Ansible 自动化运维工具部署主从数据库+读写分离

Ansible 自动化运维工具部署主从数据库+读写分离

一、主从复制和读写分离介绍

数据库主从复制是一种常见的数据库架构，用于提高数据库的可用性、可扩展性和性能。它通过将写操作（主节点）复制到一个或多个从节点来实现数据的同步。

主从复制的工作原理如下：

1. 首先，将一个数据库节点指定为主节点，所有的写操作都在主节点上执行。
2. 主节点将写操作记录到二进制日志（binary log）中，并将这些日志发送到从节点。
3. 从节点接收到二进制日志后，将其应用到自己的数据库上，实现数据的同步。

读写分离是基于主从复制的，核心思想是将读操作分发到多个从节点上，而将写操作集中在主节点上。Mycat是一个开源的数据库中间件，支持读写分离，将读操作和写操作分别分发到不同的数据库节点上

二、准备工作

（1）节点规划

准备三台服务器，centos7.9.2009

IP	节点
192.168.100.10	ansible
192.168.100.20	master
192.168.100.30	slave
192.168.100.40	mycat

（2）修改主机名

1. 修改主机名
# ansible节点
[root@localhost ~]# hostnamectl set-hostname ansible
[root@localhost ~]# bash
[root@ansible ~]#
# master节点
[root@localhost ~]# hostnamectl set-hostname master
[root@localhost ~]# bash
[root@master ~]#
# slave节点
[root@localhost ~]# hostnamectl set-hostname slave
[root@localhost ~]# bash
[root@slave ~]#
# mycat节点
[root@localhost ~]# hostnamectl set-hostname mycat
[root@localhost ~]# bash
[root@mycat ~]# 

（3）免密

[root@ansible ~]# ssh-keygen
[root@master ~]# ssh-keygen
[root@slave ~]# ssh-keygen
[root@mycat ~]# ssh-keygen[root@ansible ~]# ssh-copy-id 192.168.100.20
[root@ansible ~]# ssh-copy-id 192.168.100.30
[root@ansible ~]# ssh-copy-id 192.168.100.40

（4）配置IP映射

[root@ansible ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.100.10 ansible
192.168.100.20 master
192.168.100.30 slave
192.168.100.40 mycat

（5）安装ansible

[root@ansible ~]# yum install -y epel-release vim tree
[root@ansible ~]# yum install -y ansible 
[root@ansible ~]# ansible --version
ansible 2.9.27config file = /etc/ansible/ansible.cfgconfigured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']ansible python module location = /usr/lib/python2.7/site-packages/ansibleexecutable location = /usr/bin/ansiblepython version = 2.7.5 (default, Oct 14 2020, 14:45:30) [GCC 4.8.5 20150623 (Red Hat 4.8.5-44)]

（6）配置主机清单文件

[root@ansible ~]# vim /etc/ansible/hosts 
[master]
192.168.100.20
[slave]
192.168.100.30
[mycat]
192.168.100.40[root@ansible ~]# ansible all -m ping
192.168.100.30 | SUCCESS => {"ansible_facts": {"discovered_interpreter_python": "/usr/bin/python"}, "changed": false, "ping": "pong"
}
192.168.100.20 | SUCCESS => {"ansible_facts": {"discovered_interpreter_python": "/usr/bin/python"}, "changed": false, "ping": "pong"

三、目录结构

（1）创建项目目录

[root@ansible ~]# mkdir mycat_mariadb
[root@ansible ~]# cd mycat_mariadb/

（2）创建角色目录

在创建roles之前，我们将数据库读写分离部署的步骤分为 3个role执行，这样更加易懂

init（初始化）

mysql（主从复制）

mycat（读写分离）

[root@ansible mycat_mariadb]# mkdir -p  roles/{mysql-master,mysql-slave,init,mycat,mysql-create-testdb}/{templates,tasks,files} 

这次项目中会用到template、tasks、files目录，可以选择性创建，自己用到哪个创建哪个

（3）创建变量目录

创建该目录用来存放变量

[root@ansible mycat_mariadb]# mkdir group_vars
[root@ansible mycat_mariadb]# vim group_vars/all
PASSWD: '000000'
master_host: 192.168.100.20
slave_host: 192.168.100.30
mycat_host: 192.168.100.40
shujuku: testdb

