尽可能的控制pxc集群的规模，pxc集群节点越多，数据同步的速度就越慢
所有pxc节点的硬件配置最好相同，pxc集群数据同步的速度取决于配置最低的节点
Pxc集群只支持innodb引擎
安装pxc集群
第一个集群，作为mycat的第一个分片
安装前的准备，因为centos默认安装了mariadb-libs，要删除
yum remove mari* -y
pxc依赖的端口：
pxc集群要使用四个端口，所以防火墙要放行这些端口
下载pxc的地址：https://www.percona.com/downloads/Percona-XtraDB-Cluster-LATEST/
下载安装依赖yum localinstall –y percona-xtrabackup-24-2.4.11-1.el7.x86_64.rpm
下载安装qpress
ftp://ftp.pbone.net/mirror/ftp5.gwdg.de/pub/opensuse/repositories/home:/AndreasStieger:/branches:/Archiving/CentOS_CentOS-7/x86_64/qpress-1.1-8.1.x86_64.rpm
yum localinstall –y qpress-1.1-8.1.x86_64.rpm
gzip Percona-XtraDB-Cluster-5.7.21-29.26-r390-el7-x86_64-bundle.tar
tar –zxf Percona-XtraDB-Cluster-5.7.21-29.26-r390-el7-x86_64-bundle.tar.gz
保留下面的安装包：
Percona-XtraDB-Cluster-57-5.7.21-29.26.1.el7.x86_64.rpm
Percona-XtraDB-Cluster-client-57-5.7.21-29.26.1.el7.x86_64.rpm
Percona-XtraDB-Cluster-server-57-5.7.21-29.26.1.el7.x86_64.rpm
Percona-XtraDB-Cluster-shared-57-5.7.21-29.26.1.el7.x86_64.rpm
Percona-XtraDB-Cluster-shared-compat-57-5.7.21-29.26.1.el7.x86_64.rpm
# 安装集群
yum localinstall –y Percona-XtraDB-Cluster-*.rpm
# 添加配置，原本的配置分散集中到/etc/my.cnf中
# 配置文件
[root@node1 ~]# cat /etc/my.cnf
[client]
socket=/var/lib/mysql/mysql.sock
[mysqld]
# 每个节点要不同
server-id=1
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
log-bin
log_slave_updates
expire_logs_days=7
# 数据库字符集
character_set_server = utf8
bind-address = 0.0.0.0
#跳过DNS解析
skip-name-resolve
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
wsrep_provider=/usr/lib64/galera3/libgalera_smm.so
wsrep_cluster_name=pxc-cluster
# 集群的IP地址
wsrep_cluster_address=gcomm://10.11.0.210,10.11.0.212,10.11.0.215
wsrep_node_name=pxc1
# 本机IP地址
wsrep_node_address=10.11.0.210
wsrep_sst_method=xtrabackup-v2
wsrep_sst_auth= admin:Abc_123456
pxc_strict_mode=ENFORCING
binlog_format=ROW
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
# 启动主节点10.11.0.210
systemctl start mysql@bootstrap.service
# 找到mysql的root密码
[root@node1 ~]# cat /var/log/mysqld.log |grep pass
2018-11-27T09:48:59.769033Z 1 [Note] A temporary password is generated for root@localhost: =K%uzAZda55f
# 登录mysql重置root密码
alter user 'root'@'localhost' identified by 'root';
# 添加同步用户，启动从节点root密码和admin的账号信息就同步到了从节点
create user 'admin'@'localhost' identified by 'Abc_123456';
grant reload,lock tables,replication client,process on *.* to 'admin'@'localhost';
flush privileges;
# 启动从节点
systemctl start mysql
查询集群状态show status like 'wsrep_cluster%';
数据库复制的相关信息
在pxc01上创建库，表并且插入数据，可以看到能够正常同步
create database chinasoft charset='utf8mb4';
use chinasoft;
create table students(id int primary key, name varchar(200));
insert into students(id,name) values(1,'jack');
同理在pxc02和pxc03上插入数据，也可以同步到其他节点