第二十一周-day91-数据库day(13-14) 分布式架构 与 MyCAT安装和使用

三、分布式数据库架构-MyCAT

3.1 环境准备：

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

3.2 2 删除历史环境：

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

3.3 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

3.4 准备配置文件和启动脚本

========db01==============
cat >/data/3307/my.cnf</data/3308/my.cnf</data/3309/my.cnf</data/3310/my.cnf</etc/systemd/system/mysqld3307.service</etc/systemd/system/mysqld3308.service</etc/systemd/system/mysqld3309.service</etc/systemd/system/mysqld3310.service</data/3307/my.cnf</data/3308/my.cnf</data/3309/my.cnf</data/3310/my.cnf</etc/systemd/system/mysqld3307.service</etc/systemd/system/mysqld3308.service</etc/systemd/system/mysqld3309.service</etc/systemd/system/mysqld3310.service<

3.5 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
systemctl enable mysqld3307
systemctl enable mysqld3308
systemctl enable mysqld3309
systemctl enable 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'"

3.6 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

3.7 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

3.8 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 status\G"

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"

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"

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"

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 status\G"

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"

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"

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"

3.9 检测主从状态

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

3.10 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

---

4. MyCAT安装

4.1 预先安装Java运行环境

[root@db02 ~]# yum install -y java

4.2 上传到/application

[root@db02 /server/tools]# wget http://192.168.0.163/mysql/Mycat-server-1.6.5-release-20180117003034-linux.tar.gz
[root@db02 /server/tools]# tar xf Mycat-server-1.6.5-release-20180117003034-linux.tar.gz 

[root@db02 /server/tools]# ll mycat/
total 12
drwxr-xr-x 2 root root  190 Aug 21 17:10 bin
drwxrwxrwx 2 root root    6 Mar  1  2016 catlet
drwxrwxrwx 4 root root 4096 Aug 21 17:10 conf
drwxr-xr-x 2 root root 4096 Aug 21 17:10 lib
drwxrwxrwx 2 root root    6 Jan 17  2018 logs
-rwxrwxrwx 1 root root  219 Jan 17  2018 version.txt

[root@db02 /server/tools/mycat]# ll conf
autopartition-long.txt
auto-sharding-long.txt
auto-sharding-rang-mod.txt
cacheservice.properties
dbseq.sql
ehcache.xml
index_to_charset.properties
log4j2.xml
migrateTables.properties
myid.properties
partition-hash-int.txt
partition-range-mod.txt
rule.xml
schema.xml
sequence_conf.properties
sequence_db_conf.properties
sequence_distributed_conf.properties
sequence_time_conf.properties
server.xml
sharding-by-enum.txt
wrapper.conf
zkconf
zkdownload

4.3 启动和连接

移动到/application下
[root@db02 ~]# mv /server/tools/mycat /application/

配置环境变量
vim /etc/profile
export PATH=/application/mycat/bin:$PATH
source /etc/profile

启动
[root@db02 ~]# mycat start
Starting Mycat-server...

连接mycat：
mysql -uroot -p123456 -h 10.0.0.52 -P8066
mysql> 

4.4. 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

4.5. 核心配置文件使用介绍(schema.xml)

[root@db02 /application/mycat/conf]# pwd
/application/mycat/conf
[root@db02 /application/mycat/conf]# vim schema.xml

  

 
  
                 
            
                select user()  
         
                         
         
          

配置文件的介绍：

https://blog.csdn.net/qq_34457768/article/details/81625758

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。

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
 

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
select user()  监测心跳

(1) 逻辑库定义
 
  
(2) 数据节点定义
           
(3) 数据主机定义
    
                select user()  
         
                         
         
          

4.6 连接测试读写分离

[root@db02 ~]# mysql -uroot -p123456 -h 10.0.0.52 -P8066
mysql> select @@server_id;    #读
+-------------+
| @@server_id |
+-------------+
|           9 |
+-------------+
1 row in set (0.00 sec)

mysql> begin;select @@server_id;commit;   #写
Query OK, 0 rows affected (0.00 sec)

+-------------+
| @@server_id |
+-------------+
|           7 |
+-------------+
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

4.7 读写分离+高可用功能

#将原本的配置文件备份
[root@db02 /application/mycat/conf]# mv schema.xml schema.xml.bak

#添加新的配置文件(有四个节点)
[root@db02 /application/mycat/conf]# vim schema.xml
  
  

 
  
      
     
        select user()  
     
             
     
     
             
            
      

