Galera Cluster for MySQL

Posted 2020-10-17 答案

MySQL Galera介绍

主要功能:

• 同步复制
• 真正的multi-master，即所有节点可以同时读写数据库
• 自动的节点成员控制，失效节点自动被清除
• 新节点加入数据自动复制
• 真正的并行复制，行级
• 用户可以直接连接集群，使用感受上与mysql完全一致

优势:

• 因为是多主，所以不存在Slave lag(延迟)
• 不存在丢失交易的情况
• 同时具有读和写的扩展能力
• 更小的客户端延迟
• 节点间数据是同步的,而Master/Slave模式是异步的,不同slave上的binlog可能是不同的

 

环境

 IP 地址         主机名         描述
10.0.0.10       node1       第一个启动
10.0.0.11       node2
10.0.0.12       node3

版本信息

[[email protected] ~]#  cat /etc/redhat-release
CentOS Linux release 7.1.1503 (Core) 
[[email protected] ~]# uname -a
Linux node2 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 11:36:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

关闭防火墙和SElinux

[[email protected] ~]# systemctl stop firewalld.service
[[email protected] ~]# setenforce 0

清除原有Mysql

[[email protected] ~]# yum erase mysql mysql-devel mysql-libs -y
[[email protected] ~]# rpm -qa |grep mysql

组件下载地址

http://releases.galeracluster.com/mysql-wsrep-5.6/centos/7/x86_64/
http://releases.galeracluster.com/galera-3/centos/7/x86_64/

安装组件（yum 安装，依次安装了,如果失败，等其他安装包安装好以后，重新安装一遍）

[[email protected] ~]# yum install -y http://releases.galeracluster.com/mysql-wsrep-5.6/centos/7/x86_64/mysql-wsrep-client-5.6-5.6.38-25.21.el7.x86_64.rpm
[[email protected] ~]# yum install -y http://releases.galeracluster.com/mysql-wsrep-5.6/centos/7/x86_64/mysql-wsrep-devel-5.6-5.6.38-25.21.el7.x86_64.rpm
[[email protected] ~]# yum install -y http://releases.galeracluster.com/mysql-wsrep-5.6/centos/7/x86_64/mysql-wsrep-shared-5.6-5.6.38-25.21.el7.x86_64.rpm
[[email protected] ~]# yum install -y http://releases.galeracluster.com/mysql-wsrep-5.6/centos/7/x86_64/mysql-wsrep-test-5.6-5.6.38-25.21.el7.x86_64.rpm
[[email protected] ~]# yum install -y http://releases.galeracluster.com/galera-3/centos/7/x86_64/galera-3-25.3.22-2.el7.x86_64.rpm
[[email protected] ~]# yum install -y http://releases.galeracluster.com/mysql-wsrep-5.6/centos/7/x86_64/mysql-wsrep-server-5.6-5.6.38-25.21.el7.x86_64.rpm

mysql 首次启动

[[email protected] ~]# service mysql start --skip-grant-tables

输入 mysql 登录，添加用户名、密码和对应数据库的用户名、密码权限

mysql> use mysql;
mysql> update user set password=PASSWORD("123456") where USER="root"
mysql> quit

重启数据库

[[email protected] ~]# service mysql restart

重启mysql服务，使用创建的用户名和密码登录.再次进入的时候回提示你设置密码

 mysql> SET PASSWORD=PASSWORD("123456")

 给对应需要访问MySQL的用户名和密码进行授权，如果没有授权，是无法远程连接MySQL的（两条密令二选一）

授权指定端口用户连接mysql数据库的命令
mysql>GRANT ALL PRIVILEGES ON *.* TO ‘root‘@‘10.0.0.10‘ IDENTIFIED BY ‘123456‘ WITH    GRANT OPTION;

授权无端口限制的用户登录mysql数据库
mysql>GRANT ALL PRIVILEGES ON *.* TO ‘root‘@‘%‘ IDENTIFIED BY ‘123456‘ WITH GRANT OPTION;　　

