MySQL之九---分布式架构（Mycat/DBLE）

MyCAT基础架构图

双主双从结构

MyCAT基础架构准备

准备环境

 环境准备：
 两台虚拟机 db01 db02
 每台创建四个mysql实例：3307 3308 3309 3310

删除历史环境

 pkill mysqld
 rm -rf /data/330*
 \mv /etc/my.cnf /etc/my.cnf.bak

初始化数据

 mkdir /data/33{07..10}/data -p
 mysqld --initialize-insecure  --user=mysql --datadir=/data/3307/data --basedir=/usr/local/mysql
 mysqld --initialize-insecure  --user=mysql --datadir=/data/3308/data --basedir=/usr/local/mysql
 mysqld --initialize-insecure  --user=mysql --datadir=/data/3309/data --basedir=/usr/local/mysql
 mysqld --initialize-insecure  --user=mysql --datadir=/data/3310/data --basedir=/usr/local/mysql

配置文件

========db01==============

 cat >/data/3307/my.cnf<<EOF
 [mysqld]
 basedir=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf
LimitNOFILE = 5000
EOF

========db02===============

 cat >/data/3307/my.cnf<<EOF
 [mysqld]
 basedir=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/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=/usr/local/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf
 LimitNOFILE = 5000
EOF

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'"

配置主从环境

 shard1
 10.0.0.51:3307 <-----> 10.0.0.52:3307
 # db02
 mysql  -S /data/3307/mysql.sock -e "create user repl@'10.0.0.%' identified with mysql_native_password by '123'; grant replication slave on *.* to repl@'10.0.0.%'; "
 mysql  -S /data/3307/mysql.sock -e "create user root@'10.0.0.%' identified with mysql_native_password by '123'; grant all  on *.* to root@'10.0.0.%'; "
 # 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 status \G"|grep Running
 # 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 status\G" |grep Running
 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 status\G"|grep Running
 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 status\G"|grep Running
 ====================================================================
 ​
 ​
 # shard2
 ## 10.0.0.52:3308 <-----> 10.0.0.51:3308
 # db01
 mysql  -S /data/3308/mysql.sock -e "create user repl@'10.0.0.%' identified with mysql_native_password by '123'; grant replication slave on *.* to repl@'10.0.0.%';"
 mysql  -S /data/3308/mysql.sock -e "create user root@'10.0.0.%' identified with mysql_native_password by '123'; grant all  on *.* to root@'10.0.0.%'; "
 ​
 # 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 status\G" |grep Running
 # 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 status\G"|grep Running
 ## 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 status\G" |grep Running
 ##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 status\G"|grep Running

检测主从状态

 mysql -S /data/3307/mysql.sock -e "show slave status\G"|grep Yes
 mysql -S /data/3308/mysql.sock -e "show slave status\G"|grep Yes
 mysql -S /data/3309/mysql.sock -e "show slave status\G"|grep Yes
 mysql -S /data/3310/mysql.sock -e "show slave status\G"|grep Yes

注：如果中间出现错误，在每个节点进行执行以下命令，从配置主从环境开始执行 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;"

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

MySQL分布式架构介绍

1. schema拆分及业务分库
2. 垂直拆分-分库分表
3. 水平拆分-分片

企业代表产品

 360 Atlas-Sharding
 Alibaba  cobar 
 Mycat
 TDDL
 Heisenberg
 Oceanus
 Vitess
 OneProxy 
 DRDS

MyCAT安装

开源组织和社区开发人员，在淘宝cobar(TDDL)基础上二次开发，Mycat后来被爱可生改写成了DBLE

安装Java运行环境

 yum install -y java

下载

http://dl.mycat.org.cn/1.6.7.4/

http://dl.mycat.org.cn/1.6.7.4/Mycat-server-1.6.7.4-release/Mycat-server-1.6.7.4-release-20200105164103-linux.tar.gz

解压文件

 [root@db02 opt]#rz
 [root@db02 opt]# tar xf Mycat-server-1.6.7.4-release-20200105164103-linux_.tar.gz

软件目录结构

 ls
 bin  catlet  conf  lib  logs  version.txt

启动和连接

 配置环境变量

 [root@db02 opt]#vim /etc/profile
 export PATH=/opt/mycat/bin:$PATH
 [root@db02 opt]#source /etc/profile

