MySQL-分布式架构-MyCAT
2019-11-26
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1、MyCAT基础架构准备
MyCAT基础架构图
摘自oldguo
1.1 MyCAT基础架构准备
1.1.1 环境准备：
两台虚拟机 db01（10.0.0.51） db02（10.0.0.52） 每台创建四个MySQL实例：3307 3308 3309 3310 1.1.2 删除历史环境：
pkill mysqld rm -rf /data/330* mv /etc/my.cnf /etc/my.cnf.bak
1.1.3 创建相关目录初始化数据
mkdir /data/33{07..10}/data -p
mysqld --initialize-insecure --user=mysql --datadir=/data/3307/data --basedir=/Application/mysql
mysqld --initialize-insecure --user=mysql --datadir=/data/3308/data --basedir=/application/mysql
mysqld --initialize-insecure --user=mysql --datadir=/data/3309/data --basedir=/application/mysql
mysqld --initialize-insecure --user=mysql --datadir=/data/3310/data --basedir=/application/mysql
1.1.4 准备配置文件和启动脚本
========db01============== cat >/data/3307/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3307/data socket=/data/3307/mysql.sock port=3307 log-error=/data/3307/mysql.log log_bin=/data/3307/mysql-bin binlog_format=row skip-name-resolve server-id=7 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3308/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3308/data port=3308 socket=/data/3308/mysql.sock log-error=/data/3308/mysql.log log_bin=/data/3308/mysql-bin binlog_format=row skip-name-resolve server-id=8 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3309/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3309/data socket=/data/3309/mysql.sock port=3309 log-error=/data/3309/mysql.log log_bin=/data/3309/mysql-bin binlog_format=row skip-name-resolve server-id=9 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3310/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3310/data socket=/data/3310/mysql.sock port=3310 log-error=/data/3310/mysql.log log_bin=/data/3310/mysql-bin binlog_format=row skip-name-resolve server-id=10 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/etc/systemd/system/mysqld3307.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3307/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3308.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3308/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3309.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3309/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3310.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf LimitNOFILE = 5000 EOF ========db02=============== cat >/data/3307/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3307/data socket=/data/3307/mysql.sock port=3307 log-error=/data/3307/mysql.log log_bin=/data/3307/mysql-bin binlog_format=row skip-name-resolve server-id=17 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3308/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3308/data port=3308 socket=/data/3308/mysql.sock log-error=/data/3308/mysql.log log_bin=/data/3308/mysql-bin binlog_format=row skip-name-resolve server-id=18 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3309/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3309/data socket=/data/3309/mysql.sock port=3309 log-error=/data/3309/mysql.log log_bin=/data/3309/mysql-bin binlog_format=row skip-name-resolve server-id=19 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3310/my.cnf<<EOF [mysqld] basedir=/application/mysql datadir=/data/3310/data socket=/data/3310/mysql.sock port=3310 log-error=/data/3310/mysql.log log_bin=/data/3310/mysql-bin binlog_format=row skip-name-resolve server-id=20 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/etc/systemd/system/mysqld3307.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3307/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3308.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3308/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3309.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3309/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3310.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf LimitNOFILE = 5000 EOF
