【mysql集群】三、MaxScale实现读写分离与负载均衡

MaxScale：实现MySQL读写分离与负载均衡的中间件利器

http://ju.outofmemory.cn/entry/276547
https://www.cnblogs.com/darren-lee/p/7591416.html

测试读写分离：
https://blog.csdn.net/wjf870128/article/details/51218697/

• maxscale 可以安装在任意一台服务器上

• 在开始配置之前，需要在 master 中为 MaxScale 创建两个用户，用于监控模块和路由模块。

创建监控用户

mysql> create user scalemon@’%’ identified by “111111”;mysql> grant replication slave, replication client on . to scalemon@’%’;
创建路由用户

mysql> create user route@’%’ identified by “111111”;
mysql> grant select on mysql.* to route@’%’;

maxscale 中间件配置

参考博客： https://blog.csdn.net/LYK_for_dba/article/details/78351124

maxscale 实现读写分离
https://blog.csdn.net/wjf870128/article/details/51218697/

maxscale.cnf 配置文件

# MaxScale documentation on GitHub:
# https://github.com/mariadb-corporation/MaxScale/blob/2.1/Documentation/Documentation-Contents.md

# Global parameters
#
# Complete list of configuration options:
# https://github.com/mariadb-corporation/MaxScale/blob/2.1/Documentation/Getting-Started/Configuration-Guide.md

[maxscale]
threads=1 #线程开启数，设置auto同cpu核数一致
ms_timestamp=1 #timesstamp精确度 ts=秒
syslog=1 #将日志写到syslog
maxlog=1 #将日志写到maxscale的日志文件中
log_to_shm=0 #日志不写入共享缓存
log_warning=1 #记录警告信息
log_notice=0 #不记录notice
log_info=0 #不记录info
log_debug=0 #不打开debug模式
log_augmentation=1 #日志递增
use_sql_variables_in=MASTER #带参数查询route 到master


# 相关目录配置
# #路径如果没有在外面手动创建好
logdir=/data/maxscale/log/
datadir=/data/maxscale/data/
libdir=/usr/lib64/maxscale/
cachedir=/data/maxscale/cache/
piddir=/data/maxsc

# Server definitions
#
# Set the address of the server to the network
# address of a MySQL server.
#

[server1]
type=server
address=192.168.9.38
port=3306
protocol=MySQLBackend

[server2]
type=server
address=192.168.9.81
port=3306
protocol=MySQLBackend

[server3]
type=server
address=192.168.9.98
port=3306
protocol=MySQLBackend
# Monitor for the servers
#
# This will keep MaxScale aware of the state of the servers.
# MySQL Monitor documentation:
# https://github.com/mariadb-corporation/MaxScale/blob/2.1/Documentation/Monitors/MySQL-Monitor.md

[MySQL Monitor]
type=monitor
module=mysqlmon
servers=server1,server2,server3
user=maxscale
passwd=123456
monitor_interval=10000  # 监控mysql 的用户名和密码

#detect_replication_lag=true #监控主从同步状态和信息
#detect_stale_master=true #监控主从复制 slave全部挂掉时，所有访问全部指向master

# Service definitions
#
# Service Definition for a read-only service and
# a read/write splitting service.
#

# ReadConnRoute documentation:
# https://github.com/mariadb-corporation/MaxScale/blob/2.1/Documentation/Routers/ReadConnRoute.md

#读写服务器监听
[Read-Write Listener]
type=listener
service=Read-Write Service
protocol=MySQLClient
port=4006

[Read-Only Service]
type=service
router=readconnroute
servers=server1,server2,server3
user=maxscale
passwd=123456
router_options=slave
#
## ReadWriteSplit documentation:
## https://github.com/mariadb-corporation/MaxScale/blob/2.1/Documentation/Routers/ReadWriteSplit.md
#
[Read-Write Service]
type=service
router=readwritesplit
servers=server1,server2,server3
user=maxscale
passwd=123456
max_slave_connections=100%


# This service enables the use of the MaxAdmin interface
# MaxScale administration guide:
# https://github.com/mariadb-corporation/MaxScale/blob/2.1/Documentation/Reference/MaxAdmin.md

[MaxAdmin Service]
type=service
router=cli

# Listener definitions for the services
#
# These listeners represent the ports the
# services will listen on.
#

[Read-Only Listener]
type=listener
service=Read-Only Service
protocol=MySQLClient
port=4008



[MaxAdmin Listener]
type=listener
service=MaxAdmin Service
protocol=maxscaled
socket=default

• maxpasswd 生成加密密码失效， 直接输入原始密码
• 启动maxscale:

maxscale -f /etc/maxscale.cnf

(如果启动有报错，看下报错日志信息):
netstat -naplt|grep maxscale 查看是否启动
* 使用maxadmin 查看服务

maxadmin -S /tmp/maxadmin.sock

list server
list services

maxscale 启动成功

[root@iZwz9hl75gse44a4mjqc05Z ~]# maxadmin -S /tmp/maxadmin.sock
MaxScale> list servers
Servers.
-------------------+-----------------+-------+-------------+--------------------
Server             | Address         | Port  | Connections | Status              
-------------------+-----------------+-------+-------------+--------------------
server1            | **************  |  3306 |           0 | Master, Running
server2            | **************    |  3306 |           0 | Slave, Running
server3            | **************    |  3306 |           0 | Slave, Running
-------------------+-----------------+-------+-------------+--------------------

==注意事项：==

这个错误是由于 阿里云服务器 开启安全组规则 没有开启3306 端口：
[root@iZwz9hl75gse44a4mjqc05Z ~]# maxadmin -S /tmp/maxadmin.sock
MaxScale> list servers
Servers.
-------------------+-----------------+-------+-------------+--------------------
Server             | Address         | Port  | Connections | Status              
-------------------+-----------------+-------+-------------+--------------------
server1            | **************  |  3306 |           0 | Running
server2            |**************   |  3306 |           0 | down
server3            | *************   |  3306 |           0 | down 
-------------------+-----------------+-------+-------------+--------------------

• 阿里云服务器 开启安全组规则：3306、4006、4008 端口开放
• iptables 防火墙 3306、4006/4008 端口开放