dbproxy分表-CFANZ编程社区

1.分表的配置

功能概述：

目前DBProxy线上使用的版本支持分表功能，分表策略目前为：hash。分表的配置可以在配置文件中进行配置，但是在0.2版本及其后的版本支持在admin端口对分表进行动态的配置。

使用方法：

配置文件中配置格式如下：

tables=dbname.tablename.shardcolname.shardnum[,dbname.tablename.shardcolname.shardnum] ##dbname:数据库名称 tablename:分表的表名 shardcolname:分表键 shardnum:分表个数 tables = person.mt.id.3

注意：

1. 如果分表的表名为：tbl ，则子表的命名应为：tbl_idx，例如 tbl_0， tbl_1 ...

2. 如果分表个数为shardnum，则子表序号从0开始到shardnum-1终止

3. 目前只支持同一个库上的分表，且每个表上只支持一个分表键

4. 目前对分表上数据的操作有一些限制，需要特别注意

例如，在数据库名：DBProxy 中创建了两个表名：shard 的子表：shard_0， shard_1，分表个数为2，规定分表键为：a，如下所示。

guest@127.0.0.1 :person03:40:18>show tables; +------------------+ \| Tables_in_person \| +------------------+ \| mt_0 \| \| mt_1 \| \| mt_2 \| +------------------+ 3 rows in set (0.00 sec)

则需要再配置文件中进行配置如下

tables = person.mt.id.3

登陆到admin 3309端进程查看

show tables; #查看系统配置的分表信息 person.mt.id.3 是否生效

[root@mycat_eye dbproxy_log]# mysql -uguest -pguest -P3309 -h127.0.0.1 Welcome to the MariaDB monitor. Commands end with ; or \g. Your MySQL connection id is 1 Server version: 5.0.99-agent-admin Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. guest@127.0.0.1 :(none)03:41:45>show tables; +--------+----------------+ \| db \| tables \| +--------+----------------+ \| person \| person.mt.id.3 \| +--------+----------------+ 1 row in set (0.00 sec)

除了在配置文件中配置分表信息之外，也可以从Admin上进行分表信息的添加和删除，其语法如下：

add tables 'dbname.tbl.shardcolname.sharnum'; #增加一列分表信息：dbname.tbl.shardcolname.sharnum

remove tables like 'dbname.tbl'; #删除一列分表信息：dbname.tbl

配置完成之后，就可以连接Proxy端口进行数据库的访问了。

注意：删除分区表时，参数是 db.name.tbl 而非完整的分表信息。

通过save config; 命令，可以将Admin端口修改的分表信息保存到配置文件中。

2.手动建表

[root@mycat_eye conf]# mysql -uguest -p -h127.0.0.1 -P3308 Enter password: Welcome to the MariaDB monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.5.35-33.0-log MySQL Community Server (GPL) Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. guest@127.0.0.1 :(none)03:05:54>show databases; +--------------------+ \| Database \| +--------------------+ \| information_schema \| \| mysql \| \| performance_schema \| \| sys \| +--------------------+ 14 rows in set (0.01 sec) guest@127.0.0.1 :(none)03:05:59>create database person; Query OK, 1 row affected (0.00 sec) guest@127.0.0.1 :(none)03:06:05>use person Database changed guest@127.0.0.1 :person03:23:10>create table mt_0( -> id int(8), -> addr varchar(20) -> ); Query OK, 0 rows affected (0.09 sec) guest@127.0.0.1 :person03:23:21>create table mt_1( -> id int(8), -> addr varchar(20) -> ); Query OK, 0 rows affected (0.04 sec) guest@127.0.0.1 :person03:23:28>create table mt_2( -> id int(8), -> addr varchar(20) -> ); Query OK, 0 rows affected (0.06 sec) guest@127.0.0.1 :person03:23:35>show tables; +------------------+ \| Tables_in_person \| +------------------+ \| mt_0 \| \| mt_1 \| \| mt_2 \| +------------------+ 4 rows in set (0.00 sec) guest@127.0.0.1 :person03:24:15>insert into mt(id,addr) values(1,'a'); Query OK, 1 row affected (0.00 sec) guest@127.0.0.1 :person03:24:29>insert into mt(id,addr) values(2,'b'); Query OK, 1 row affected (0.01 sec) guest@127.0.0.1 :person03:24:35>insert into mt(id,addr) values(3,'c'); Query OK, 1 row affected (0.01 sec) guest@127.0.0.1 :person03:24:39>insert into mt(id,addr) values(4,'c'); Query OK, 1 row affected (0.00 sec) guest@127.0.0.1 :person03:24:42>insert into mt(id,addr) values(5,'c'); Query OK, 1 row affected (0.01 sec) guest@127.0.0.1 :person03:24:45>insert into mt(id,addr) values(6,'3'); Query OK, 1 row affected (0.00 sec) guest@127.0.0.1 :person03:24:49>insert into mt(id,addr) values(7,'9'); Query OK, 1 row affected (0.00 sec) guest@127.0.0.1 :person03:24:54>insert into mt(id,addr) values(8,'u'); Query OK, 1 row affected (0.00 sec) guest@127.0.0.1 :person03:25:13>select * from mt_0; +------+------+ \| id \| addr \| +------+------+ \| 3 \| c \| \| 6 \| 3 \| +------+------+ 2 rows in set (0.00 sec) guest@127.0.0.1 :person03:25:18>select * from mt_1; +------+------+ \| id \| addr \| +------+------+ \| 1 \| a \| \| 4 \| c \| \| 7 \| 9 \| +------+------+ 3 rows in set (0.00 sec) guest@127.0.0.1 :person03:25:20>select * from mt_2; +------+------+ \| id \| addr \| +------+------+ \| 2 \| b \| \| 5 \| c \| \| 8 \| u \| +------+------+ 3 rows in set (0.00 sec)