1.1.5 修改权限，启动多实例
chown -R mysql.mysql /data/* systemctl start mysqld3307 systemctl start mysqld3308 systemctl start mysqld3309 systemctl start mysqld3310 mysql -S /data/3307/mysql.sock -e "show variables like 'server_id'" mysql -S /data/3308/mysql.sock -e "show variables like 'server_id'" mysql -S /data/3309/mysql.sock -e "show variables like 'server_id'" mysql -S /data/3310/mysql.sock -e "show variables like 'server_id'"
1.1.6 节点主从规划 箭头指向谁是主库
10.0.0.51:3307 <-----> 10.0.0.52:3307 10.0.0.51:3309 ------> 10.0.0.51:3307 10.0.0.52:3309 ------> 10.0.0.52:3307 10.0.0.52:3308 <-----> 10.0.0.51:3308 10.0.0.52:3310 -----> 10.0.0.52:3308 10.0.0.51:3310 -----> 10.0.0.51:3308
1.1.7 分片规划
shard1： Master：10.0.0.51:3307 slave1：10.0.0.51:3309 Standby Master：10.0.0.52:3307 slave2：10.0.0.52:3309 shard2： Master：10.0.0.52:3308 slave1：10.0.0.52:3310 Standby Master：10.0.0.51:3308 slave2：10.0.0.51:3310
1.1.8 开始配置
shard1 10.0.0.51:3307 <-----> 10.0.0.52:3307 db02 mysql -S /data/3307/mysql.sock -e "grant replication slave on *.* to repl@'10.0.0.%' identified by '123';" mysql -S /data/3307/mysql.sock -e "grant all on *.* to root@'10.0.0.%' identified by '123' with grant option;" db01 mysql -S /data/3307/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSword='123';" mysql -S /data/3307/mysql.sock -e "start slave;" mysql -S /data/3307/mysql.sock -e "show slave statusG" db02 mysql -S /data/3307/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3307/mysql.sock -e "start slave;" mysql -S /data/3307/mysql.sock -e "show slave statusG" 10.0.0.51:3309 ------> 10.0.0.51:3307 db01 mysql -S /data/3309/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3309/mysql.sock -e "start slave;" mysql -S /data/3309/mysql.sock -e "show slave statusG" 10.0.0.52:3309 ------> 10.0.0.52:3307 db02 mysql -S /data/3309/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3309/mysql.sock -e "start slave;" mysql -S /data/3309/mysql.sock -e "show slave statusG" shard2 10.0.0.52:3308 <-----> 10.0.0.51:3308 db01 mysql -S /data/3308/mysql.sock -e "grant replication slave on *.* to repl@'10.0.0.%' identified by '123';" mysql -S /data/3308/mysql.sock -e "grant all on *.* to root@'10.0.0.%' identified by '123' with grant option;" db02 mysql -S /data/3308/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3308/mysql.sock -e "start slave;" mysql -S /data/3308/mysql.sock -e "show slave statusG" db01 mysql -S /data/3308/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3308/mysql.sock -e "start slave;" mysql -S /data/3308/mysql.sock -e "show slave statusG" 10.0.0.52:3310 -----> 10.0.0.52:3308 db02 mysql -S /data/3310/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3310/mysql.sock -e "start slave;" mysql -S /data/3310/mysql.sock -e "show slave statusG" 10.0.0.51:3310 -----> 10.0.0.51:3308 db01 mysql -S /data/3310/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3310/mysql.sock -e "start slave;" mysql -S /data/3310/mysql.sock -e "show slave statusG"
1.1.9 检测主从状态
mysql -S /data/3307/mysql.sock -e "show slave statusG"|grep Running: mysql -S /data/3308/mysql.sock -e "show slave statusG"|grep Running: mysql -S /data/3309/mysql.sock -e "show slave statusG"|grep Running: mysql -S /data/3310/mysql.sock -e "show slave statusG"|grep Running:
1.1.10 如果中间出现错误，在每个节点进行执行以下命令(2.9 状态正确,忽略此步骤)
