一、简述HA高可用集群
高可用集群就是当集群中的一个节点发生各种软硬件及人为故障时，集群中的其他节点能够自动接管故障节点的资源并向外提供服务。以实现减少业务中断时间，为用户提供更可靠，更高效的服务。
二、基于nfs实现mysql的高可用集群配置
环境准备接上文 heartbeat-gui部署
实验环境：
nfs server准备
1、在nfs server准备LVM存储空间[root@node3 ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x61284c6a.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (1-1305, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305): +10G
Value out of range.
Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305): +5G
Command (m for help): t
Selected partition 3
Hex code (type L to list codes): 8e
Changed system type of partition 3 to 8e (Linux LVM)
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@node3 ~]# partx -a /dev/sdb
[root@node3 ~]# pvcreate /dev/sdb3
Physical volume "/dev/sdb3" successfully created
[root@node3 ~]# vgcreate myvg /dev/sdb3
Volume group "myvg" successfully created
[root@node3 ~]# lvcreate -L 5G -n mydata myvg
Logical volume "mydata" created.
[root@node3 ~]# mke2fs -t ext4 /dev/myvg/mydata
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
327680 inodes, 1310720 blocks
65536 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1342177280
40 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
2、开机自动挂载，并nfs导出
[root@node3 ~]# mkdir /mydata
[root@node3 ~]# vim /etc/fstab
/dev/myvg/mydata /mydata ext4 defaults 0 0
[root@node3 ~]# mount -a
[root@node3 ~]# mount | grep /mydata
/dev/mapper/myvg-mydata on /mydata type ext4 (rw)
[root@node3 ~]# vim /etc/exports
/mydata 192.168.0.0/24(rw,no_root_squash)
#共享给192.168.0.0/24网段，可读可写，允许root用户登录便于初始化，配置结束可取消root用户登录
3、导出nfs共享目录
#创建mysql用户，指明uid，gid。各节点的mysql用户uid，gid一致。
[root@node3 ~]# groupadd -r -g 306 mysql
[root@node3 ~]# useradd -r -g 306 -u 306 mysql
#创建共享目录，并修改属主属组。
[root@node3 ~]# mkdir /mydata/data
[root@node3 ~]# chown -R mysql.mysql /mydata/data
#导出nfs共享目录
[root@node3 ~]# exportfs -arv
exporting 192.168.0.0/24:/mydata
各节点准备mysql，并测试nfs。以下步骤，各节点一致。
node1配置
[root@node1 ~]# mkdir /mydata[root@node1 ~]# showmount -e 192.168.0.20Export list for 192.168.0.20:/mydata 192.168.0.0/24[root@node1 ~]# mount -t nfs 192.168.0.20:/mydata /mydata[root@node1 ~]# mount | grep /mydata192.168.0.20:/mydata on /mydata type nfs (rw,vers=4,addr=192.168.0.20,clientaddr=192.168.0.15)[root@node1 ~]# groupadd -r -g 306 mysql[root@node1 ~]# useradd -r -g 306 -u 306 mysql#验证mysql用户是否拥有共享目录权限[root@node1 ~]# su - mysqlsu: warning: cannot change directory to /home/mysql: No such file or directory-bash-4.1$ -bash-4.1$ -bash-4.1$ cd /mydata/data-bash-4.1$ touch node1.txt-bash-4.1$ lsnode1.txt-bash-4.1$ rm node1.txt -bash-4.1$ exitlogout#在nfs server端验证[root@node3 ~]# cd /mydata/data[root@node3 data]# lltotal 0-rw-rw-r--. 1 mysql mysql 0 Nov 19 19:59 node2.txt#验证root用户对目录是否有权限[root@node2 ~]# touch /mydata/data/node.txt[root@node2 ~]# ll /mydata/datatotal 0-rw-r--r--. 