DMDS

DMDS(Distributed MySQL Database Service) is a MySQL sharding middleware base on MyCAT.

What is Different ?

• Table sharding

  Support sharding database and table in the same time.

• Simplify

  Focus on MySQL , remove some unnecessary features like zookeeper config 、 catlte .

Deploy

• Package

  After download source code, package it with maven and JDK (verison >= 7).

  mvn clean package -DskipTests=true

• Start

  Copy package dmds-server-xxx.tar to deploy directory. Run bin/startup.sh after unzip it.

  cp target/dmds-server-xxx.tar.gz deploy/
  cd deploy/
  tar -xf dmds-server-xxx.tar.gz
  cd dmds-server-1.0.0/
  ./bin/startup.sh

• Stop

  Run bin/stop.sh to stop it.

Sharding Configuration Example

Configuration files are under conf directory like MyCAT. Let's see an example for 8 sharding tables in 2 databases.

• schema.xml

  Configure hostNode、dataNode and schema. Schema name is dmds_test , data node is dn_dmds_test_00 and dn_dmds_test_01

      <schema name="dmds_test" checkSQLschema="true" sqlMaxLimit="5000" dataNode="dn_dmds_test_00">
          <table name="ts_order" primaryKey="id" dataNode="dn_dmds_test_00, dn_dmds_test_01"
                 rule="rule_dmds_test_ts_order"/>
      </schema>
      <dataNode name="dn_dmds_test_00" dataHost="dh_dmds_test_00" database="dmds_test_00"/>
      <dataNode name="dn_dmds_test_01" dataHost="dh_dmds_test_00" database="dmds_test_01"/>
      <dataHost name="dh_dmds_test_00" maxCon="100" minCon="1" balance="0" writeType="0" dbType="mysql"
                dbDriver="native" switchType="1" slaveThreshold="100">
          <heartbeat>select 1</heartbeat>
          <writeHost host="M-dh_dmds_test_00" url="localhost:3306" user="dmds_test_user" password="pwd135"/>
      </dataHost>

• rule.xml

  Configure tableRule and sharding function. Function class must be com.zhongan.dmds.route.function.PartitionTbByMod.

  • shardColumnType

    Data type of sharding column, 0 for numerical and 1 for string.

  <tableRule name="rule_dmds_test_ts_order">
      <rule>
          <columns>id</columns>
          <algorithm>function_dmds_test_ts_order</algorithm>
      </rule>
  </tableRule>
  <function name="function_dmds_test_ts_order"
            class="com.zhongan.dmds.route.function.PartitionTbByMod">
      <property name="dbCount">2</property>
      <property name="tbCount">4</property>
      <property name="shardColumnType">0</property>
  </function>

• server.xml

  Configure access user. user name is dmds_test

      <user name="dmds_test">
          <property name="password">4fe313bd</property>
          <property name="schemas">dmds_test</property>
      </user>

• Table distributed

  The physical table is distributed in order on 2 databases. Table names are automatically generated.

  select TABLE_SCHEMA, TABLE_NAME from information_schema.TABLES where TABLE_SCHEMA like 'dmds_test_%' and TABLE_NAME like 'ts_order_%';
  +--------------+---------------+
  | TABLE_SCHEMA | TABLE_NAME    |
  +--------------+---------------+
  | dmds_test_00 | ts_order_0000 |
  | dmds_test_00 | ts_order_0001 |
  | dmds_test_00 | ts_order_0002 |
  | dmds_test_00 | ts_order_0003 |
  | dmds_test_01 | ts_order_0004 |
  | dmds_test_01 | ts_order_0005 |
  | dmds_test_01 | ts_order_0006 |
  | dmds_test_01 | ts_order_0007 |
  +--------------+---------------+

Contributing

See Contributing to DMDS for details on reporting bugs and commit pull request.

License

DMDS are licensed under GPL2.0 license

More Information

For more information, please see MyCAT documents.