MYCAT divides the database and table according to the hash value of the string range

 Mainly focus on server.xml 、rule.xml、schema.xml 3 File 
 Log in logs Next wrapper.log mycat.log
wrapper.log Show MyCAT Server startup successfully Successful launch 

One ：wrapper.conf Next change java Address

wrapper.java.command=java Address 

Two ：server.xml View or change under mycat Login account password and its default library

	<user name="root" defaultAccount="true">
		<property name="password">123456</property>
		<property name="schemas">sxxfj</property>
		<property name="defaultSchema">sxxfj</property>
	</user>

Two ：schema.xml Next, change the sub database address and its sub table rules

	<schema name="sxxfj" checkSQLschema="false" sqlMaxLimit="100" randomDataNode="dn1,dn2">
		<!-- auto sharding by id (long) -->
		<!--splitTableNames  Enable <table name  Property to configure multiple tables using comma splitting , That is, multiple tables use this configuration   name  Table name  dataNode  Sub database and its address   rule  Fragmentation rule -->
		<table name="tb_order_declaration"  dataNode="dn1,dn2" rule="mod_rule" />
		<!-- <table name="oc_call" primaryKey="ID" dataNode="dn1$0-743" rule="latest-month-calldate"
			/> -->
	</schema>
	<!-- <dataNode name="dn1$0-743" dataHost="localhost1" database="db$0-743"
		/> -->
	<dataNode name="dn1" dataHost="localhost1" database="sxxfj" />
	<dataNode name="dn2" dataHost="localhost2" database="sxxfj" />
	<!--<dataNode name="dn4" dataHost="sequoiadb1" database="SAMPLE" />
	 <dataNode name="jdbc_dn1" dataHost="jdbchost" database="db1" />
	<dataNode	name="jdbc_dn2" dataHost="jdbchost" database="db2" />
	<dataNode name="jdbc_dn3" 	dataHost="jdbchost" database="db3" /> -->
	<dataHost name="localhost1" maxCon="1000" minCon="10" balance="0"
			  writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
		<heartbeat>select user()</heartbeat>
		<!-- can have multi write hosts -->
		<writeHost host="hostM1" url="mysql Address 1:3306" user="root"
				   password="mysql Address 1 password ">
		</writeHost>
		<!-- <writeHost host="hostM2" url="localhost:3316" user="root" password="123456"/> -->
	</dataHost>
	<dataHost name="localhost2" maxCon="1000" minCon="10" balance="0"
			  writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
		<heartbeat>select user()</heartbeat>
		<!-- can have multi write hosts -->
		<writeHost host="hostM2" url="mysql Address 2:3306" user="root"
				   password="mysql Address 2 password ">
		</writeHost>
		<!-- <writeHost host="hostM2" url="localhost:3316" user="root" password="123456"/> -->
	</dataHost>

3、 ... and ：rule.xml Next, change or add rules

	<tableRule name="mod_rule">
		<rule>
		  <!--  Field name  -->
			<columns>channel_no</columns>
			<!--  Fragmentation rule  -->
			<algorithm>murmur</algorithm>
		</rule>
	</tableRule>
	

	<function name="murmur"
			  class="io.mycat.route.function.PartitionByMurmurHash">
		<property name="seed">0</property><!--  The default is 0 -->
		<property name="count">2</property><!--  Number of database nodes to fragment , Must specify , Otherwise, it can't be divided  -->
		<property name="virtualBucketTimes">160</property><!--  An actual database node is mapped to so many virtual nodes , The default is 160 times , That is, the number of virtual nodes is the number of physical nodes 160 times  -->
		<!-- <property name="weightMapFile">weightMapFile</property>  Weight of nodes , Nodes without weights are 1. With properties Format of documents , From the 0 Start to count-1 That is, the node index is key, Take node weight value as value . Ownership value must be a positive integer , Otherwise, we should 1 Instead of  -->
		<!-- <property name="bucketMapPath">/etc/mycat/bucketMapPath</property>
			 Used to observe the distribution of physical nodes and virtual nodes during the test , If this property is specified , The virtual node murmur hash The mapping of values to physical nodes is output to this file by line , No default , If you don't specify , You don't export anything  -->
	</function>