysql-cluster-gpl-7.2.8-linux2.6-i686.tar.gz
tar xzf mysql-cluster-gpl-7.2.8-linux2.6-i686.tar.gz
mv mysql-cluster-gpl-7.2.8-linux2.6-i686 /usr/local/mysql
注意：这里下载的是32位的二进制包，如果你的系统是64位，需要下载64位的包。
2、存储节点和SQL节点安装
groupadd mysql
useradd -g mysql mysql
/usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --user=mysql
chown -R root /usr/local/mysql
chown -R mysql /usr/local/mysql/data
chgrp -R mysql /usr/local/mysql
cp /usr/local/mysql/support-files/my-medium.cnf /etc/my.cnf
二、节点配置
1、配置存储节点和SQL节点
vi /etc/my.cnf
类似于：
# Options for mysqld process:
[MYSQLD]
ndbcluster # run NDB engine
ndb-connectstring=198.168.0.111 # location of MGM node
# Options for ndbd process:
[MYSQL_CLUSTER]
ndb-connectstring=198.168.0.111 # location of MGM node
2、配置管理节点
mkdir /var/lib/mysql-cluster
cd /var/lib/mysql-cluster
vi config.ini
config.ini文件应类似于：
# Options affecting ndbd processes on all data nodes:
[NDBD DEFAULT]
NoOfReplicas=2 # Number of replicas
DataMemory=80M # How much memory to allocate for data storage
IndexMemory=18M # How much memory to allocate for index storage
# For DataMemory and IndexMemory, we have used the
# default values. Since the "world" database takes up
# only about 500KB, this should be more than enough for
# this example Cluster setup.
# TCP/IP options:
[TCP DEFAULT]
portnumber=2202 # This the default; however, you can use any
# port that is free for all the hosts in cluster
# Note: It is recommended beginning with MySQL 5.0 that
# you do not specify the portnumber at all and simply allow
# the default value to be used instead
# Management process options:
[NDB_MGMD]
hostname=198.168.0.111 # Hostname or IP address of MGM node
datadir=/var/lib/mysql-cluster # Directory for MGM node logfiles
# Options for data node "A":
[NDBD]
# (one [NDBD] section per data node)
hostname=198.168.0.112 # Hostname or IP address
datadir=/usr/local/mysql/data # Directory for this data node's datafiles
# Options for data node "B":
[NDBD]
hostname=198.168.0.113 # Hostname or IP address
datadir=/usr/local/mysql/data # Directory for this data node's datafiles
# SQL node options:
[MYSQLD]
hostname=198.168.0.110 # Hostname or IP address
# (additional mysqld connections can be
# specified for this node for various
# purposes such as running ndb_restore)
三、首次启动节点
1、启动管理节点
/usr/local/mysql/bin/ndb_mgmd --configdir=/var/lib/mysql-cluster -f /var/lib/mysql-cluster/config.ini
2、启动数据节点
首次启动需要--initial参数初始化，下一次启动就不需要了。
/usr/local/mysql/bin/ndbd --initial
3、启动SQL节点
/usr/local/mysql/bin/mysqld_safe &
4、检查状态
如果一切正常，执行命令 /usr/local/mysql/bin/ndb_mgm -e show应该会输出类似信息：
[root@localhost mysql-cluster]# /usr/local/mysql/bin/ndb_mgm -e show
Connected to Management Server at: localhost:1186
Cluster Configuration
---------------------
[ndbd(NDB)] 2 node(s)
id=2 @192.168.0.112 (mysql-5.5.27 ndb-7.2.8, Nodegroup: 0, Master)
id=3 @192.168.0.113 (mysql-5.5.27 ndb-7.2.8, Nodegroup: 0)
[ndb_mgmd(MGM)] 1 node(s)
id=1 @192.168.0.111 (mysql-5.5.27 ndb-7.2.8)
[mysqld(API)] 1 node(s)
id=4 @192.168.0.110 (mysql-5.5.27 ndb-7.2.8)
四、测试服务是否正常
在SQL节点上执行如下数据库操作：
/usr/local/mysql/bin/mysql -uroot -p
mysql> create database clusterdb;use clusterdb;
mysql> create table simples (id int not null primary key) engine=ndb;
mysql> insert into simples values (1),(2),(3),(4);
mysql> select * from simples;
如果出现：
+----+
| id |
+----+
| 1 |
| 2 |
| 4 |
| 3 |
+----+
则表示工作正常。
五、安全关闭和重启
1、关闭mysql集群，可在管理节点在执行如下命令：
/usr/local/mysql/bin/ndb_mgm -e shutdown
2、重启管理节点
/usr/local/mysql/bin/ndb_mgmd --configdir=/var/lib/mysql-cluster -f /var/lib/mysql-cluster/config.ini
3、重启数据节点
/usr/local/mysql/bin/ndbd