mysql -S /data/3307/mysql.sock -e "stop slave; reset slave all;" mysql -S /data/3308/mysql.sock -e "stop slave; reset slave all;" mysql -S /data/3309/mysql.sock -e "stop slave; reset slave all;" mysql -S /data/3310/mysql.sock -e "stop slave; reset slave all;"
1.2 Mycat的安装
MySQL分布式架构介绍：
1.2.1 安装JAVA环境
yum install -y java
1.2.2 上传到/application 并解压
略官网：http://www.mycat.io/
1.2.3 配置文件介绍
conf: schema.xml 主配置文件（读写分离、高可用、分布式策略定制、节点控制） server.xml mycat软件本身相关的配置 rule.xml 分片规则配置文件,记录分片规则列表、使用方法等 xxxx.txt 分片参数功能有关 logs目录: wrapper.log ---->mycat启动日志 mycat.log ---->mycat详细工作日志
1.2.4 启动mycat
[root@db02 ~]# vim /etc/profile export PATH=/application/mycat/bin:$PATH [root@db02 ~]# source /etc/profile [root@db02 ~]# mycat start [root@db02 ~]# mysql -uroot -p123456 -h 10.0.0.52 -P8066 1.3 测试数据准备
## db01: mysql -S /data/3307/mysql.sock grant all on *.* to root@'10.0.0.%' identified by '123'; source /root/world.sql mysql -S /data/3308/mysql.sock grant all on *.* to root@'10.0.0.%' identified by '123'; source /root/world.sql
1.4 核心配置文件使用介绍(schema.xml)
（1）逻辑库定义 <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="sh1"> </schema> （2）数据节点定义 <dataNode name="sh1" dataHost="oldguo1" database= "world" /> （3）数据主机定义 <dataHost name="oldguo1" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"> <heartbeat>select user()</heartbeat> <writeHost host="db1" url="10.0.0.51:3307" user="root" password="123"> <readHost host="db2" url="10.0.0.51:3309" user="root" password="123" /> </writeHost> </dataHost>
1.5 Mycat实现读写分离功能
（1）配置conf文件--schema.xml
[root@db02 /application/mycat/conf]# cat schema.xml <?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="sh1"> </schema> <dataNode name="sh1" dataHost="oldguo1" database= "world" /> <dataHost name="oldguo1" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"> <heartbeat>select user()</heartbeat> <writeHost host="db1" url="10.0.0.51:3307" user="root" password="123"> <readHost host="db2" url="10.0.0.51:3309" user="root" password="123" /> </writeHost> </dataHost> </mycat:schema>
（2）Mycat重启生效:
mycat restart
（3）模拟测试
[root@db02 /application/mycat/conf]# mysql -uroot -p123456 -h 10.0.0.52 -P8066 mysql> select @@server_id; ----模拟查询 mysql> begin; select @@server_id;commit; ---模拟写入
1.6 读写分离+高可用功能
[root@db01 conf]# mv schema.xml schema.xml.rw [root@db01 conf]# vim schema.xml <?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="sh1"> </schema> <dataNode name="sh1" dataHost="oldguo1" database= "world" /> <dataHost name="oldguo1" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"> <heartbeat>select user()</heartbeat> <writeHost host="db1" url="10.0.0.51:3307" user="root" password="123"> <readHost host="db2" url="10.0.0.51:3309" user="root" password="123" /> </writeHost> <writeHost host="db3" url="10.0.0.52:3307" user="root" password="123"> <readHost host="db4" url="10.0.0.52:3309" user="root" password="123" /> </writeHost> </dataHost> </mycat:schema> 真正的 writehost：负责写操作的writehost standby writeHost ：和readhost一样，只提供读服务 当写节点宕机后，后面跟的readhost也不提供服务，这时候standby的writehost就提供写服务， 后面跟的readhost提供读服务 。 测试： mysql -uroot -p123456 -h 127.0.0.1 -P 8066 show variables like 'server_id'; 读写分离测试 mysql -uroot -p -h 127.0.0.1 -P8066 show variables like 'server_id'; show variables like 'server_id'; show variables like 'server_id'; begin; show variables like 'server_id'; 对db01 3307节点进行关闭和启动,测试读写操作
1.7 配置中的属性介绍
1.7.1 balance属性
负载均衡类型，目前的取值有3种： (1) balance="0", 不开启读写分离机制，所有读操作都发送到当前可用的writeHost上。 (2) balance="1"，全部的readHost与standby writeHost参与select语句的负载均衡，简单的说， 当双主双从模式(M1->S1，M2->S2，并且M1与 M2互为主备)，正常情况下，M2,S1,S2都参与select语句的负载均衡。 (3) balance="2"，所有读操作都随机的在writeHost、readhost上分发。 1.7.2 writeType属性
