Mysql MGR + Consul + Consul-template + Haproxy 搭建mysql 高可用集群 （四）

Haproxy + Consul-template 对外提供服务：

安装haproxy：

yum install haproxy

按照consul-template要求修改frontend和backend，制作配置文件模板：

cd /etc/haproxy/
mv haproxy.cfg haproxy.cfg.tpl
vi haproxy.cfg.tpl
frontend proxy_rw
    mode tcp
    bind *:22014
    maxconn 66666
    option clitcpka
    default_backend mysql_servers_rw

backend mysql_servers_rw
    mode tcp
    option tcp-check
{{range service "mysql_rw"}}    
    server {{.Address}} {{.Address}}:{{.Port}} check inter 10s maxconn 66666   
{{end}}

frontend proxy_ro
    mode tcp
    bind *:22015
    maxconn 66666
    option clitcpka
    default_backend mysql_servers_ro

backend mysql_servers_ro
    mode tcp
    option tcp-check
{{range service "mysql_ro"}}
    server {{.Address}} {{.Address}}:{{.Port}} check inter 10s maxconn 66666
{{end}}

启动consul-template：

cd /root/consul
#swarm1:
nohup consul-template  -consul-addr 172.16.0.90:8500 -template /etc/haproxy/haproxy.cfg.tpl:/etc/haproxy/haproxy.cfg:"systemctl restart haproxy.service" >> consul-template.log &
#swarm2:
nohup consul-template  -consul-addr 172.16.0.76:8500 -template /etc/haproxy/haproxy.cfg.tpl:/etc/haproxy/haproxy.cfg:"systemctl restart haproxy.service" >> consul-template.log &
#swarm3:
nohup consul-template  -consul-addr 172.16.0.175:8500 -template /etc/haproxy/haproxy.cfg.tpl:/etc/haproxy/haproxy.cfg:"systemctl restart haproxy.service" >> consul-template.log &

检查haproxy配置文件及启动情况：

systemctl status haproxy.service
cat /etc/haproxy/haproxy.cfg
frontend proxy_rw
    mode tcp
    bind *:22014
    maxconn 66666
    option clitcpka
    default_backend mysql_servers_rw

backend mysql_servers_rw
    mode tcp
    option tcp-check
    
    server 172.16.0.90 172.16.0.90:40010 check inter 10s maxconn 66666   


frontend proxy_ro
    mode tcp
    bind *:22015
    maxconn 66666
    option clitcpka
    default_backend mysql_servers_ro

backend mysql_servers_ro
    mode tcp
    option tcp-check

    server 172.16.0.76 172.16.0.76:40010 check inter 10s maxconn 66666

    server 172.16.0.175 172.16.0.175:40010 check inter 10s maxconn 66666

验证连接情况，使用haproxy配置的新端口：

[root@swarm1 ~]# mysql -uqxy -pqxy -hswarm1 -P22014 -e "show variables like '%hostname%';"
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------+--------+
| Variable_name | Value  |
+---------------+--------+
| hostname      | swarm1 |
+---------------+--------+
[root@swarm1 ~]# mysql -uqxy -pqxy -hswarm1 -P22015 -e "show variables like '%hostname%';"
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------+--------+
| Variable_name | Value  |
+---------------+--------+
| hostname      | swarm2 |
+---------------+--------+
[root@swarm1 ~]# mysql -uqxy -pqxy -hswarm1 -P22015 -e "show variables like '%hostname%';"
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------+--------+
| Variable_name | Value  |
+---------------+--------+
| hostname      | swarm3 |
+---------------+--------+

至此一个3节点MGR集群部署完毕，三个集群模式haproxy对外提供服务，前面加一层网络负载均衡就彻底OK了。。。

备注：

这种部署模式中，consul成为了高可用关键点，如果同一主机上，consul 客户端发生异常，而mysql工作正常，则会出现问题，需要思考解决。。