 启动

 [root@db02 opt]#mycat start

 连接mycat：    

 [root@db02 opt]#mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password

8.0之前[root@db02 opt]#mysql -uroot -p123456 -h10.0.0.52 -P8066

配置文件介绍

 bin 目录
 程序目录
 conf 
 配置文件目录
 schema.xml
 主配置文件：节点信息、读写分离、高可用设置、调用分片策略..
 rule.xml
 分片策略的定义、功能、使用用方法
 server.xml
 mycat服务有关配置： 用户、网络、权限、策略、资源...
 xx.txt文件
 分片参数定义文件
 log4j2.xml
 Mycat 相关日志记录配置
 logs
 wrapper.log: 启动日志  
 mycat.log : 工作日志

应用环境准备

用户创建及数据库导入

 schema.xml配置文件结构

 [root@db02 conf]# cd /opt/mycat/conf/
 [root@db02 conf]#mv schema.xml schema.xml.bak
 [root@db02 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="dn1">
 </schema>
     <dataNode name="dn1" dataHost="localhost1" database= "world" />
     <dataHost name="localhost1" 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>


 ########################测试环境准备

 [root@db02 conf]# mysql -S /data/3307/mysql.sock -e  "source /root/world.sql"
 [root@db02 conf]# mysql -S /data/3308/mysql.sock -e  "source /root/world.sql"
 [root@db02 conf]# mycat restart  重启mycat
     
 ######################## 读写分离测试    
  # 测试读

 mysql -uroot -p123456 -h 10.0.0.52 -P8066 --default-auth=mysql_native_password  -e "select @@server_id;"
  mysql: [Warning] Using a password on the command line interface can be insecure.
 +-------------+
 | @@server_id |
 +-------------+
 |           9 |
 +-------------+
  # 测试写
 mysql -uroot -p123456 -h 10.0.0.52 -P8066 --default-auth=mysql_native_password  -e "begin ; select @@server_id;commit;"
 mysql: [Warning] Using a password on the command line interface can be insecure.
 +-------------+
 | @@server_id |
 +-------------+
 |           7 |
 +-------------+

         
 ############################总结： 
 以上案例实现了1主1从的读写分离功能，写操作落到主库，读操作落到从库.如果主库宕机，从库不能在继续提供服务了。

配置文件详细介绍

逻辑库：schema

 <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1">
 </schema>

数据节点:datanode

 <dataNode name="dn1" dataHost="localhost1" database= "world" />

数据主机：datahost(w和r)

 <dataHost name="localhost1" 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="10.0.0.52:3309" user="root" password="123" />
     </writeHost>
     </dataHost>

配置读写分离及高可用

 [root@db02 conf]# mv schema.x

 [root@db02 conf]# mv schema.xml schema.xml.rw
 [root@db02 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>

ml schema.xml.rw
 [root@db02 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

重启

[root@db02 conf]#mycat restart

测试读(三读）

 [root@db02 conf]# mysql -uroot -p123456 -h 10.0.0.52 -P8066 --default-auth=mysql_native_password  -e "select @@server_id;"
 +-------------+
 | @@server_id |
 +-------------+
 |          19 |
 +-------------+
 +-------------+
 | @@server_id |
 +-------------+
 |          17 |
 +-------------+
 +-------------+
 | @@server_id |
 +-------------+
 |           9 |
 +-------------+
​

测试写（一写）

 [root@db02 conf]# mysql -uroot -p123456 -h 10.0.0.52 -P8066 --default-auth=mysql_native_password  -e "begin ; select @@server_id;commit;"
 +-------------+
 | @@server_id |
 +-------------+
 |           7 |
 +-------------+

测试高可用

[root@db01 ~]# systemctl stop mysqld3307
 [root@db02 conf]# mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password -e "select @@server_id;"
 +-------------+
 | @@server_id |
 +-------------+
 |          19 |
 +-------------+
 ​
 [root@db02 conf]# mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password -e "begin ; select @@server_id;commit;"
 +-------------+
 | @@server_id |
 +-------------+
 |          17 |
 +-------------+
 [root@db01 ~]# systemctl start  mysqld3307
 [root@db02 conf]# mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password -e "select @@server_id;"
   +-------------+
 | @@server_id |
 +-------------+
 |          19 |
 +-------------+
 +-------------+
 | @@server_id |
 +-------------+
 |           7 |
 +-------------+
 +-------------+
 | @@server_id |
 +-------------+
 |           9 |
 +-------------+
 ​
 [root@db02 conf]# mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password -e "begin ; select @@server_id;commit;"
  +-------------+
 | @@server_id |
 +-------------+
 |          17 |
 +-------------+

