写在前面
当mysql数据量不大且达到读写瓶颈的时候，读的性能消耗远大于写，我们可以将读和写分离开。本实例采用docker容器搭建，通过mycat中间件做分发
准备mysql主从服务
- 准备mysql容器
$ docker pull mysql:5.7
- 创建主从数据映射目录
// 数据和配置不至于丢失
/usr/local/docker_app/mysql/master/conf.d
/usr/local/docker_app/mysql/slave/conf.d
- 创建master配置文件
/usr/local/docker_app/mysql/master/conf.d/my.cnf
[mysqld]
log-bin=master-bin
server-id=1
- 创建slave配置文件
/usr/local/docker_app/mysql/slave/conf.d/my.cnf
[mysqld]
log-bin=slave-bin
server-id=2
- 启动master服务
$ docker run -d --name mysql-master \
-p 3306:3306 \
-v /usr/local/docker_app/mysql/master/conf.d/data:/var/lib/mysql \
-v /usr/local/docker_app/mysql/master/conf.d:/etc/mysql/conf.d \
-e MYSQL_ROOT_PASSWORD=root \
-d mysql:5.7
- 启动slave服务
$ docker run -d --name mysql-slave \
-p 3307:3306 \
-v /usr/local/docker_app/mysql/slave/conf.d/data:/var/lib/mysql \
-v /usr/local/docker_app/mysql/slave/conf.d:/etc/mysql/conf.d \
-e MYSQL_ROOT_PASSWORD=root \
-d mysql:5.7
- 进入容器修改master slave的读写权限
# 进入容器shell
$ docker exec -it mysql-master /bin/sh
// mysql shell
// 用户名：root
// 密码：root
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
- 进入mysql-master查看master状态
// mysql shell
show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| master-bin.000003 | 154 | | | |
+------------------+----------+--------------+------------------+-------------------+
- 获取master容器的host
$ docker inspect --format='{{.NetworkSettings.IPAddress}}' mysql-master
- 进入mysql-slave关联主从模式
// mysql shell
change master to master_host='172.17.0.2', master_user='root',master_password='root', master_log_file='master-bin.000003',master_log_pos=154;
// mysql shell
// 启用slave
start slave;
- 测试主从
在master创建testdb数据库，再到slave中查看是否存在testdb库，若存在则基本完成，若未成功检查binlog、master host、position是否正确；目前已经可以给前台使用，只不过要区分读写数据源，挺麻烦！
mycat中间件代理mysql
- 准备mycat镜像
// jre8
http://download.oracle.com/otn-pub/java/jdk/8u152-b16/aa0333dd3019491ca4f6ddbe78cdb6d0/server-jre-8u152-linux-x64.tar.gz
# Dockerfile
FROM debian:jessie
# install jre
COPY server-jre-8u152-linux-x64.tar.gz /usr/local/
RUN cd /usr/local && tar -zxvf server-jre-8u152-linux-x64.tar.gz && rm -f server-jre-8u152-linux-x64.tar.gz
ENV JAVA_HOME /usr/local/jdk1.8.0_152
ENV CLASSPATH ${JAVA_HOME}/lib/dt.jar:$JAVA_HOME/lib/tools.jar
ENV PATH $PATH:${JAVA_HOME}/bin
# install mycat
ADD http://dl.mycat.io/1.6-RELEASE/Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz /usr/local/
RUN cd /usr/local && tar -zxvf Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz && rm -f Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz
VOLUME /usr/local/mycat/conf
EXPOSE 8066 9066
CMD ["/usr/local/mycat/bin/mycat", "console"]
$ docker build -t mysql/mycat:1.6 .
- 创建mycat本地映射目录
/usr/local/docker_app/mycat/conf
/usr/local/docker_app/mycat/logs
- 解压mycat压缩包拷贝conf目录下文件到
/usr/local/docker_app/mycat/conf - 修改
/usr/local/docker_app/mycat/conf/schema.xml文件
<!-- 第一种方案 master挂了slave不可用 -->
<?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>
<!-- testdb为库名称 -->
<dataNode name="dn1" dataHost="localhost1" database="testdb" />
<dataHost name="localhost1" maxCon="1000" minCon="10" balance="1"
writeType="0" dbType="mysql" dbDriver="native" switchType="0" slaveThreshold="100">
<heartbeat>select user()</heartbeat>
<!-- can have multi write hosts -->
<writeHost host="mysql-master" url="172.17.0.2:3306" user="root" password="root">
<!-- can have multi read hosts -->
<readHost host="mysql-slave" url="172.17.0.3:3306" user="root" password="root" />
</writeHost>
</dataHost>
</mycat:schema>
<!-- 第二种方案，master挂slave可自动切换，重启也会使用slave，原master为旧数据 -->
<?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>
<!-- testdb为库名称 -->
<dataNode name="dn1" dataHost="localhost1" database="testdb" />
<dataHost name="localhost1" maxCon="1000" minCon="10" balance="1"
writeType="0" dbType="mysql" dbDriver="native" switchType="0" slaveThreshold="100">
<heartbeat>select user()</heartbeat>
<!-- can have multi write hosts -->
<writeHost host="mysql-master" url="172.17.0.2:3306" user="root" password="root"></writeHost>
<writeHost host="mysql-slave" url="172.17.0.3:3306" user="root" password="root"></writeHost>
</dataHost>
</mycat:schema>
- 修改/usr/local/docker_app/mycat/conf/server.xml文件
<user name="root">
<property name="password">root</property>
<!-- 对应上面schema名称 -->
<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">user</property>
<property name="schemas">TESTDB</property>
<property name="readOnly">true</property>
</user>
- 启动mycat容器
# 8066：mysql协议端口
# 9066：管理端口
$ docker run -d --name mysql-mycat \
-v /usr/local/docker_app/mycat/conf:/usr/local/mycat/conf \
-v /usr/local/docker_app/mycat/logs:/usr/local/mycat/logs \
-p 8066:8066 -p 9066:9066 mysql/mycat:1.6
- mycat测试
mysql工具链接mycat的8066端口，创建表插入数据之后，分别查看master和slave端数据变化；若不成功，查看mycat配置是否正确，注意ip地址为docker容器内部ip
写在最后
初次实验，若有误解欢迎指正！
