mysql分布式架构mycat

Posted 叶落kiss

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1. 转自https://www.jianshu.com/p/5e0062f6cf62

1. MyCAT基础架构图

 
技术图片
image.png

2. MyCAT基础架构准备

2.1 环境准备:

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

2.2 删除历史环境:

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

2.3 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=/app/mysql
mysqld --initialize-insecure  --user=mysql --datadir=/data/3308/data --basedir=/app/mysql
mysqld --initialize-insecure  --user=mysql --datadir=/data/3309/data --basedir=/app/mysql
mysqld --initialize-insecure  --user=mysql --datadir=/data/3310/data --basedir=/app/mysql

2.4 准备配置文件和启动脚本

========db01==============
cat >/data/3307/my.cnf<<EOF
[mysqld]
basedir=/app/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=/app/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=/app/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=/app/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=/app/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=/app/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=/app/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=/app/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf
LimitNOFILE = 5000
EOF
========db02===============
cat >/data/3307/my.cnf<<EOF
[mysqld]
basedir=/app/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=/app/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=/app/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=/app/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=/app/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=/app/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=/app/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=/app/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf
LimitNOFILE = 5000
EOF

2.5 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‘"

2.6 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

2.7 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

2.8 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"

2.9 检测主从状态

mysql -S /data/3307/mysql.sock -e "show slave statusG"|grep Yes
mysql -S /data/3308/mysql.sock -e "show slave statusG"|grep Yes
mysql -S /data/3309/mysql.sock -e "show slave statusG"|grep Yes
mysql -S /data/3310/mysql.sock -e "show slave statusG"|grep Yes
注:如果中间出现错误,在每个节点进行执行以下命令
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;"

2.10 MySQL分布式架构介绍

 
技术图片
image.png
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

2.11 企业代表产品

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

3. MyCAT安装

3.1 预先安装Java运行环境

yum install -y java

3.2下载

Mycat-server-xxxxx.linux.tar.gz
http://dl.mycat.io/

3.3 解压文件

tar xf Mycat-server-1.6.5-release-20180122220033-linux.tar.gz

3.4 软件目录结构

ls
bin  catlet  conf  lib  logs  version.txt

3.5 启动和连接

配置环境变量
vim /etc/profile
export PATH=/application/mycat/bin:$PATH
source /etc/profile
启动
mycat start
连接mycat:
mysql -uroot -p123456 -h 127.0.0.1 -P8066

4. 配置文件介绍

logs目录:
wrapper.log       ---->mycat启动日志
mycat.log         ---->mycat详细工作日志
conf目录:
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

5.应用前环境准备

5.1 用户创建及数据库导入

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

5.2 配置文件处理

cd /application/mycat/conf
mv schema.xml schema.xml.bak
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= "wordpress" />  
    <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>

6. 配置文件简单介绍

6.1 逻辑库:schema

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

6.2 数据节点:datanode

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

6.3 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>  

7. 读写分离结构配置

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> 
        </dataHost>  
</mycat:schema>

重启mycat
mycat restart

读写分离测试
 mysql -uroot -p -h 127.0.0.1 -P8066
 show variables like ‘server_id‘;
 begin;
 show variables like ‘server_id‘;

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。

8. 配置读写分离及高可用

[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
 

9. 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",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

10. 垂直分表

 
技术图片
image.png

 
技术图片
image.png
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>

创建测试库和表:
[root@db01 conf]# mysql -S /data/3307/mysql.sock -e "create database taobao charset utf8;"
[root@db01 conf]# mysql -S /data/3308/mysql.sock -e "create database taobao charset utf8;"
[root@db01 conf]# mysql -S /data/3307/mysql.sock -e "use taobao;create table user(id int,name varchar(20))";
[root@db01 conf]# mysql -S /data/3308/mysql.sock -e "use taobao;create table order_t(id int,name varchar(20))"

11. 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

12 .范围分片

 
技术图片
image.png
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
mv 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

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);"

测试:
重启mycat
mycat restart
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‘);

13. 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
<table name="t4" dataNode="sh1,sh2" rule="mod-long" />
vim rule.xml
<property name="count">2</property>

准备测试环境
     
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);"

重启mycat 
mycat restart 

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‘);

分别登录后端节点查询数据
mysql -S /data/3307/mysql.sock 
use taobao
select * from t4;

mysql -S /data/3308/mysql.sock 
use taobao
select * from t4;

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
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>  # 该配置项用于让枚举识别中文字符串值
                <property name="defaultNode">0</property>
</function> 

partition-hash-int.txt 配置: 
bj=0 
sh=1
DEFAULT_NODE=1   # 用于设定枚举值之外的数据存储节点
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

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 
mysql -uroot -p123456 -h10.0.0.51 -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‘);

15 . 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。 

vim schema.xml 
<table name="t_area" primaryKey="id"  type="global" dataNode="sh1,sh2" /> 

后端数据准备
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 
mycat restart 

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‘);

16. 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
<table name="A" dataNode="sh1,sh2" rule="mod-long"> 
       <childTable name="B" joinKey="yy" parentKey="xx" /> 
</table> 
 
 
 

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