MySQL高可用及读写分离笔记day17

作者: 我要笑 | 来源:发表于2019-10-15 19:35 被阅读0次

一、读写分离

1.atlas实现读写分离

大型网站为了软件大量的并发访问，除了在网站实现分布式负载均衡，远远不够。到了数据业务层、数据访问层，如果还是传统的数据结构，或者只是单单靠一台服务器扛，如此多的数据库连接操作，数据库必然会崩溃，数据丢失的话，后果更是不堪设想。这时候，我们会考虑如何减少数据库的联接，一方面采用优秀的代码框架，进行代码的优化，采用优秀的数据缓存技术，如: memcached,如果资金丰厚的话，必然会想到假设服务器群，来分担主数据库的压力。那么通过 MySQL主从配置，实现读写分离，减轻数据库压力。

基本原理让master来响应事务性操作，让slave来响应select非事务性操作，然后再采用主从复制来把
master上的事务性操作同步到slave数据库中。

[root@db03 /server/tools]# rpm -ivh Atlas-2.2.1.el6.x86_64.rpm Preparing... ################################# [100%]
Updating / installing...
1:Atlas-2.2.1-1 ################################# [100%]
[root@db03 /server/tools]# cd /usr/local/mysql-proxy/conf [root@db03 /usr/local/mysql-proxy/conf]# mv test.cnf test.cnf.bak

1.2 配置

[root@db03 /usr/local/mysql-proxy/conf]# cat > test.cnf <<EOF
 [mysql-proxy]
admin-username = user
admin-password = pwd
proxy-backend-addresses = 10.0.0.55:3306
proxy-read-only-backend-addresses = 10.0.0.52:3306,10.0.0.53:3306 
pwds =  #写 从库 repl:3yb5jEku5h4=,mha:O2jBXONX098=
daemon = true
keepalive = true
event-threads = 8
log-level = message
log-path = /usr/local/mysql-proxy/log
sql-log=ON
proxy-address = 0.0.0.0:33060
admin-address = 0.0.0.0:2345
charset=utf8
EOF
[root@db03 /usr/local/mysql-proxy/conf]# masterha_check_status -- conf=/etc/mha/app1.cnf
app1 (pid:8231) is running(0:PING_OK), master:10.0.0.51

1.3 启动atlas

[root@db03 /usr/local/mysql-proxy/conf]# /usr/local/mysql-proxy/bin/mysql- proxyd test start
error: MySQL-Proxy of test is running now
[root@db03 /usr/local/mysql-proxy/conf]# netstat -lntup|grep proxy
tcp 0 0 0.0.0.0:2345 0.0.0.0:* 8164/mysql-proxy
tcp 0 0 0.0.0.0:33060 0.0.0.0:* 8164/mysql-proxy

1.4 远程登录mha用户

[root@db03 /usr/local/mysql-proxy/conf]# mysql -umha -pmha -h 10.0.0.53 - P33060
db03 [(none)]>

1.5 检查只读id，读的操作会在2个从节点上漂移，自带负载均衡

测试读操作

db03 [(none)]>select @@server_id; +-------------+
| @@server_id |
+-------------+
| 52 |
+-------------+
1 row in set (0.01 sec)
db03 [(none)]>select @@server_id; +-------------+
| @@server_id |
+-------------+
| 53 | +-------------+
1 row in set (0.00 sec)

测试写操作

mysql> begin;select @@server_id;commit; Query OK, 0 rows affected (0.01 sec)
+-------------+
| @@server_id | +-------------+
| 51 | +-------------+
1 row in set (0.00 sec)

1.6 生产授权用户

(1)、业务主库中创建用户
例子:root@'10.0.0.%'
业务主库中

db02 [(none)]>grant all on *.* to root@'10.0.0.%' identified by '123';
Query OK, 0 rows affected, 1 warning (0.01 sec)
db02 [(none)]>

(2)将密码进行加密

cd /usr/local/mysql-proxy/bin/
[root@db03 /usr/local/mysql-proxy/bin]# ./encrypt 123 3yb5jEku5h4=

(3) 修改配置文件

vim /usr/local/mysql-proxy/conf/test.cnf

...
pwds = repl:3yb5jEku5h4=,mha:O2jBXONX098=,root:3yb5jEku5h4= ...