配置中的属性介绍:

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"，默认参数  三读一写  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。

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

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 

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

Mycat 分布式架构----垂直分表

 taobao库:   user （sh1），order_t(sh2)   ,others(sh3)
 [root@db02 conf]# mv  schema.xml  schema.xml.ha
 [root@db02 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">
         <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>

创建测试库和表

 [root@db02 conf]# mysql -S /data/3307/mysql.sock -e "create database taobao charset utf8;"
 [root@db02 conf]# mysql -S /data/3308/mysql.sock -e "create database taobao charset utf8;"
 [root@db02 conf]# mysql -S /data/3307/mysql.sock -e "use taobao;create table user(id int,name varchar(20))";
 [root@db02 conf]# mysql -S /data/3308/mysql.sock -e "use taobao;create table order_t(id int,name varchar(20))";

重启mycat

 [root@db02 conf]# mycat restart

mycat数据插入

 [root@db02 conf]# mysql -uroot -p123456 -h 10.0.0.52  -P 8066 --default-auth=mysql_native_password
 insert into user values(1,'a');
 insert into user values(2,'b');
 insert into user values(3,'c');
 commit;
 insert into order_t values(1,'x'),(2,'y');
 commit;
 show databases;
 use TESTDB;
 show tables
 select * from order_t;
 +------+------+
 | id   | name |
 +------+------+
 |    1 | x    |
 |    2 | y    |
 +------+------+
 2 rows in set (0.05 sec)
 ​
 mysql> select * from user;
 +------+------+
 | id   | name |
 +------+------+
 |    1 | a    |
 |    2 | b    |
 |    3 | c    |
 +------+------+

 [root@db02 conf]# mysql -S /data/3307/mysql.sock -e "show tables from taobao"
 +------------------+
 | Tables_in_taobao |
 +------------------+
 | user             |
 +------------------+
 [root@db02 conf]# mysql -S /data/3308/mysql.sock -e "show tables from taobao"
 +------------------+
 | Tables_in_taobao |
 +------------------+
 | order_t          |
 +------------------+
 [root@db02 conf]# mysql -S /data/3307/mysql.sock -e "select * from taobao.user"
 +------+------+
 | id   | name |
 +------+------+
 |    1 | a    |
 |    2 | b    |
 |    3 | c    |
 +------+------+
 [root@db02 conf]# mysql -S /data/3308/mysql.sock -e "select * from taobao.order_t"
 +------+------+
 | id   | name |
 +------+------+
 |    1 | x    |
 |    2 | y    |
 +------+------

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：
 几乎融合经典业务中大部分的分片策略。Mycat已经开发了相应算法，非常方便调用。
 范围分片 
 取模 
 枚举
 日期
 HASH
 等。
 分片键： 作为分片条件的列。

范围分片(range)

  比如说t3表
 行数非常多，2000w（1-1000w:sh1   1000w01-2000w:sh2）
 访问非常频繁，用户顺序访问较多

定制分片策略

 [root@db02 conf]#cp schema.xml schema.xml.1
 [root@db02 conf]#vim schema.xml
    <table name="user" dataNode="sh1"/>
  <table name="order_t" dataNode="sh2"/>
 下方添加：
    <table name="t3" dataNode="sh1,sh2" rule="auto-sharding-long" />
 </schema>

定义和使用分片策略

 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>

定义范围

 [root@db02 conf]#vim autopartition-long.txt
 0-10=0
 10-20=1

创建测试表

 [root@db02 conf]# 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);"
 [root@db02 conf]# 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);"

