构建 MariaDB Galera Cluster 分布式数据库集群（二）

MariaDB的安装

构建 MariaDB Galera Cluster之前，首先安装MariaDB，本文使用的版本是10.1

1.环境准备

主机：

MariaDB01（192.168.56.102）
MariaDB02（192.168.56.103）
MariaDB03（192.168.56.104）

OS: centos6.5
MariaDB版本：10.1

yum源设置
Here is your custom MariaDB YUM repository entry for CentOS. Copy and paste it into a file under /etc/yum.repos.d/ (we suggest naming the file MariaDB.repo or something similar). See "Installing MariaDB with yum" for detailed information.
#翻译：这是您CentOS的自定义MariaDB YUM存储库条目。将它复制并粘贴到/etc/yum.repos.d/下的文件（我们建议命名文件MariaDB.repo或类似的东西）。有关详细信息，请参阅“使用yum安装MariaDB”。

vim /etc/yum.repos.d/MariaDB.repo 写入如下内容：

# MariaDB 10.1 CentOS repository list - created -- : UTC

# http://downloads.mariadb.org/mariadb/repositories/

[mariadb]

name = MariaDB

baseurl = http://yum.mariadb.org/10.1/centos6-amd64

gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB

gpgcheck=

然后执行下列命令导入证书并更新repo

# sudo rpm --import https://yum.mariadb.org/RPM-GPG-KEY-MariaDB

# yum repolist

如果你对网络质量充满信心，你现在就可以进入第二步的安装maridb了，但是我强烈建议你用下面的这个方法，因为你可能要反复测试重装个几次，毕竟每次都从官网下载不是一件高效的事儿。

就像上面说的，如果你担心和考虑到网络质量不佳的情况，可下载rpm包后自建yum源
http://downloads.mariadb.com/MariaDB/mariadb-10.1/yum/rhel/mariadb-10.1.19-rhel-6-x86_64-rpms.tar 自建yum源方法可问下度娘
或者访问https://mariadb.com/downloads/maxscale下载最新版本的mariadb（它会自动给你选择最新的mariadb的，由于各版本安装配置差异较大，本文只对mariadb10.1版本负责）
对新版感兴趣的可以测试下maxscale方法：
#install MariaDB MaxScale like this:
#https://mariadb.com/downloads/maxscale
yum install maxscale 或者
RPM-ivh https://downloads.mariadb.com/MaxScale/2.0.3/rhel/6/x86_64/maxscale-2.0.3-1.rhel.6.x86_64.rpm
或者依据官方提供的https://downloads.mariadb.com/MaxScale/x.x.x/rhel/6/x86_64/maxscale-x.x.x-.rhel.6.x86_64.rpm最新版本进行安装

2.安装maridb

以下安装过程来源于官网 https://mariadb.com/kb/en/mariadb-enterprise/mariadb-enterprise-installation-guide/
#Install MariaDB Enterprise Server or MariaDB Enterprise Cluster 10.1 like this:

yum install MariaDB-server MariaDB-client

官网还提供了MariaDB Enterprise Cluster 5.5的安装方法，不是本文的重点，直接跳过。
值得注意的是，如果你要安装5.5版本，则后面的cluster集群的安装配置和10.1版本下是完全不一样的，需要高度注意，避免发生混淆和错误。

3.创建执行用户

# groupadd mariadb

# useradd -g mariadb mariadb

# passwd mariadb

# echo 'mariadb ALL=(ALL) ALL' >> /etc/sudoers
# cd /var/lib
# chown -R mariadb:mariadb mysql

4.启动maridb服务

请根据自身系统版本，选择适合的启动方法启动即可。本文安装环境是在centos6.5下，按照4.3进行启动

4.1：On RHEL and CentOS starting with version 7 using systemd, start MariaDB like this: (通过systemd启动mariadb)
# systemctl start mariadb.service

4.2：or on RHEL and CentOS starting with version 7 using systemd, bootstrap the first node of a MariaDB Enterprise Cluster like this:
# galera_new_cluster

4.3：or on RHEL and CentOS before version 7, such as centos6.5， start MariaDB like this:（在centos6.5上仍然按照启动mysql的方法启动mariadb）

# service mysql start

启动时可能会遇到下列错误：
Starting MySQL.161222 11:28:27 mysqld_safe Logging to '/var/lib/mysql/MariaDB03.err'.
ERROR!
#检查是由于/var/lib/mysql/MariaDB03.err权限的问题，需要执行 su mariadb，在mariadb用户下启动服务

[root@MariaDB03 ~]# cat /var/lib/mysql/MariaDB03.err

 :: mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

-- ::  [Note] /usr/sbin/mysqld (mysqld 10.1.-MariaDB) starting as process  ...