负载均衡类型，目前的取值有2种： （1）writeType="0", 所有写操作发送到配置的第一个writeHost， 第一个挂了切到还生存的第二个writeHost，重新启动后已切换后的为主，切换记录在配置文件中:dnindex.properties . （2）writeType=“1”，所有写操作都随机的发送到配置的writeHost，但不推荐使用
1.7.3 switchType属性
-1 表示不自动切换 1 默认值，自动切换 2 基于MySQL主从同步的状态决定是否切换 ，心跳语句为 show slave status 1.7.4 datahost其他配置
<dataHost name="localhost1" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"> maxCon="1000"：最大的并发连接数 minCon="10" ：mycat在启动之后，会在后端节点上自动开启的连接线程 tempReadHostAvailable="1" 这个一主一从时（1个writehost，1个readhost时），可以开启这个参数，如果2个writehost，2个readhost时 <heartbeat>select user()</heartbeat> 监测心跳 1.8 垂直分表
1.8.1 修改schema.xml配置文件
mv schema.xml schema.xml.ha vim schema.xml <?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="sh1"> <table name="user" dataNode="sh1"/> <table name="order_t" dataNode="sh2"/> </schema> <dataNode name="sh1" dataHost="oldguo1" database= "taobao" /> <dataNode name="sh2" dataHost="oldguo2" database= "taobao" /> <dataHost name="oldguo1" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"> <heartbeat>select user()</heartbeat> <writeHost host="db1" url="10.0.0.51:3307" user="root" password="123"> <readHost host="db2" url="10.0.0.51:3309" user="root" password="123" /> </writeHost> <writeHost host="db3" url="10.0.0.52:3307" user="root" password="123"> <readHost host="db4" url="10.0.0.52:3309" user="root" password="123" /> </writeHost> </dataHost> <dataHost name="oldguo2" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"> <heartbeat>select user()</heartbeat> <writeHost host="db1" url="10.0.0.51:3308" user="root" password="123"> <readHost host="db2" url="10.0.0.51:3310" user="root" password="123" /> </writeHost> <writeHost host="db3" url="10.0.0.52:3308" user="root" password="123"> <readHost host="db4" url="10.0.0.52:3310" user="root" password="123" /> </writeHost> </dataHost> </mycat:schema>
1.8.2 创建测试库和表:
mysql -S /data/3307/mysql.sock -e "create database taobao charset utf8;" mysql -S /data/3308/mysql.sock -e "create database taobao charset utf8;" mysql -S /data/3307/mysql.sock -e "use taobao;create table user(id int,name varchar(20))"; mysql -S /data/3308/mysql.sock -e "use taobao;create table order_t(id int,name varchar(20))"
1.8.3 重启MyCat
mycat restart
1.8.4 进入MyCat测试，添加数据测试
mysql -uroot -p123456 -h 10.0.0.51 -P 8066 --这里的ip地址是MyCat安装的那个虚拟机，就是哪个虚拟机的ip地址 mysql -S /data/3307/mysql.sock -e "use taobao;show tables;" mysql -S /data/3308/mysql.sock -e "use taobao;show tables;" 1.9 MyCAT核心特性——分片（水平拆分）
分片：对一个"bigtable"，比如说t3表 (1)行数非常多，800w (2)访问非常频繁 分片的目的： （1）将大数据量进行分布存储 （2）提供均衡的访问路由 分片策略： 范围 range 800w 1-400w 400w01-800w 取模 mod 取余数 枚举 哈希 hash 时间 流水 优化关联查询 全局表 ER分片 1.9.1 范围分片
（1）范围分片参数配置
比如说t3表 (1)行数非常多，2000w（1-1000w:sh1 1000w01-2000w:sh2） (2)访问非常频繁，用户访问较离散 cp schema.xml schema.xml.1 ==========vim schema.xml <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="sh1"> <table name="t3" dataNode="sh1,sh2" rule="auto-sharding-long" /> </schema> <dataNode name="sh1" dataHost="oldguo1" database= "taobao" /> <dataNode name="sh2" dataHost="oldguo2" database= "taobao" /> ===========vim rule.xml <tableRule name="auto-sharding-long"> <rule> <columns>id</columns> <algorithm>rang-long</algorithm> </rule> <function name="rang-long" class="io.mycat.route.function.AutoPartitionByLong"> <property name="mapFile">autopartition-long.txt</property> </function> ===========vim autopartition-long.txt 0-10=0 11-20=1
（2）创建测试表：
mysql -S /data/3307/mysql.sock -e "use taobao;create table t3 (id int not null primary key auto_increment,name varchar(20) not null);" mysql -S /data/3308/mysql.sock -e "use taobao;create table t3 (id int not null primary key auto_increment,name varchar(20) not null);"