（4）init角色

这一步操作是用来创建数据库主从复制，以及读写分离的配置文件

master-my.cnf.j2文件内容

[root@ansible mycat_mariadb]# vim roles/mysql-master/files/master-my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
server-id=20
log_bin = mysql-bin
binlog-ignore-db=mysql
binlog-do-db=testdb
binlog_format=STATEMENT
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

slave-my.cnf.j2 文件内容

[root@ansible mycat_mariadb]# vim roles/mysql-slave/files/slave-my.cnf[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemdserver_id=30
relay-log=mysql-relay
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

server.xml.j2 文件内容

[root@ansible mycat_mariadb]# vim roles/mycat/templates/server.xml.j2 
<?xml version="1.0" encoding="UTF-8"?>
<!-- - - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -->
<!DOCTYPE mycat:server SYSTEM "server.dtd">
<mycat:server xmlns:mycat="http://io.mycat/"><system><property name="useSqlStat">0</property>  <!-- 1为开启实时统计、0为关闭 --><property name="useGlobleTableCheck">0</property>  <!-- 1为开启全加班一致性检测、0为关闭 --><property name="sequnceHandlerType">2</property><!--  <property name="useCompression">1</property>--> <!--1为开启mysql压缩协议--><!--  <property name="fakeMySQLVersion">5.6.20</property>--> <!--设置模拟的MySQL版本号--><!-- <property name="processorBufferChunk">40960</property> --><!-- <property name="processors">1</property> <property name="processorExecutor">32</property> --><!--默认为type 0: DirectByteBufferPool | type 1 ByteBufferArena--><property name="processorBufferPoolType">0</property><!--默认是65535 64K 用于sql解析时最大文本长度 --><!--<property name="maxStringLiteralLength">65535</property>--><!--<property name="sequnceHandlerType">0</property>--><!--<property name="backSocketNoDelay">1</property>--><!--<property name="frontSocketNoDelay">1</property>--><!--<property name="processorExecutor">16</property>--><!--<property name="serverPort">8066</property> <property name="managerPort">9066</property> <property name="idleTimeout">300000</property> <property name="bindIp">0.0.0.0</property> <property name="frontWriteQueueSize">4096</property> <property name="processors">32</property> --><!--分布式事务开关，0为不过滤分布式事务，1为过滤分布式事务（如果分布式事务内只涉及全局表，则不过滤），2为不过滤分布式事务,但是记录分布式事务日志--><property name="handleDistributedTransactions">0</property><!--off heap for merge/order/group/limit      1开启   0关闭--><property name="useOffHeapForMerge">1</property><!--单位为m--><property name="memoryPageSize">1m</property><!--单位为k--><property name="spillsFileBufferSize">1k</property><property name="useStreamOutput">0</property><!--单位为m--><property name="systemReserveMemorySize">384m</property><!--是否采用zookeeper协调切换  --><property name="useZKSwitch">true</property></system><!-- 全局SQL防火墙设置 --><!-- <firewall> <whitehost><host host="127.0.0.1" user="mycat"/><host host="127.0.0.2" user="mycat"/></whitehost><blacklist check="false"></blacklist></firewall>--><user name="root"><property name="password">{{PASSWD}}</property><property name="schemas">TESTDB</property><!-- 表级 DML 权限设置 --><!-- <privileges check="false"><schema name="TESTDB" dml="0110" ><table name="tb01" dml="0000"></table><table name="tb02" dml="1111"></table></schema></privileges>--></user><user name="user"><property name="password">{{PASSWD}}</property><property name="schemas">TESTDB</property><property name="readOnly">true</property></user></mycat:server>

schema.xml.j2 文件内容

[root@ansible mycat_mariadb]# vim roles/mycat/templates/schema.xml.j2 <?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/"><schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1"></schema><dataNode name="dn1" dataHost="host1" database="{{shujuku}}" /><dataHost name="host1" maxCon="1000" minCon="10" balance="3"writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100"><heartbeat>select user()</heartbeat><writeHost host="hostM1" url="{{master_host}}:3306" user="root"password="{{PASSWD}}"><readHost host="hostS1" url="{{slave_host}}:3306" user="root" password="{{PASSWD}}" /></writeHost></dataHost>
</mycat:schema>

mycat.sh

[root@ansible mycat_mariadb]# vim roles/mycat/files/mycat.sh
#!/bin/bash
cd /usr/local/mycat/bin/ && ./mycat start

（5）编写剧本入口文件

将调用roles的顺序及哪些主机调用哪些roles在这个文件夹中体现出来

[root@ansible mycat_mariadb]# vim mycat_mariadb.yaml 
- hosts: allremote_user: rootroles:- init- hosts: masterremote_user: rootroles:- mysql-master- hosts: slaveremote_user: rootroles:- mysql-slave- hosts: mycatremote_user: rootroles:- mycat