-- ::  [ERROR] mysqld: File '/var/lib/mysql/aria_log_control' not found (Errcode:  "Permission denied")

-- ::  [ERROR] mysqld: Got error 'Can't open file' when trying to use aria control file '/var/lib/mysql/aria_log_control'

-- ::  [ERROR] Plugin 'Aria' init function returned error.

-- ::  [ERROR] Plugin 'Aria' registration as a STORAGE ENGINE failed.

-- ::  [Note] InnoDB: Using mutexes to ref count buffer pool pages

-- ::  [Note] InnoDB: The InnoDB memory heap is disabled

-- ::  [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

-- ::  [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier

-- ::  [Note] InnoDB: Compressed tables use zlib 1.2.

-- ::  [Note] InnoDB: Using Linux native AIO

-- ::  [Note] InnoDB: Using SSE crc32 instructions

-- ::  [Note] InnoDB: Initializing buffer pool, size = 128.0M

-- ::  [Note] InnoDB: Completed initialization of buffer pool

-- ::  [ERROR] InnoDB: ./ibdata1 can't be opened in read-write mode

-- ::  [ERROR] InnoDB: The system tablespace must be writable!

-- ::  [ERROR] Plugin 'InnoDB' init function returned error.

-- ::  [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.

-- ::  [Note] Plugin 'FEEDBACK' is disabled.

-- ::  [ERROR] Could not open mysql.plugin table. Some plugins may be not loaded

-- ::  [ERROR] Unknown/unsupported storage engine: InnoDB

-- ::  [ERROR] Aborting

 :: mysqld_safe mysqld from pid file /var/lib/mysql/MariaDB03.pid en

# su mariadb
$ service mysql start

4.4：or on RHEL and CentOS before version 7, bootstrap the first node of a MariaDB Enterprise Cluster like this:
service mysql bootstrap

5.初始化maridb数据库

在mariadb@MariaDB01 至 mariadb@MariaDB03上分别初始化msyql

[mariadb@MariaDB01 root]# su mariadb

$ sudo mysql_secure_installation

>根据提示进行操作
>由于是测试，密码推荐设置为空，便于后面的操作，正式用的时候再修改密码
>一定要设置不允许root远程访问，这是起码的操守，不要再问为什么了，因为以后也不会再去改它了吧

5.防火墙设置

centos6，root下执行

# iptables -A INPUT -i eth0 -p tcp --dport  -j ACCEPT

# iptables -A INPUT -i eth0 -p tcp --dport  -j ACCEPT

如果在centos7下，诸如这样执行：

# firewall-cmd --add-port=/tcp #暂时生效，重启后失效

# firewall-cmd --permanent --add-port=/tcp #永久生效

正式环境务必要配置防火墙的，尤其对于研发的人来说，一定要重视这个问题
如测试用，可关闭防火墙，忽略此配置即可

6.mysql管理和监控工具

MySQL免费性能监控工具-MONyog 分linux和windows版
SQLyog数据库管理只有windows版
上面的工具说实话我没用过，我更习惯用nginx/zabbix进行监控，用navicat进行管理

7.使用

安装完了，简单测试下吧

[mariadb@MariaDB01 my.cnf.d]$ mysql -uroot -p

Enter password:

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is

Server version: 10.1.-MariaDB MariaDB Server

Copyright (c) , , Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

#看看集群的状态如何

MariaDB [(none)]> show status like 'wsrep%';

+--------------------------+----------------------+

| Variable_name            | Value                |

+--------------------------+----------------------+

| wsrep_cluster_conf_id    |  |

| wsrep_cluster_size       |                     |

| wsrep_cluster_state_uuid |                      |

| wsrep_cluster_status     | Disconnected         |

| wsrep_connected          | OFF                  |

| wsrep_local_bf_aborts    |                     |

| wsrep_local_index        |  |

| wsrep_provider_name      |                      |

| wsrep_provider_vendor    |                      |

| wsrep_provider_version   |                      |

| wsrep_ready              | OFF                  |

| wsrep_thread_count       |                     |

+----------------------

MariaDB [(none)]> show variables like 'wsrep_cluster_address';

+-----------------------+------------------------------------------------------+

| Variable_name         | Value                                                |

+-----------------------+------------------------------------------------------+

| wsrep_cluster_address | gcomm://192.168.56.102,192.168.56.103,192.168.56.104 |  #这个展示是已经配置过集群的，初始安装的这里显示的应该是空，不要被误导啊！

+-----------------------+------------------------------------------------------+

 row in set (0.00 sec)

现在还只是个MariaDB10.1的环境，要完成MariaDB Galera Cluster请继续看下一章内容

-本章完-

2017-02-24