创建同步账号

mysql> grant all on *.* to ‘wsrep‘@‘%‘ identified by ‘nx111111‘;
mysql> quit

设置Mysql为开机启动

[[email protected] ~]# chkconfig mysql on

去掉Postfix,这个可能跟MySQL配置有冲突

[[email protected] ~]# yum remove postfix -y

关闭Mysql

[[email protected] ~]# service mysql stop

配置文件

[[email protected] ~]# vim /etc/my.cnf 
!includedir /etc/my.cnf.d/

拷贝swrep.conf 文件到/etc/my.cnf.d/下

[[email protected] ~]# cp -r /usr/share/doc/mysql-wsrep-server-5.6-5.6.38/wsrep.cnf /etc/my.cnf.d/

将以下配置替原有配置

vim /etc/my.cnf.d/wsrep.conf

[mysqld]
server_id = 10    # 每个节点都不一样，分别是 10、11、12
default_storage_engine = InnoDB
datadir =/var/lib/mysql/
binlog_format = ROW
log-bin = mysql-bin
log-slave-updates = 1              
innodb_autoinc_lock_mode = 2
lower_case_table_names = 1   # 修改这个配置必须重启
log_bin_trust_function_creators = 1

wsrep_provider = /usr/lib64/galera-3/libgalera_smm.so
wsrep_sst_auth = wsrep:nx111111
wsrep_sst_method = xtrabackup
wsrep_cluster_name = ‘nx_wsrep‘  # 集群名，一定要一致。
wsrep_node_name = node1  #本节点主机名
wsrep_cluster_address = gcomm://10.0.0.11,10.0.0.12  # 其它节点 IP
wsrep_node_address = 10.0.0.10  # 本节点 IP
wsrep_sst_donor=node2,node3,  # 其它节点的名称
wsrep_sst_method = rsync
wsrep_slave_threads=8

innodb_buffer_pool_size=10737418240
innodb_log_file_size=134217728
innodb_flush_log_at_trx_commit=2

#innodb_buffer_pool_dump_at_shutdown=1
#innodb_buffer_pool_load_at_startup=1
#innodb_log_file_buffer_size=16777216
skip-name-resolve

[client]
user = wsrep
password = nx111111

启动 mysql-wsrep

集群中的第一个节点，以空地址启动

[[email protected] ~]# mysqld_safe --wsrep_cluster_address=gcomm:// >/dev/null &

其它节点，启动方式

[[email protected] ~]# mysqld_safe > /dev/null &

查看集群状态

确认MySQL的3306端口和wsrep的4567端口处于监听状态

[[email protected] ~]# netstat -tulpn | grep -e 4567 -e 3306
tcp        0      0 0.0.0.0:4567            0.0.0.0:*               LISTEN      5036/mysqld         
tcp6       0      0 :::3306                 :::*                    LISTEN      5036/mysqld

集群功能是否开启

mysql> show status like ‘wsrep_ready‘; 
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wsrep_ready   | ON    |
+---------------+-------+
1 row in set (0.00 sec)

集群ID号

mysql> SHOW  GLOBAL  STATUS  LIKE  ‘wsrep_cluster_state_uuid‘ ;
+--------------------------+--------------------------------------+
| Variable_name            | Value                                |
+--------------------------+--------------------------------------+
| wsrep_cluster_state_uuid | 176a8d84-e0ba-11e7-9e7b-d7b3a39130ff |
+--------------------------+--------------------------------------+
1 row in set (0.00 sec)

集群中的节点数量

mysql> SHOW  GLOBAL  STATUS  LIKE  ‘wsrep_cluster_size‘ ;
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| wsrep_cluster_size | 3     |
+--------------------+-------+
1 row in set (0.00 sec)

集群（其他）节点地址

mysql> show variables like ‘wsrep_cluster_address‘;
+-----------------------+----------+
| Variable_name         | Value    |
+-----------------------+----------+
| wsrep_cluster_address | gcomm:// |
+-----------------------+----------+
1 row in set (0.00 sec)

参考

http://blog.csdn.net/yangchuan_csdn91/article/details/52689981?locationNum=2