(4) 重启atlas

[root@db03 /usr/local/mysql-proxy/conf]# /usr/local/mysql-proxy/bin/mysql-proxyd test restart
OK: MySQL-Proxy of test is stopped
OK: MySQL-Proxy of test is started

(5)登录测试

mysql -uroot -p123 -h 10.0.0.53 -P 33060

1.7 altas基础管理

连接管理接口

[root@db03 ~]# mysql -uuser -ppwd -h10.0.0.53 -P2345

atlas常用的

(1) 查帮助

SELECT * FROM help ;

(2)查看节点信息

SELECT * FROM backends ;

(3)上线和下线节点

SET OFFLINE $backend_id ;
SET ONLINE $backend_id

(4)删除和添加节点

REMOVE BACKEND 3;
ADD SLAVE 10.0.0.53:3306;

(5) 添加用户和删除用户

SELECT * FROM pwds ; 查看

REMOVE PWD $pwd ; 删除

ADD PWD root:123;  添加 明文

ADD ENPWD $pwd 添加 密文

(6) 持久化配置

SAVE CONFIG

2.分布式数据库架构-MyCAT应用

image.png

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 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=/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

2.4 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

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 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"

2.9 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:

2.10 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;"

3. Mycat的安装

3.1 安装java环境

yum install -y java

3.2 上传到/application 并解压

略

3.3 软件介绍

conf:
schema.xml 主配置文件
rule.xml 分片策略定义文件
server.xml mycat服务有关的配置
xxxx.txt 分片参数功能有关

3.4 启动mycat

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

[root@db02 ~]# mycat start 
[root@db02 ~]# mysql -uroot -p123456 -h 10.0.0.52 -P8066

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

5. 核心配置文件使用介绍(schema.xml)

5.1 逻辑库定义

<schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="sh1"> 
</schema>

5.2 数据节点定义

        <dataNode name="sh1" dataHost="old1" database= "world" />

5.3 数据主机定义

        <dataHost name="old1" 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>

6. Mycat实现读写分离功能

[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>

重启生效:

[root@db02 /application/mycat/conf]# mycat restart

测试:
[root@db02 /application/mycat/conf]# mysql -uroot -p123456 -h 10.0.0.52 -P8066
mysql> select @@server_id;
mysql> begin; select @@server_id;commit;

7. 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="old1" database= "world" />  
    <dataHost name="old1" 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

8. 配置中的属性介绍:(了解一下)

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

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="old1" 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="old2" 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:

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))"

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

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

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 -e "use taobao;select * from t4;"
mysql -S /data/3308/mysql.sock -e "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>
</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

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 -h10.0.0.52 -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');

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/

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 -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
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');


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;"

16. E-R分片

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


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

MySQL高可用及读写分离笔记day17

一、读写分离

1.atlas实现读写分离

1.2 配置

1.3 启动atlas

1.4 远程登录mha用户

1.5 检查只读id，读的操作会在2个从节点上漂移，自带负载均衡

测试读操作

测试写操作

1.6 生产授权用户

1.7 altas基础管理

连接管理接口

atlas常用的

2.分布式数据库架构-MyCAT应用

2.1 环境准备:

2.2 2 删除历史环境:

2.3 创建相关目录初始化数据

2.4 准备配置文件和启动脚本

2.5 修改权限，启动多实例

2.6 节点主从规划

2.7 分片规划

2.8 开始配置

2.9 检测主从状态

2.10 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)

3. Mycat的安装

3.1 安装java环境

3.2 上传到/application 并解压

3.3 软件介绍

3.4 启动mycat

4. 测试数据准备

db01:

5. 核心配置文件使用介绍(schema.xml)

5.1 逻辑库定义

5.2 数据节点定义

5.3 数据主机定义

6. Mycat实现读写分离功能

7. 读写分离+高可用功能

8. 配置中的属性介绍:(了解一下)

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，

3. balance="2"，所有读操作都随机的在writeHost、readhost上分发。

1. writeType="0", 所有写操作发送到配置的第一个writeHost，

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

10. 垂直分表

11. MyCAT核心特性——分片（水平拆分）

12 .范围分片

13. 取模分片（mod-long）

14. 枚举分片

15 . Mycat全局表

16. E-R分片

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