Score
0
Watch 41 Star 111 Fork 14

Jasen / cetusCGPL-2.0

Join us
Explore and code with more than 2 million developers,Free private repositories !:)
Sign up
Cetus是由C语言开发的关系型数据库MySQL的中间件,主要提供了一个全面的数据库访问代理功能。Cetus连接方式与MySQL基本兼容,应用程序几乎不用修改即可通过Cetus访问数据库,实现了数据库层的水平扩展和高可用。 spread retract

  • C 59.7%
  • Perl 11.4%
  • Shell 10.1%
  • Roff 7.7%
  • Python 5.1%
  • Other 6.0%
Clone or download
cetus-partition-profile.md 3.88 KB
Copy Edit Web IDE Raw Blame History
tsthght authored 2019-04-12 12:10 . Update cetus-partition-profile.md

分表(partition)版配置文件说明

1 分表版本编译方法

分表版本编译方法和分片(shard)版本是一样的,例如:

CFLAGS='-g -Wpointer-to-int-cast' cmake ../ -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=/home/user/cetus_install -DSIMPLE_PARSER=OFF

详细的编译方法,详见Cetus 安装说明

2 分表版本配置方法

分表(partition)版配置文件基本跟分片(shard)版本一样,不同之处在shard.conf文件:

  • 配置partition-mode=true, 使cetus工作在分表模式
  • proxy-backend-addresses和proxy-read-only-backend-addresses配置具体参考读写分离,不需要像分库那样加group

3 分表版本的约定

  • 子表名的约定

自表名的命名规则是:原表名_vdb分表名。

例如,配置文件sharding.json中配置如下:

"vdb": [
    {
      "id": 1,
      "type": "int",
      "method": "hash",
      "num": 4,
      "partitions": {"data1": [0,1], "data2": [2,3]}
    }],
"table": [   
    {"vdb": 1, "db": "ght", "table": "t1", "pkey": "id"}
    ]
} 

则表t1分2个子表,分表之后的各个子表名为:t1_data1, t1_data2。

  • 子表的创建

目前Cetus不负责子表的创建。需要用户在Cetus中配置好分表规则后,自己手动在主库上创建各个子表。

4 举例

假设,目前需要将表tb,按照hash方式分成4个子表,每个子表表名分别为:tb_hs0, tb_hs1, tb_hs2, tb_hs3。则实现上述需求,配置步骤如下:

  • 编译shard版本的Cetus,参考编译命令如下:
CFLAGS='-g -Wpointer-to-int-cast' cmake ../ -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=/home/user/cetus_install -DSIMPLE_PARSER=OFF
  • 配置shard.conf文件,使Cetus工作在分表模式下。参考配置如下:
proxy-backend-addresses=172.17.0.3:3306
proxy-read-only-backend-addresses=172.17.0.4:3306
partition-mode=true

特别注意, 不需要在IP PORT后添加@data1

  • 配置sharding.json,配置分表规则
{
  "vdb": [
    {
      "id": 1,
      "type": "int",
      "method": "hash",
      "num": 8,
      "partitions": {"hs0": [0,1], "hs1": [2,3], "hs2": [4,5], "hs3": [6,7]}
    }
  ],
 "table": [
    {"vdb": 1, "db": "ght", "table": "tb", "pkey": "id"}
  ]
}
  • 创建子表

直连主库,创建对应的子表:

use ght;
create table tb_hs0 (id int);
create table tb_hs1 (id int);
create table tb_hs2 (id int);
create table tb_hs3 (id int);
  • 启动Cetus
./bin/cetus --defaults-file=conf/shard.conf
  • 验证

登录Cetus的代理端口,执行shard_explain命令,查看路由情况:

shard_explain select * from tb where id = 7;
+--------+-------------------------------------+
| groups | sql                                 |
+--------+-------------------------------------+
| hs3    | SELECT * FROM tb_hs3  WHERE id = 7; |
+--------+-------------------------------------+
1 row in set (0.00 sec)

shard_explain select * from tb where id = 5;
+--------+-------------------------------------+
| groups | sql                                 |
+--------+-------------------------------------+
| hs2    | SELECT * FROM tb_hs2  WHERE id = 5; |
+--------+-------------------------------------+
1 row in set (0.00 sec)

shard_explain select * from tb where id = 3;
+--------+-------------------------------------+
| groups | sql                                 |
+--------+-------------------------------------+
| hs1    | SELECT * FROM tb_hs1  WHERE id = 3; |
+--------+-------------------------------------+
1 row in set (0.00 sec)

shard_explain select * from tb where id = 1;
+--------+-------------------------------------+
| groups | sql                                 |
+--------+-------------------------------------+
| hs0    | SELECT * FROM tb_hs0  WHERE id = 1; |
+--------+-------------------------------------+
1 row in set (0.00 sec)

Comment ( 0 )

Sign in for post a comment

C
1
https://gitee.com/gitcrazy/cetus.git
git@gitee.com:gitcrazy/cetus.git
gitcrazy
cetus
cetus
master

Help Search