四、编写角色任务文件

（1）init初始化任务文件

[root@ansible tasks]# vim /root/mycat_mariadb/roles/init/tasks/main.yaml - name: 配置所有主机的host映射copy: src=/etc/hosts dest=/etc/hosts- name: 关闭防火墙shell: systemctl stop firewalld && systemctl disable firewalld && setenforce 0- name: 安装mariadb expectshell: yum install -y mariadb-server expect- name: 设置开机自启并开启mariadbshell: systemctl enable mariadb --now- name: 设置密码shell: mysqladmin -uroot password '{{PASSWD}}'- name: 安装MySQL-pythonshell: yum install -y MySQL-python

（2）mysql-master任务文件

[root@ansible tasks]# vim /root/mycat_mariadb/roles/mysql-master/tasks/main.yaml - name: 移动文件copy: src=master-my.cnf dest=/etc/my.cnf- name: 重新启动mariadbshell: systemctl restart mariadb- name: 设置root用户访问权限shell: mysql -uroot -p{{PASSWD}} -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '{{PASSWD}}';flush privileges;"- name: 创建数据库用户用于复制shell: mysql -uroot -p{{PASSWD}} -e "grant replication slave on *.* to 'csq'@'192.168.100.%' identified by '{{PASSWD}}';"- name: 存放变量Log_nameshell: mysql -uroot -p{{PASSWD}} -e "show master status;"|awk 'NR==2{print $1}'register: file
- name: 存放变量File_sizeshell: mysql -uroot -p{{PASSWD}} -e "show master status;"|awk 'NR==2{print $2}'register: pot- name: 设置全局变量set_fact: masterbin={{ file.stdout_lines[0] }}   
- name: 设置全局变量set_fact: position={{ pot.stdout_lines[0] }}  

（3）mysql-slave任务文件

[root@ansible mycat_mariadb]# vim roles/mysql-slave/tasks/main.yaml- name: 移动文件copy: src=slave-my.cnf  dest=/etc/my.cnf
- name: 重启mariadbshell: systemctl restart mariadb- name: 设置root用户访问权限shell: mysql -uroot -p{{PASSWD}} -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '{{PASSWD}}';flush privileges;"- name: 设置主数据信息mysql_replication:login_user: rootlogin_password: '000000'mode: changemastermaster_user: csqmaster_password: '000000'master_host: 192.168.100.20master_log_file: "{{ hostvars['192.168.100.20']['masterbin'] }}"master_log_pos: "{{ hostvars['192.168.100.20']['position'] }}"- name: 开启slaveshell: mysql -uroot -p{{PASSWD}} -e "start slave;"  - name: 定义输出的信息shell: mysql -uroot -p{{PASSWD}} -e "show slave status\G;" | grep -E "Slave_IO_Running|Slave_SQL_Running"register: slave_status_output
- name: 打印输出的信息debug:var: slave_status_output.stdout

（4）mysql-create-testdb任务文件

[root@ansible mycat_mariadb]# vim roles/mysql-create-testdb/tasks/main.yaml
- name: 创建用于复制的testdb库shell: mysql -uroot -p000000 -e "create database testdb;"
- name: 创建表插入数据shell: mysql -uroot -p000000 -e "use testdb; create table mytbl(id int,name varchar(20));insert into mytbl values(1,'csq');"

（5）mycat任务文件

[root@ansible mycat_mariadb]# vim roles/mycat/tasks/main.yaml- name: 设置root用户访问权限shell: mysql -uroot -p{{PASSWD}} -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '{{PASSWD}}';flush privileges;"- name: 安装openjdkshell: yum install -y java-1.8.0-openjdk  java-1.8.0-openjdk-devel wget net-tools- name: 下载Mycat软件包shell: wget http://dl.mycat.org.cn/1.6-RELEASE/Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz- name: 解压Mycat软件包到/usr/localshell:  tar -zxvf /root/Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz -C /usr/local/- name: 复制模板文件template: src=schema.xml.j2 dest=/usr/local/mycat/conf/schema.xml- name: 复制模板文件template: src=server.xml.j2 dest=/usr/local/mycat/conf/server.xml- name: 开启mycatshell: /bin/bash /usr/local/mycat/bin/mycat start

