MySQL集群安裝與配置
MySQL Cluster 是 MySQL 適合于分布式計算環境的高實用、高冗余版本。它采用了NDB Cluster 存儲引擎，允許在1個 Cluster 中運行多個MySQL服務器。MySQL Cluster 能夠使用多種故障切換和負載平衡選項配置NDB存儲引擎，但在 Cluster 級別上的存儲引擎上做這個最簡單。下面我們簡單介紹MySQL Cluster如何安裝與配置。
基本設定
管理(MGM)節點:192.168.0.111
MySQL服務器(SQL)節點:192.168.0.110
數據(NDBD)節點"A":192.168.0.112
數據(NDBD)節點"B":192.168.0.113
一、mysql集群安裝
mysql的集群安裝可以有三種方式，一是直接下載二進制使用，二是使用rpm安裝，三是源碼編譯。我們這里使用第一種安裝。
1、每個節點做相同的操作
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：這里下載的是32位的二進制包，如果你的系統是64位，需要下載64位的包。
2、存儲節點和SQL節點安裝
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、節點配置
1、配置存儲節點和SQL節點
vi /etc/my.cnf
類似于：
# 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、配置管理節點
mkdir /var/lib/mysql-cluster
cd /var/lib/mysql-cluster
vi config.ini
config.ini文件應類似于：
# 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、首次啟動節點
1、啟動管理節點
/usr/local/mysql/bin/ndb_mgmd --configdir=/var/lib/mysql-cluster -f /var/lib/mysql-cluster/config.ini
2、啟動數據節點
首次啟動需要--initial參數初始化，下一次啟動就不需要了。
/usr/local/mysql/bin/ndbd --initial
3、啟動SQL節點
/usr/local/mysql/bin/mysqld_safe &
4、檢查狀態
如果一切正常，執行命令 /usr/local/mysql/bin/ndb_mgm -e show應該會輸出類似信息：
[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、測試服務是否正常
在SQL節點上執行如下數據庫操作：
/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;
如果出現：
+----+
| id |
+----+
| 1 |
| 2 |
| 4 |
| 3 |
+----+
則表示工作正常。
五、安全關閉和重啟
1、關閉mysql集群，可在管理節點在執行如下命令：
/usr/local/mysql/bin/ndb_mgm -e shutdown
2、重啟管理節點
/usr/local/mysql/bin/ndb_mgmd --configdir=/var/lib/mysql-cluster -f /var/lib/mysql-cluster/config.ini
3、重啟數據節點
/usr/local/mysql/bin/ndbd