Mysql MGR + Consul + Consul-template + Haproxy 搭建mysql 高可用集群 （二）

Mysql MGR 的搭建：

下载新版的mysql 8.0.13

wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.13-el7-x86_64.tar

　　

使用uuidgen命令生成个uuid：

uuidgen
cc5e2627-2285-451f-86e6-0be21581539f

　　

三台物理机部署：

修改hosts文件：

vi /etc/hosts
172.16.0.90 swarm1
172.16.0.76 swarm2
172.16.0.175 swarm3

　　

创建工作目录：

mkdir /data/mysql_root/base_phony/40010
mkdir /data/mysql_root/data/40010

#将解压后的mysql软体放到/data/mysql_root/base_phony/40010下
chown -R mysql:mysql  /data/mysql_root/base_phony/40010
chown -R mysql:mysql /data/mysql_root/data/40010

　　

创建my.cnf文件：已swarm1的为例

（swarm1的server-id为1，swarm1的server-id为2，swarm1的server-id为3；group_replication_local_address修改为本机hostname或ip）

cd /data/mysql_root/data/40010
vi my.cnf
[client]
port = 40010
socket = /tmp/mysql_40010.sock
[mysqld]
port = 40010
socket = /tmp/mysql_40010.sock
datadir = /data/mysql_root/data/40010
slow_query_log_file = /data1/mysql_root/data/40010/slow_query.log
log-error = /data/mysql_root/data/40010/error.log 
server-id = 1
#for MGR
gtid_mode=on
enforce-gtid-consistency=on
binlog_checksum=NONE
loose-group_replication_ip_whitelist="swarm1,swarm2,swarm3"
loose-group_replication_group_name="cc5e2627-2285-451f-86e6-0be21581539f"
loose-group_replication_local_address="swarm1:2525"
loose-group_replication_group_seeds="swarm1:2525,swarm22525,swarm3:2525"

参照官方文档，mysql8中一些默认参数不用为MGR修改。

初始化mysql：

cd  /data/mysql_root/base_phony/40010/bin/
./mysqld --defaults-file=/data/mysql_root/data/40010/my.cnf --basedir=/data/mysql_root/base_phony/40010 --initialize-insecure --user=mysql

启动mysql：

nohup /data/mysql_root/base_phony/40010/bin/mysqld --defaults-file=/data/mysql_root/data/40010/my.cnf --basedir=/data/mysql_root/base_phony/40010 --user=mysql &

安装MGR插件：

mysql -uroot -S /home/mysql/mysql40010/mysql40010.sock
mysql> install plugin group_replication soname 'group_replication.so';

　　

至此，三台MGR实例初始化完毕，接下来配置启动MGR

登录swarm1的mysql：

set sql_log_bin=0;
CREATE USER repl@'%' IDENTIFIED WITH 'mysql_native_password' BY 'repl';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';
FLUSH PRIVILEGES;
set sql_log_bin=1;
CHANGE MASTER TO MASTER_USER='repl',MASTER_PASSWORD='repl'  FOR CHANNEL 'group_replication_recovery';

#  group_replication_bootstrap_group参数仅在第一台启动的MGR实例上开启，其他实例不要操作
set global group_replication_bootstrap_group=ON;
START GROUP_REPLICATION; 
set global group_replication_bootstrap_group=OFF;

SELECT * FROM performance_schema.replication_group_members;

登录swarm2、swarm3的mysql：

set sql_log_bin=0;
CREATE USER repl@'%' IDENTIFIED WITH 'mysql_native_password' BY 'repl';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';
FLUSH PRIVILEGES;
set sql_log_bin=1;
CHANGE MASTER TO MASTER_USER='repl',MASTER_PASSWORD='repl'  FOR CHANNEL 'group_replication_recovery';

START GROUP_REPLICATION; 
SELECT * FROM performance_schema.replication_group_members;

 至此，一个三节点的MGR集群搭建完毕，可以实现MGR的特性了。

+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| group_replication_applier | bbdb8668-1866-11e9-89a5-525400447342 | swarm1 | 40010 | ONLINE | PRIMARY | 8.0.13 |
| group_replication_applier | c433a5af-1866-11e9-96b6-525400cd1c31 | swarm2 | 40010 | ONLINE | SECONDARY | 8.0.13 |
| group_replication_applier | eabb341d-1895-11e9-90dd-525400dd19e5 | swarm3 | 40010 | ONLINE | SECONDARY | 8.0.13 |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+

遇到的问题：

发现节点重启后经常性的无法加入集群，检查报错日志如下：

2019-01-16T15:38:02.952875Z 651 [ERROR] [MY-010584] [Repl] Slave I/O for channel 'group_replication_recovery': error connecting to master 'repl@swarm3:40010' - retry-time: 60  retries: 1, Error_code: MY-002061

反复检查复制用户的账号密码，未发现错误，开始使用的创建语句是：

CREATE USER repl@'%' IDENTIFIED BY 'repl';

修改为：

CREATE USER repl@'%' IDENTIFIED WITH 'mysql_native_password' BY 'repl';

此后节点间间接未发生问题，应该是和mysql8修改了默认加密方式有关。