4.8 拥有了高可用的读写分离

#重启mycat
[root@db02 /application/mycat/conf]# mycat restart
Stopping Mycat-server...
Stopped Mycat-server.
Starting Mycat-server...
[root@db02 /application/mycat/conf]# mysql -uroot -p123456 -h 10.0.0.52 -P8066

# 读是三个节点轮询
mysql> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|           9 |
+-------------+
1 row in set (0.00 sec)

mysql> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|          17 |
+-------------+
1 row in set (0.00 sec)

mysql> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|           9 |
+-------------+
1 row in set (0.00 sec)


#写只有一个节点，现在节点是 7
mysql> begin;select @@server_id;commit;
Query OK, 0 rows affected (0.00 sec)

+-------------+
| @@server_id |
+-------------+
|           7 |
+-------------+
1 row in set (0.01 sec)

Query OK, 0 rows affected (0.00 sec)

4.9 检查高可用功能

节点号的切换与配置文件指定的有关，莫懵

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'"

#将db01的mysql3307数据库宕掉
[root@db01 ~]# systemctl stop mysqld3307.service 

#在db02上进mycat库读写
mysql> select @@server_id;  切换为19节点
+-------------+
| @@server_id |
+-------------+
|          19 |
+-------------+
1 row in set (0.00 sec)

mysql> begin;select @@server_id;commit;  3切换为17节点
Query OK, 0 rows affected (0.00 sec)

+-------------+
| @@server_id |
+-------------+
|          17 |
+-------------+
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

4.10 垂直分表

垂直拆分

修改mycat的配置文件：

[root@db02 ~]# cd /application/mycat/conf/
[root@db02 /application/mycat/conf]# mv  schema.xml  schema.xml.ha
[root@db02 /application/mycat/conf]# vim schema.xml




        
    
    
        select user()
    
            
    
    
            
    
    
    
        select user()
    
            
    
    
            
    
    



#重启mycat
mycat restart
 
  
 
   
 
  
 
  
4.11 创建测试库和表:（db01）
 
  
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))"

#db02上重启mycat
[root@db02 /application/mycat/conf]# mycat restart
Stopping Mycat-server...
Stopped Mycat-server.
Starting Mycat-server...
 
  
4.12 测试垂直分表
 
  
#为user表和order表 添加数据,随便添加，只是测试

[root@db02 ]# mysql -uroot -p123456 -h 10.0.0.52 -P8066
mysql> show databases;
+----------+
| DATABASE |
+----------+
| TESTDB   |
+----------+
mysql> use TESTDB
mysql> show tables;
+------------------+
| Tables_in_taobao |
+------------------+
| order_t          |
| user             |
+------------------+

mysql> insert into user(id,name) values(2,'wanglaoji');
Query OK, 1 row affected (0.02 sec)
...
mysql> select * from user;
+------+-----------+
| id   | name      |
+------+-----------+
|    1 | zs        |
|    2 | wahaha    |
|    3 | quechao   |
+------+-----------+

mysql> insert into order_t(id,name) values(99,'lcx');
Query OK, 1 row affected (0.01 sec)
...
mysql> select * from order_t;
+------+---------+
| id   | name    |
+------+---------+
|   10 | huiyuan |
|   99 | lcx     |
+------+---------+
 
  
4.13 查看
 
  
#查看3307节点的user表
[root@db01 ~]# mysql -S /data/3307/mysql.sock 
mysql> use taobao
mysql> show tables;
+------------------+
| Tables_in_taobao |
+------------------+
| user             |
+------------------+
mysql> select * from user;
+------+-----------+
| id   | name      |
+------+-----------+
|    1 | zs        |
|    1 | zs        |
|    2 | wahaha    |
|    3 | quechao   |
+------+-----------+



#查看3308节点的order表
[root@db01 ~]# mysql -S /data/3308/mysql.sock 
mysql> use taobao
mysql> show tables;
+------------------+
| Tables_in_taobao |
+------------------+
| order_t          |
+------------------+

mysql> select * from order_t;
+------+---------+
| id   | name    |
+------+---------+
|   10 | huiyuan |
|   99 | lcx     |
+------+---------+

 
  
4.14 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
 
  
4.15 范围分片
 
  
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
 
  
[root@db02 /application/mycat/conf]# cp  schema.xml schema.xml.1

vim schema.xml  #修改这一段
 
         
      

vim rule.xml

                
                        id
                        rang-long
                             

    autopartition-long.txt

 
   
 
  
4.16 准备测试环境
[root@db02 /application/mycat/conf]# cat autopartition-long.txt
0-10=0
11-20=1
4.17 创建测试表(db01)
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);"