（3）重启mycat------>mycat restart
（4）登录mycat插入数据
mysql -uroot -p123456 -h 127.0.0.1 -P 8066 insert into t3(id,name) values(1,'a'); insert into t3(id,name) values(2,'b'); insert into t3(id,name) values(3,'c'); insert into t3(id,name) values(4,'d'); insert into t3(id,name) values(11,'aa'); insert into t3(id,name) values(12,'bb'); insert into t3(id,name) values(13,'cc'); insert into t3(id,name) values(14,'dd');
（5）分别登入后端节点测试
mysql -S /data/3307/mysql.sock -e "use taobao;select * from t5;" mysql -S /data/3308/mysql.sock -e "use taobao;select * from t5;"
1.9.2 取模分片（mod-long）
取余分片方式：分片键（一个列）与节点数量进行取余，得到余数，将数据写入对应节点
（1）取模分片参数配置
=======vim schema.xml <table name="t4" dataNode="sh1,sh2" rule="mod-long" /> ========vim rule.xml <tableRule name="mod-long"> <rule> <columns>id</columns> <algorithm>mod-long</algorithm> </rule> </tableRule> <function name="mod-long" class="io.mycat.route.function.PartitionByMod"> <!-- how many data nodes --> <property name="count">2</property> </function>
（2）创建测试表：
mysql -S /data/3307/mysql.sock -e "use taobao;create table t4 (id int not null primary key auto_increment,name varchar(20) not null);" mysql -S /data/3308/mysql.sock -e "use taobao;create table t4 (id int not null primary key auto_increment,name varchar(20) not null);"
（3）重启mycat
mycat restart
（4）模拟数据测试：
mysql -uroot -p123456 -h10.0.0.52 -P8066 use TESTDB insert into t4(id,name) values(1,'a'); insert into t4(id,name) values(2,'b'); insert into t4(id,name) values(3,'c'); insert into t4(id,name) values(4,'d');
（5）分别登录后端节点查询数据
mysql -S /data/3307/mysql.sock -e "use taobao;select * from t4;" mysql -S /data/3308/mysql.sock -e "use taobao;select * from t4;"
1.9.3 枚举分片
t5 表 id name telnum 1 bj 1212 2 sh 22222 3 bj 3333 4 sh 44444 5 bj 5555 （1）枚举分片参数配置
=====vim schema.xml <table name="t5" dataNode="sh1,sh2" rule="sharding-by-intfile" /> =====vim rule.xml <tableRule name="sharding-by-intfile"> <rule> <columns>name</columns> <algorithm>hash-int</algorithm> </rule> </tableRule> <function name="hash-int" class="org.opencloudb.route.function.PartitionByFileMap"> <property name="mapFile">partition-hash-int.txt</property> <property name="type">1</property> </function> ======partition-hash-int.txt 配置： bj=0 sh=1 DEFAULT_NODE=1 columns 标识将要分片的表字段，algorithm 分片函数， 其中分片函数配置中，mapFile标识配置文件名称
（2）准备测试环境
mysql -S /data/3307/mysql.sock -e "use taobao;create table t5 (id int not null primary key auto_increment,name varchar(20) not null);" mysql -S /data/3308/mysql.sock -e "use taobao;create table t5 (id int not null primary key auto_increment,name varchar(20) not null);"
（3）重启mycat
mycat restart （4）模拟数据测试
mysql -uroot -p123456 -h10.0.0.52 -P8066 use TESTDB insert into t5(id,name) values(1,'bj'); insert into t5(id,name) values(2,'sh'); insert into t5(id,name) values(3,'bj'); insert into t5(id,name) values(4,'sh'); insert into t5(id,name) values(5,'tj'); （5）分别登录后端节点查询数据
mysql -S /data/3307/mysql.sock -e "use taobao;select * from t5;" mysql -S /data/3308/mysql.sock -e "use taobao;select * from t5;"
1.9.4 Mycat全局表
a b c d join t select t1.name ,t.x from t1 join t select t2.name ,t.x from t2 join t select t3.name ,t.x from t3 join t 使用场景： 如果你的业务中有些数据类似于数据字典，比如配置文件的配置， 常用业务的配置或者数据量不大很少变动的表，这些表往往不是特别大， 而且大部分的业务场景都会用到，那么这种表适合于Mycat全局表，无须对数据进行切分， 要在所有的分片上保存一份数据即可，Mycat 在Join操作中，业务表与全局表进行Join聚合会优先选择相同分片内的全局表join， 避免跨库Join，在进行数据插入操作时，mycat将把数据分发到全局表对应的所有分片执行，在进行数据读取时候将会随机获取一个节点读取数据。 （1）Mycat全局表参数配置
=====vim schema.xml <table name="t_area" primaryKey="id" type="global" dataNode="sh1,sh2" />
（2）后端数据准备