1 root root 0 Nov 19 20:02 node.txt#安装mariadb[root@node1 ~]# tar xf mariadb-5.5.46-linux-x86_64.tar.gz -C /usr/local[root@node1 ~]# cd /usr/local[root@node1 local]# ln -sv mariadb-5.5.46-linux-x86_64 mysql`mysql' -> `mariadb-5.5.46-linux-x86_64'[root@node1 local]# cd mysql/[root@node1 mysql]# chown -R root.mysql ./*#初始化mysql至nfs，此步骤只需一个节点操作即可，本文node1执行，那么node2就不需要执行#初始化操作后，可以将nfs server的共享选项中的no_root_squash移除了[root@node1 mysql]# ./scripts/mysql_install_db --datadir=/mydata/data/ --user=mysql#nfs server验证[root@node3 data]# lsaria_log.00000001 aria_log_control mysql performance_schema test#为mysql节点准备配置文件[root@node1 mysql]# mkdir /etc/mysql[root@node1 mysql]# cp support-files/my-large.cnf /etc/mysql/my.cnf#编辑配置文件，加入以下三行[root@node1 mysql]# vim /etc/mysql/my.cnfdatadir = /mydata/datainnodb_file_per_table = onskip_name_resolve = on#为mysql节点准备服务脚本，并禁止mysqld开机自启[root@node1 mysql]# cp support-files/mysql.server /etc/rc.d/init.d/mysqld[root@node1 mysql]# chkconfig --add mysqld[root@node1 mysql]# chkconfig mysqld off#启动mysql，创建mydb数据库[root@node1 mysql]# service mysqld start[root@node1 mysql]# /usr/local/mysql/bin/mysqlWelcome to the MariaDB monitor. Commands end with ; or \g.Your MariaDB connection id is 3Server version: 5.5.46-MariaDB-log MariaDB ServerCopyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.MariaDB [(none)]> CREATE DATABASE mydb;Query OK, 1 row affected (0.03 sec)MariaDB [(none)]> exitBye[root@node1 mysql]# service mysqld stop
node2配置
[root@node2 ~]# tar xf mariadb-5.5.46-linux-x86_64.tar.gz -C /usr/local[root@node2 ~]# cd /usr/local/[root@node2 local]# ln -sv mariadb-5.5.46-linux-x86_64 mysql`mysql' -> `mariadb-5.5.46-linux-x86_64'[root@node2 local]# cd mysql/[root@node2 mysql]# chown root.mysql ./*#将node1的mysql配置文件复制给node2[root@node1 mysql]# scp /etc/mysql/my.cnf node2:/etc/mysql/#准备服务脚本，并禁止开机自启[root@node2 mysql]# cp support-files/mysql.server /etc/rc.d/init.d/mysqld[root@node2 mysql]# chkconfig --add mysqld[root@node2 mysql]# chkconfig mysqld off#启动服务并查看共享数据库[root@node2 mysql]# service mysqld start[root@node2 mysql]# /usr/local/mysql/bin/mysqlWelcome to the MariaDB monitor. Commands end with ; or \g.Your MariaDB connection id is 2Server version: 5.5.46-MariaDB-log MariaDB ServerCopyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.MariaDB [(none)]> SHOW DATABASES;+--------------------+| Database |+--------------------+| information_schema || mydb || mysql || performance_schema || test |+--------------------+5 rows in set (0.02 sec)MariaDB [(none)]> EXITBye#授权root用户远程访问mysql[root@node2 ~]# /usr/local/mysql/bin/mysqlWelcome to the MariaDB monitor. Commands end with ; or \g.Your MariaDB connection id is 3Server version: 5.5.46-MariaDB-log MariaDB ServerCopyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.MariaDB [(none)]> grant all on *.* to 'root'@'192.168.%.%' identified by '123456';Query OK, 0 rows affected (0.06 sec)MariaDB [(none)]> flush privileges;Query OK, 0 rows affected (0.01 sec)[root@node2 mysql]# service mysqld stop
在node1和node2卸载共享目录
[root@node1 mysql]# umount /mydata
三、在heartbeat-gui界面配置
1、添加组资源，以及ip资源
2、添加共享文件系统资源
3、添加mysql-server资源
注意：定义的次序就是启动的次序。
本文出自 “linux启航” 博客，请务必保留此出处http://jiayimeng.blog.51cto.com/10604001/1874668