重启mycat并测试

 [root@db02 conf]# mycat restart
 [root@db02 conf]# mysql -uroot -p123456 -h 10.0.0.52 -P 8066  --default-auth=mysql_native_password
 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');
 mysql> show databases;
 +----------+
 | DATABASE |
 +----------+
 | TESTDB   |
 +----------+
 mysql> use TESTDB;
 mysql> show tables;
 +------------------+
 | Tables_in_taobao |
 +------------------+
 | order_t          |
 | t3               |
 | user             |
 +------------------+
 #####逻辑上合并
 mysql> select * from t3;
 +----+------+
 | id | name |
 +----+------+
 |  1 | a    |
 |  2 | b    |
 |  3 | c    |
 |  4 | d    |
 | 11 | aa   |
 | 12 | bb   |
 | 13 | cc   |
 | 14 | dd   |
 +----+------+
 ​
 ###物理上分开
 [root@db02 conf]# mysql -S /data/3308/mysql.sock  -e "select * from taobao.t3"
   +----+------+
 | id | name |
 +----+------+
 | 11 | aa   |
 | 12 | bb   |
 | 13 | cc   |
 | 14 | dd   |
 +----+------+
 [root@db02 conf]# mysql -S /data/3307/mysql.sock  -e "select * from taobao.t3"
   +----+------+
 | id | name |
 +----+------+
 |  1 | a    |
 |  2 | b    |
 |  3 | c    |
 |  4 | d    |

 +----+------+

取模分片（mod-long）

 1%3 1
 2%3 2
 3%3 0
 4%3 1
 5%3 2
 任何正整数数字和N（正整数）取模，得的值永远都是 0~N-1
 id % 分片数量取模
 N  % 5  =  0-4   idx

修改配置文件

 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
 [root@db02 conf]#vim schema.xml
 添加：....t3之后
    <table name="t4" dataNode="sh1,sh2" rule="mod-long" />

查看和定义分片使用

 [root@db02 conf]#vim rule.xml
 <property name="count">3</property>
     <property name="count">2</property>   #将3修改为2

准备测试环境

创建测试表

 [root@db02 conf]# 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);"
 [root@db02 conf]# 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);"

重启mycat

 [root@db02 conf]# mycat restart

测试

 [root@db01 ~]# mysql -uroot -p123456 -h 10.0.0.52 -P8066 --default-auth=mysql_native_password
 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');
 insert into t4(id,name) values(6,'x'),(8,'y'),(10,'z');

登录端节点查询数据

 [root@db02 conf]# mysql -S /data/3308/mysql.sock -e "select * from taobao.t4"
  +----+------+
 | id | name |
 +----+------+
 |  1 | a    |
 |  3 | c    |
 +----+------+
 [root@db02 conf]# mysql -S /data/3307/mysql.sock -e "select * from taobao.t4"
    +----+------+
 | id | name |
 +----+------+
 |  2 | b    |
 |  4 | d    |
 |  6 | x    |
 |  8 | y    |
 | 10 | z    |
 +----+------+

枚举分片(区域，zone)

 t5 表
 id name telnum
 1   bj   1212
 2   sh   22222
 3   bj   3333
 4   sh   44444
 5   bj   5555
 sharding-by-intfile

设计分片策略

 vim schema.xml
 添加t4之后
 <table name="t5" dataNode="sh1,sh2" rule="sharding-by-intfile" />

应用分片策略

 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>
 vim  partition-hash-int.txt 配置：
 bj=0
 sh=1
 DEFAULT_NODE=1      #默认分

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);"
重启mycat

 mycat restart

插入测试数据

 mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password
 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');

测试

 mysql -S /data/3308/mysql.sock -e "select * from taobao.t5"
 +----+------+
 | id | name |
 +----+------+
 |  2 | sh   |
 |  4 | sh   |
 |  5 | tj   |
 +----+------+
 mysql -S /data/3307/mysql.sock -e "select * from taobao.t5"
 +----+------+
 | id | name |
 +----+------+
 |  1 | bj   |
 |  3 | bj   |
 +----+------+

Mycat全局表

 a   b   c  d   .....
 join
 t
 a
 id   name   age
 1    zs     18   sh1
 id    addr  aid
 1001  bj    1
 1002  sh    2
 2    ls     19   sh2
 id    addr  aid
 1001  bj    1
 1002  sh    2
 t
 id    addr  aid
 1001  bj    1
 1002  sh    2