五、执行playbook

[root@ansible mycat_mariadb]# ansible-playbook mycat_mariadb.yaml     PLAY [all] ************************************************************************************************************************************************************TASK [Gathering Facts] ************************************************************************************************************************************************
ok: [192.168.100.40]
ok: [192.168.100.30]
ok: [192.168.100.20]TASK [init : 配置所有主机的host映射] *******************************************************************************************************************************************
changed: [192.168.100.40]
changed: [192.168.100.20]
changed: [192.168.100.30]TASK [init : 关闭防火墙] ***************************************************************************************************************************************************
changed: [192.168.100.40]
changed: [192.168.100.30]
changed: [192.168.100.20]TASK [init : 安装mariadb expect] ****************************************************************************************************************************************
[WARNING]: Consider using the yum module rather than running 'yum'.  If you need to use command because yum is insufficient you can add 'warn: false' to this command
task or set 'command_warnings=False' in ansible.cfg to get rid of this message.
changed: [192.168.100.40]
changed: [192.168.100.30]
changed: [192.168.100.20]TASK [init : 设置开机自启并开启mariadb] ****************************************************************************************************************************************
changed: [192.168.100.30]
changed: [192.168.100.40]
changed: [192.168.100.20]TASK [init : 设置密码] ****************************************************************************************************************************************************
changed: [192.168.100.30]
changed: [192.168.100.20]
changed: [192.168.100.40]TASK [init : 安装MySQL-python] ******************************************************************************************************************************************
changed: [192.168.100.40]
changed: [192.168.100.30]
changed: [192.168.100.20]PLAY [master] *********************************************************************************************************************************************************TASK [Gathering Facts] ************************************************************************************************************************************************
ok: [192.168.100.20]TASK [mysql-master : 移动文件] ********************************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-master : 重新启动mariadb] *************************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-master : 设置root用户访问权限] ************************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-master : 创建数据库用户用于复制] *************************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-master : 存放变量Log_name] ************************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-master : 存放变量File_size] ***********************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-master : 设置全局变量] ******************************************************************************************************************************************
ok: [192.168.100.20]TASK [mysql-master : 设置全局变量] ******************************************************************************************************************************************
ok: [192.168.100.20]PLAY [slave] **********************************************************************************************************************************************************TASK [Gathering Facts] ************************************************************************************************************************************************
ok: [192.168.100.30]TASK [mysql-slave : 移动文件] *********************************************************************************************************************************************
changed: [192.168.100.30]TASK [mysql-slave : 重启mariadb] ****************************************************************************************************************************************
changed: [192.168.100.30]TASK [mysql-slave : 设置root用户访问权限] *************************************************************************************************************************************
changed: [192.168.100.30]TASK [mysql-slave : 设置主数据信息] ******************************************************************************************************************************************
changed: [192.168.100.30]TASK [mysql-slave : 开启slave] ******************************************************************************************************************************************
changed: [192.168.100.30]TASK [mysql-slave : 定义输出的信息] ******************************************************************************************************************************************
changed: [192.168.100.30]TASK [mysql-slave : 打印输出的信息] ******************************************************************************************************************************************
ok: [192.168.100.30] => {"slave_status_output.stdout": "             Slave_IO_Running: Yes\n            Slave_SQL_Running: Yes"
}PLAY [master] *********************************************************************************************************************************************************TASK [Gathering Facts] ************************************************************************************************************************************************
ok: [192.168.100.20]TASK [mysql-create-testdb : 创建用于复制的testdb库] ***************************************************************************************************************************
changed: [192.168.100.20]TASK [mysql-create-testdb : 创建表插入数据] **********************************************************************************************************************************
changed: [192.168.100.20]PLAY [mycat] **********************************************************************************************************************************************************TASK [Gathering Facts] ************************************************************************************************************************************************
ok: [192.168.100.40]TASK [mycat : 设置root用户访问权限] *******************************************************************************************************************************************
changed: [192.168.100.40]TASK [mycat : 安装openjdk] **********************************************************************************************************************************************
changed: [192.168.100.40]TASK [mycat : 下载Mycat软件包] *********************************************************************************************************************************************
[WARNING]: Consider using the get_url or uri module rather than running 'wget'.  If you need to use command because get_url or uri is insufficient you can add 'warn:
false' to this command task or set 'command_warnings=False' in ansible.cfg to get rid of this message.
changed: [192.168.100.40]TASK [mycat : 解压Mycat软件包到/usr/local] **********************************************************************************************************************************
[WARNING]: Consider using the unarchive module rather than running 'tar'.  If you need to use command because unarchive is insufficient you can add 'warn: false' to
this command task or set 'command_warnings=False' in ansible.cfg to get rid of this message.
changed: [192.168.100.40]TASK [mycat : 复制模板文件] *************************************************************************************************************************************************
changed: [192.168.100.40]TASK [mycat : 复制模板文件] *************************************************************************************************************************************************
changed: [192.168.100.40]TASK [开启mycat] ********************************************************************************************************************************************************
changed: [192.168.100.40]PLAY RECAP ************************************************************************************************************************************************************
192.168.100.20             : ok=19   changed=14   unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   
192.168.100.30             : ok=15   changed=12   unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   
192.168.100.40             : ok=15   changed=13   unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   