mysql -S /data/3307/mysql.sock -e "use taobao;create table t_area (id int not null primary key auto_increment,name varchar(20) not null);" mysql -S /data/3308/mysql.sock -e "use taobao;create table t_area (id int not null primary key auto_increment,name varchar(20) not null);"
（3）重启mycat
mycat restart
（4）模拟数据测试：
mysql -uroot -p123456 -h10.0.0.52 -P8066 use TESTDB insert into t_area(id,name) values(1,'a'); insert into t_area(id,name) values(2,'b'); insert into t_area(id,name) values(3,'c'); insert into t_area(id,name) values(4,'d');
（5）分别登录后端节点查询数据
mysql -S /data/3307/mysql.sock -e "use taobao;select * from t_area;" mysql -S /data/3308/mysql.sock -e "use taobao;select * from t_area;" 2.9.5 ER分片
有一类业务，例如商品（goods）跟商品明细（goods_detail）,明细表会依赖于商品，也就是说会存在表的主 从关系，这类似业务的切分可以抽象出合适的切分规则，比如根据商品 ID 切分，总之部分业务总会可以抽象出父子关系的表。这类表适用于 ER 分片表，子表的记录与所关联的父表记录存放在同一个数据分片上，避免数据 Join 跨库操作。 goods join goods_detail on goods.id=goods_detail.good_id （1）ER分片参数配置
=====vim schema.xml <table name="goods" dataNode="sh1,sh2" rule="mod-long"> <childTable name="goods_detail" joinKey="goods_id" parentKey="id" /> </table>
（2）后端数据表准备
mysql -S /data/3307/mysql.sock -e "use taobao;create table goods (id int not null primary key auto_increment,name varchar(20) not null);" mysql -S /data/3308/mysql.sock -e "use taobao;create table goods (id int not null primary key auto_increment,name varchar(20) not null);" mysql -S /data/3307/mysql.sock -e "use taobao;create table goods_detail (detail_id int not null primary key auto_increment,name varchar(20) not null,goods_id int not null);" mysql -S /data/3308/mysql.sock -e "use taobao;create table goods_detail (detail_id int not null primary key auto_increment,name varchar(20) not null,goods_id int not null);"
（3）重启mycat
mycat restart
（4）模拟数据测试：
mysql -uroot -p123456 -h10.0.0.51 -P8066 ===========goods use TESTDB insert into goods(id,name) values(1,'dn'); insert into goods(id,name) values(2,'sj'); insert into goods(id,name) values(3,'yf'); insert into goods(id,name) values(4,'bk'); ===========goods_detail use TESTDB insert into goods_detail(detail_id,name,goods_id) values(1,'电脑',1); insert into goods_detail(detail_id,name,goods_id) values(2,'500元',1); insert into goods_detail(detail_id,name,goods_id) values(3,'手机',2); insert into goods_detail(detail_id,name,goods_id) values(4,'红色',2); insert into goods_detail(detail_id,name,goods_id) values(5,'衣服',3); insert into goods_detail(detail_id,name,goods_id) values(6,'s码',3); insert into goods_detail(detail_id,name,goods_id) values(7,'书籍',4); insert into goods_detail(detail_id,name,goods_id) values(8,'linux方向',4);
（5）分别登录后端节点查询数据
mysql -S /data/3307/mysql.sock -e "use taobao;select * from goods;select * from goods_detail;" mysql -S /data/3308/mysql.sock -e "use taobao;select * from goods;select * from goods_detail;" [root@db01 ~]# mysql -S /data/3307/mysql.sock -e "use taobao;select * from goods;select * from goods_detail;" +----+------+ | id | name | +----+------+ | 2 | sj | | 4 | bk | +----+------+ +-----------+-------------+----------+ | detail_id | name | goods_id | +-----------+-------------+----------+ | 3 | 手机 | 2 | | 4 | 红色 | 2 | | 7 | 书籍 | 4 | | 8 | Linux方向 | 4 | +-----------+-------------+----------+ [root@db01 ~]# mysql -S /data/3308/mysql.sock -e "use taobao;select * from goods;select * from goods_detail;" +----+------+ | id | name | +----+------+ | 1 | dn | | 3 | yf | +----+------+ +-----------+--------+----------+ | detail_id | name | goods_id | +-----------+--------+----------+ | 1 | 电脑 | 1 | | 2 | 500元 | 1 | | 5 | 衣服 | 3 | | 6 | s码 | 3 | +-----------+--------+----------+ [root@db01 ~]#
原文：https://www.jianshu.com/p/7ec2847583d4
作者：文娟_狼剩
来源：简书