[root@mycat_eye conf]# mysql -uguest -p -h127.0.0.1 -P3308
Enter password: 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.5.35-33.0-log MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
guest@127.0.0.1 :(none)03:05:54>show databases;
+--------------------+
| Database          |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
14 rows in set (0.01 sec)

guest@127.0.0.1 :(none)03:05:59>create database person;
Query OK, 1 row affected (0.00 sec)

guest@127.0.0.1 :(none)03:06:05>use person
Database changed


guest@127.0.0.1 :person03:23:10>create table mt_0(
    -> id int(8),
    -> addr varchar(20)
    -> );
Query OK, 0 rows affected (0.09 sec)

guest@127.0.0.1 :person03:23:21>create table mt_1(
    -> id int(8),
    -> addr varchar(20)
    -> );
Query OK, 0 rows affected (0.04 sec)

guest@127.0.0.1 :person03:23:28>create table mt_2(
    -> id int(8),
    -> addr varchar(20)
    -> );
Query OK, 0 rows affected (0.06 sec)

guest@127.0.0.1 :person03:23:35>show tables;
+------------------+
| Tables_in_person |
+------------------+
| mt_0            |
| mt_1            |
| mt_2            |
+------------------+
4 rows in set (0.00 sec)


guest@127.0.0.1 :person03:24:15>insert into mt(id,addr) values(1,'a');
Query OK, 1 row affected (0.00 sec)

guest@127.0.0.1 :person03:24:29>insert into mt(id,addr) values(2,'b');
Query OK, 1 row affected (0.01 sec)

guest@127.0.0.1 :person03:24:35>insert into mt(id,addr) values(3,'c');
Query OK, 1 row affected (0.01 sec)

guest@127.0.0.1 :person03:24:39>insert into mt(id,addr) values(4,'c');
Query OK, 1 row affected (0.00 sec)

guest@127.0.0.1 :person03:24:42>insert into mt(id,addr) values(5,'c');
Query OK, 1 row affected (0.01 sec)

guest@127.0.0.1 :person03:24:45>insert into mt(id,addr) values(6,'3');
Query OK, 1 row affected (0.00 sec)

guest@127.0.0.1 :person03:24:49>insert into mt(id,addr) values(7,'9');
Query OK, 1 row affected (0.00 sec)

guest@127.0.0.1 :person03:24:54>insert into mt(id,addr) values(8,'u');
Query OK, 1 row affected (0.00 sec)


guest@127.0.0.1 :person03:25:13>select * from mt_0;
+------+------+
| id  | addr |
+------+------+
|    3 | c    |
|    6 | 3    |
+------+------+
2 rows in set (0.00 sec)

guest@127.0.0.1 :person03:25:18>select * from mt_1;
+------+------+
| id  | addr |
+------+------+
|    1 | a    |
|    4 | c    |
|    7 | 9    |
+------+------+
3 rows in set (0.00 sec)

guest@127.0.0.1 :person03:25:20>select * from mt_2;
+------+------+
| id  | addr |
+------+------+
|    2 | b    |
|    5 | c    |
|    8 | u    |
+------+------+
3 rows in set (0.00 sec)