mycat one群：106088787。

分片規則：一致性hash

一、conf/schema.xml檔案

<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
	<schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100">
		<table name="partition_by_murmur_hash" primaryKey="id" dataNode="dn$0-2"
			   rule="partition-by-murmur-hash" />   
	</schema>
	<dataNode name="dn0" dataHost="dh-1" database="db0"/>
	<dataNode name="dn1" dataHost="dh-1" database="db1"/>
	<dataNode name="dn2" dataHost="dh-1" database="db2"/>
	<dataHost name="dh-1" maxCon="1000" minCon="10" balance="0"
			  writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
		<heartbeat>select user()</heartbeat>
		<writeHost host="hostM1" url="localhost:3306" user="root"
				   password="123456">
		</writeHost>
	</dataHost>
</mycat:schema>
 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mycat:rule SYSTEM "rule.dtd">
<mycat:rule xmlns:mycat="http://io.mycat/">
	<tableRule name="partition-by-murmur-hash">
		<rule>
			<columns>id</columns>
			<algorithm>partition-by-murmur-hash</algorithm>
		</rule>
	</tableRule>
	<function name="partition-by-murmur-hash"
		class="io.mycat.route.function.PartitionByMurmurHash">
		<property name="seed">0</property><!-- 預設是0 -->
		<property name="count">2</property><!-- 要分片的資料庫節點數量，必須指定，否則沒法分片 -->
		<property name="virtualBucketTimes">160</property><!-- 一個實際的資料庫節點被對映為這麼多虛擬節點，預設是160倍，也就是虛擬節點數是物理節點數的160倍 -->
		<!-- <property name="weightMapFile">weightMapFile</property> 節點的權重，沒有指定權重的節點預設是1。以properties檔案的格式填寫，以從0開始到count-1的整數值也就是節點索引為key，以節點權重值為值。所有權重值必須是正整數，否則以1代替 -->
		<!-- <property name="bucketMapPath">/etc/mycat/bucketMapPath</property> 
			用於測試時觀察各物理節點與虛擬節點的分佈情況，如果指定了這個屬性，會把虛擬節點的murmur hash值與物理節點的對映按行輸出到這個檔案，沒有預設值，如果不指定，就不會輸出任何東西 -->
	</function>
</mycat:rule>
 

無

四、測試用到的sql

=============按照id欄位 一致性hash ================
CREATE TABLE  partition_by_murmur_hash  (id int(10) null,`db_nm`  varchar(20) NULL);
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (1, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (2, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (3, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (4, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (5, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (6, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (7, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (8, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (9, database());
INSERT INTO `partition_by_murmur_hash` (id,db_nm) VALUES (10, database());
select * from partition_by_murmur_hash;
 

1、資料庫節點必須大於等於分片數

六、引數說明