centos7下部署mariadb+galera数据库高可用集群，mariadbgalera
环境准备：
centos7；关闭selinux和firewalld；hosts文件解析；时间同步；root互信；三节点、环境部署：
设置mariadb的yum源并安装（所有节点都要）(下载包的时候会很慢。。。。。)
vi /etc/yum.repos.d/mariadb.repo
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.1/centos7-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1
enabled=0
yum --enablerepo=mariadb -y install MariaDB-server galera
配置第一个 节点（172.16.12.91）
vi /etc/my.cnf.d/server.cnf
[galera]
# Mandatory settings
wsrep_on=ON
wsrep_provider=/usr/lib64/galera/libgalera_smm.so
wsrep_cluster_address=“gcomm://172.16.12.91,172.16.12.92,172.16.12.93”
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
bind-address=0.0.0.0
# add follows
# cluster name
wsrep_cluster_name="MariaDB_Cluster"
# own IP address（当前节点的IP）
wsrep_node_address="172.16.12.91"
# replication provider
wsrep_sst_method=rsync
启动集群：/bin/galera_new_cluster
设置root用户密码：mysql_secure_installation
配置第二个 节点(172.16.12.92)
vi /etc/my.cnf.d/server.cnf
[galera]
# Mandatory settings
wsrep_on=ON
wsrep_provider=/usr/lib64/galera/libgalera_smm.so
# specify all nodes in cluster
wsrep_cluster_address="gcomm://172.16.12.91,172.16.12.92,172.16.12.93 "
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
bind-address=0.0.0.0
# add follows
# cluster name
wsrep_cluster_name="MariaDB_Cluster"
# own IP address（当前节点的IP）
wsrep_node_address="172.16.12.92"
# replication provider
wsrep_sst_method=rsync
启动集群节点：systemctl start mariadb
配置第三个 节点(172.16.12.93)
vi /etc/my.cnf.d/server.cnf
[galera]
# Mandatory settings
wsrep_on=ON
wsrep_provider=/usr/lib64/galera/libgalera_smm.so
# specify all nodes in cluster(所有节点的IP，这里只有2台机器)
wsrep_cluster_address="gcomm://172.16.12.91,172.16.12.92,172.16.12.93 "
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
bind-address=0.0.0.0
# add follows
# cluster name
wsrep_cluster_name="MariaDB_Cluster"
# own IP address（当前节点的IP）
wsrep_node_address="172.16.12.93"
# replication provider
wsrep_sst_method=rsync
启动集群节点：systemctl start mariadb
注：当集群宕机时，运行了/bin/galera_new_cluster命令的节点先启动