#db02上重启mycat
mycat restart
4.18 测试(db02上)
mysql -uroot -p123456 -h10.0.0.52 -P8066
mysql> use TESTDB
Database changed
mysql> show tables;
+------------------+
| Tables_in_taobao |
+------------------+
| t3               |
| user             |
+------------------+
2 rows in set (0.00 sec)

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> select * from t3;
+----+------+
| id | name |
+----+------+
|  1 | a    |
|  2 | b    |
|  3 | c    |
|  4 | d    |
| 11 | aa   |
| 12 | bb   |
| 13 | cc   |
| 14 | dd   |
+----+------+
8 rows in set (0.13 sec)
4.19 (db01上)
 
   
分别登录后端节点查询数据效果
 
  
[root@db01 ~]# mysql -S /data/3307/mysql.sock  -e "select * from taobao.t3"
+----+------+
| id | name |
+----+------+
|  1 | a    |
|  2 | b    |
|  3 | c    |
|  4 | d    |
+----+------+
[root@db01 ~]# mysql -S /data/3308/mysql.sock  -e "select * from taobao.t3"
+----+------+
| id | name |
+----+------+
| 11 | aa   |
| 12 | bb   |
| 13 | cc   |
| 14 | dd   |
+----+------+
4.20 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
vim schema.xml

vim rule.xml
2

准备测试环境
     
创建测试表：(db01)
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);"

重启mycat (db02)
mycat restart 
 
   
 
  
4.21 测试：
#db02上添加测试数据
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');
分别登录后端节点查询数据（db01上）

[root@db01 ~]# mysql -S /data/3307/mysql.sock -e "use taobao;select * from t4"
+----+------+
| id | name |
+----+------+
|  2 | b    |
|  4 | d    |
+----+------+
[root@db01 ~]# mysql -S /data/3308/mysql.sock -e "use taobao;select * from t4"
+----+------+
| id | name |
+----+------+
|  1 | a    |
|  3 | c    |
+----+------+
4.22 14. 枚举分片
t5 表
id name telnum
1   bj   1212
2   sh   22222
3   bj   3333
4   sh   44444
5   bj   5555

sharding-by-intfile
#db02上
[root@db02 /application/mycat/conf]# vim schema.xml



[root@db02 /application/mycat/conf]# vim rule.xml
 
 name 
hash-int 
 
 

 
partition-hash-int.txt 
  1
                0
 
 
   
 
  
#partition-hash-int.txt 配置： 
[root@db02 /application/mycat/conf]# cat partition-hash-int.txt 
bj=0 
sh=1
DEFAULT_NODE=1 

按照schema.xml中的先后排序，
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
 
   
 
  
4.23 准备测试环境
db01上：
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 


添加测试数据(db02)
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');
4.24 测试效果：
 
   
分别登录后端节点查询数据
 
  
[root@db01 ~]# mysql -S /data/3307/mysql.sock -e "use taobao;select * from t5;"
+----+------+
| id | name |
+----+------+
|  1 | bj   |
|  3 | bj   |
+----+------+
[root@db01 ~]# mysql -S /data/3308/mysql.sock -e "use taobao;select * from t5;"
+----+------+
| id | name |
+----+------+
|  2 | sh   |
|  4 | sh   |
|  5 | tj   |
+----+------+
4.25 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 
4.26 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。
 
  
vim schema.xml 
 

后端数据准备(db01)
mysql -S /data/3307/mysql.sock 
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 
use taobao
create table t_area  (id int not null primary key auto_increment,name varchar(20) not null);

重启mycat (db02)
mycat restart 
4.27 准备测试环境
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');
4.28 测试效果
[root@db01 ~]# mysql -S /data/3307/mysql.sock -e "use taobao;select * from t_area;"
+----+------+
| id | name |
+----+------+
|  1 | a    |
|  2 | b    |
|  3 | c    |
|  4 | d    |
+----+------+
[root@db01 ~]# mysql -S /data/3308/mysql.sock -e "use taobao;select * from t_area;"
+----+------+
| id | name |
+----+------+
|  1 | a    |
|  2 | b    |
|  3 | c    |
|  4 | d    |
+----+------+
4.29 E-R分片
A join B  

为了防止跨分片join，可以使用E-R模式
A   join   B
on  a.xx=b.yy
join C
on A.id=C.id

#分片策略 schema.xml
 

4.30 扩展

按月的分片策略
crc32slot

---

4.31 逻辑库的操作

[root@db02 /application/mycat/conf]# vim schema.xml

[root@db02 /application/mycat/conf]# vim server.xml

mycat restart
mysql -uroot -p123456 -h10.0.0.52 -P8066
mysql> show databases;
+----------+
| DATABASE |
+----------+
| oldguo   |
+----------+