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。

设置全局表策略

 [root@db02 conf]#vim schema.xml
 <table name="t_area" primaryKey="id" type="global" dataNode="sh1,sh2" />

后端数据准备

[root@db02 conf]# 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);"

重启mycat

 [root@db02 conf]# mycat restart

测试

 [root@db02 conf]# mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password 

 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');
 mysql -S /data/3308/mysql.sock -e "select * from taobao.t_area"
 +----+------+
 | id | name |
 +----+------+
 |  1 | a    |
 |  2 | b    |
 |  3 | c    |
 |  4 | d    |
 +----+------+
 mysql -S /data/3307/mysql.sock -e "select * from taobao.t_area"
 +----+------+
 | id | name |
 +----+------+
 |  1 | a    |
 |  2 | b    |
 |  3 | c    |
 |  4 | d    |
 +----+------+

E-R分片(有关联的表)

 a
 join
 b
 on  a.xx =b.yy
 a
 id  name
 --------------
 1   a       sh1
 3   c
 ----------------
 2   b       sh2
 4   d
 ​
 b
 id   addr  aid
 1001  bj   1        sh1
 1002  sh   2
 ​
 1003  tj   3        sh2
 1004  wh   4

修改配置文件

 vim schema.xml
 <table name="a" dataNode="sh1,sh2" rule="mod-long_oldguo">
        <childTable name="b" joinKey="aid" parentKey="id" />
 </table>

修改分片策略

 vim rule.xml
 #mod-long之后
 <tableRule name="mod-long_oldguo">
 <rule>
 <columns>id</columns>
 <algorithm>mod-long_oldguo</algorithm>
 </rule>
 </tableRule>
 ​
 ###<property name="count">2</property>
         </function>
 添加之后
 <function name="mod-long_oldguo" class="io.mycat.route.function.PartitionByMod">               <!-- how many data nodes -->
 <property name="count">2</property>
 </function>

创建测试表

mysql -S /data/3307/mysql.sock -e "use taobao;create table a
(id int not null primary key auto_increment,name varchar(20) not null);"
 mysql -S /data/3307/mysql.sock -e "use taobao;create table b
(id int not null primary key auto_increment,addr varchar(20) not null ,aid int );"
 mysql -S /data/3308/mysql.sock -e "use taobao;create table a
(id int not null primary key auto_increment,name varchar(20) not null);"
 mysql -S /data/3308/mysql.sock -e "use taobao;create table b
 (id int not null primary key auto_increment,addr varchar(20) not null ,aid int );"

重启mycat 测试

 mycat restart
 mysql -uroot -p123456 -h10.0.0.52 -P8066 --default-auth=mysql_native_password
 use TESTDB
 insert into a(id,name) values(1,'a');
 insert into a(id,name) values(2,'b');
 insert into a(id,name) values(3,'c');
 insert into a(id,name) values(4,'d');
 insert into a(id,name) values(5,'e');
 insert into b(id,addr,aid) values(1001,'bj',1);
 insert into b(id,addr,aid) values(1002,'sj',3);
 insert into b(id,addr,aid) values(1003,'sd',4);
 insert into b(id,addr,aid) values(1004,'we',2);
 insert into b(id,addr,aid) values(1005,'er',5);

后端数据节点数据分布

 mysql -S /data/3307/mysql.sock  -e "select * from taobao.a"
 +----+------+
 | id | name |
 +----+------+
 |  2 | b    |
 |  4 | d    |
 +----+------+
 mysql -S /data/3307/mysql.sock  -e "select * from taobao.b"     +------+------+------+
 | id   | addr | aid  |
 +------+------+------+
 | 1003 | sd   |    4 |
 | 1004 | we   |    2 |
 +------+------+------+
 mysql -S /data/3308/mysql.sock  -e "select * from taobao.a"
 +----+------+
 | id | name |
 +----+------+
 |  1 | a    |
 |  3 | c    |
 |  5 | e    |
 +----+------+
 mysql -S /data/3308/mysql.sock  -e "select * from taobao.b"
 +------+------+------+
 | id   | addr | aid  |
 +------+------+------+
 | 1001 | bj   |    1 |
 | 1002 | sj   |    3 |
 | 1005 | er   |    5 |
 +------+------+------+