在执行过程中会打印出这两条信息，如果都是YES 说明你主从配置成功了

六、验证主从复制读写分离

（1）登录mycat管理窗口

[root@mycat ~]# mysql -uroot -p000000 -h127.0.0.1 -P 9066

查看读写配置情况

MySQL [(none)]> show @@datasource;
+----------+--------+-------+----------------+------+------+--------+------+------+---------+-----------+------------+
| DATANODE | NAME   | TYPE  | HOST           | PORT | W/R  | ACTIVE | IDLE | SIZE | EXECUTE | READ_LOAD | WRITE_LOAD |
+----------+--------+-------+----------------+------+------+--------+------+------+---------+-----------+------------+
| dn1      | hostM1 | mysql | 192.168.100.20 | 3306 | W    |      0 |   10 | 1000 |      57 |         0 |          1 |
| dn1      | hostS1 | mysql | 192.168.100.30 | 3306 | R    |      0 |    5 | 1000 |      53 |         2 |          0 |
+----------+--------+-------+----------------+------+------+--------+------+------+---------+-----------+------------+
参数详解：
DATANODE：数据节点的名称
NAME：数据节点的标识名称
TYPE：数据节点的类型，这里是mysql
HOST：数据节点的主机地址
PORT：数据节点的端口号
W/R：数据节点的读写类型，W表示写入，R表示读取
ACTIVE：当前活跃连接数
IDLE：当前空闲连接数
ZE：连接池大小，即连接池中的最大连接数
EXECUTE：执行次数，表示该数据节点的执行操作次数
READ_LOAD：读取负载，表示该数据节点的读取负载情况

查看心跳信息

MySQL [(none)]> show @@heartbeat;
+--------+-------+----------------+------+---------+-------+--------+---------+--------------+---------------------+-------+
| NAME   | TYPE  | HOST           | PORT | RS_CODE | RETRY | STATUS | TIMEOUT | EXECUTE_TIME | LAST_ACTIVE_TIME    | STOP  |
+--------+-------+----------------+------+---------+-------+--------+---------+--------------+---------------------+-------+
| hostM1 | mysql | 192.168.100.20 | 3306 |       1 |     0 | idle   |       0 | 1,1,1        | 2023-09-13 15:27:30 | false |
| hostS1 | mysql | 192.168.100.30 | 3306 |       1 |     0 | idle   |       0 | 1,0,1        | 2023-09-13 15:27:30 | false |
+--------+-------+----------------+------+---------+-------+--------+---------+--------------+---------------------+-------+
参数详解：
NAME：心跳节点的名称
TYPE：心跳节点的类型，这里是mysql
HOST：心跳节点的主机地址
PORT：心跳节点的端口号
RS_CODE：复制状态码，用于判断复制是否正常进行 (1表示主从复制正常进行)
RETRY：重试次数，表示心跳节点尝试重连的次数
STATUS：心跳节点的状态，包括idle（空闲）和active（活跃）
TIMEOUT：超时时间，表示心跳节点的超时时间
EXECUTE_TIME：执行时间，表示心跳节点的执行时间
LAST_ACTIVE_TIME：最后活跃时间，表示心跳节点最后一次发送心跳的时间

（2）读写分离验证

[root@mycat ~]# mysql -uroot -p000000 -h127.0.0.1 -P 8066
MySQL [(none)]> use TESTDB;
MySQL [TESTDB]> insert into mytbl values(1,@@hostname); # 插入数据
MySQL [TESTDB]> select * from mytbl; # 查询数据，自动跳转从主机进行查询
+------+-------+
| id   | name  |
+------+-------+
|    1 | csq   |
|    1 | slave |
+------+-------+
# @@hostname是MySQL系统变量，表示当前数据库服务器的主机名。
# 由此可以推断，select * from mytbl;查询的是从库。

使用master节点访问一下

[root@master ~]# mysql -uroot -p000000 -e "use testdb;select * from mytbl;"
+------+--------+
| id   | name   |
+------+--------+
|    1 | csq    |
|    1 | master |

使用slave节点访问一下

[root@slave ~]# mysql -uroot -p000000 -e "use testdb;select * from mytbl;"
+------+-------+
| id   | name  |
+------+-------+
|    1 | csq   |
|    1 | slave |
+------+-------+

至此 Ansible部署主从数据库+读写分离结束