MyCat水平分庫

一.什么是水平分庫

將一張表水平切分到多個庫中

1.1分片原則

• 1.需要分片的表是少數的
• 2.能不切分盡量不要切分
• 3.日志表可以采取歸檔方式
• 4.選擇合適的切分規則和分片建，確保數據分片均勻，否則依然存在性能瓶頸
• 5.盡量避免跨分片join操作，保證關聯操作表在同一分片

1.2分片后如何處理查詢

• 1.根據簡單分片規則，對分片鍵進行路由到正確的后端物理數據庫
• 2.如果不是使用分片鍵的話，將會遍歷后端數據庫，極大消耗性能

二.水平切分步驟

2.1根據業務狀態確定要進行水平切分的表

讀寫頻繁，訪問量非常大的表才需要切分，一般是訂單表

如何選擇分片鍵

• 1.盡可能的比較均勻分布數據到各個節點上，自增長主鍵並不是很好的選擇，因為不會用於查詢
• 2.業務字段是最頻繁的或者最重要的查詢條件

2.2分析業務模型選擇分片鍵及分片算法

一般分片鍵選擇的是頻繁作為查詢的字段，關鍵是能保證分片后的數據分布均勻，常用簡單取模算法

• 對訂單相關表進行水平切分
• 不僅僅是訂單表，經常與訂單表關聯查詢的表也需要一並分片，避免跨分片查詢，大表不適合作為全局表
• 訂單號，可以保證分片均勻，但是實際業務很少根據訂單號來查詢
• 下單人ID，業務查詢更多，更適合，但是分片並不均勻，但不嚴重，值得考慮
• 采用簡單取模分片算法，可以保證數據盡可能均勻

2.3適用mycat部署分片集群

• 1.使用schema.xml配置邏輯庫及邏輯表

<!-- <table name="order_master" primaryKey="order_id" dataNode="dn_orderdb" /> -->
	<table name="order_master" primaryKey="order_id" dataNode="dn_orderdb01,dn_orderdb02,dn_orderdb03,dn_orderdb04" rule="order_master"/>
<!-- 只需要增加表所在的物理節點schema名稱和指定規則rule -->

<dataNode name="dn_orderdb01" dataHost="mysql10143" database="orderdb01" />
<dataNode name="dn_orderdb02" dataHost="mysql10143" database="orderdb02" />
<dataNode name="dn_orderdb03" dataHost="mysql10144" database="orderdb03" />
<dataNode name="dn_orderdb04" dataHost="mysql10144" database="orderdb04" />

• 2.使用rule.xml配置分片表的分片規則

    <tableRule name="order_master">
        <rule>
            <columns>customer_id</columns>
            <algorithm>mod-long</algorithm>
        </rule>
    </tableRule>
    <function name="mod-long" class="org.opencloudb.route.function.PartitionByMod">
    <!-- 分片算法，唯一；JAVA類路徑，1.6是"io.mycat.route.function.PartitionByMod"-->
        <property name="count">4</property>
    </function>

• 3.驗證

# 現在邏輯庫上進行查看，此時是沒有數據的
# 需要提前建庫建表，否則報錯表不存在
app_imooc@172.16.10.142 00:26:  [imooc_db]> select * from order_master;
Empty set (0.08 sec)

# 在邏輯庫imooc_db上插入5條數據，正常是orderdb02 2條數據（節點索引順序為1），其他各1條數據
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70005,90005,'yzw5',5,5,5,'address1',1,20);

# truncate table報錯
app_imooc@172.16.10.142 10:51:  [imooc_db]> truncate table order_master;
ERROR 1105 (HY000): DROP command denied to user 'bm_mycat'@'172.16.10.142' for table 'order_master'

# 邏輯庫查看插入結果
app_imooc@172.16.10.142 10:50:  [imooc_db]> select order_id,order_sn,customer_id from order_master;
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|    80005 |    70002 |       90002 |
|    80005 |    70003 |       90003 |
|    80005 |    70004 |       90004 |
|    80006 |    70001 |       90001 |
|    80007 |    70005 |       90005 |
+----------+----------+-------------+
5 rows in set (0.00 sec)

# 在物理庫查看是否有這4條數據，驗證成功
root@localhost 10:52:  [orderdb01]> select order_id,order_sn,customer_id from order_master;
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|    80005 |    70004 |       90004 |
+----------+----------+-------------+
1 row in set (0.00 sec)

root@localhost 10:52:  [orderdb02]> select order_id,order_sn,customer_id from order_master;
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|    80006 |    70001 |       90001 |
|    80007 |    70005 |       90005 |
+----------+----------+-------------+
2 rows in set (0.00 sec)

root@localhost 10:05:  [orderdb03]> select order_id,order_sn,customer_id from order_master;

+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|    80005 |    70002 |       90002 |
+----------+----------+-------------+
1 row in set (0.00 sec)

root@localhost 10:52:  [orderdb04]> select order_id,order_sn,customer_id from order_master;
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|    80005 |    70003 |       90003 |
+----------+----------+-------------+
1 row in set (0.00 sec)

• 4.使用server.xml配置訪問權限

#配置用戶登錄

2.4測試分片集群，采用應用端雙寫方式進行

2.5業務及數據遷移

三.全局自增ID

• 分片表中的自增ID在邏輯表中有重復
• 第三方給ID或者使用mycat自增ID

3.1全局自增ID方法

• 1.本地文件方式：適用服務器本地磁盤的方式
• 2.數據庫方式：適用數據庫存儲的方式
• 3.本地時間戳方式：適用時間戳
• 4.分布式zookeeper生成ID

3.2本地文件全局ID

• 優點：本地加載，讀取速度快，配置簡單
• 缺點：集群部署無法使用，不同的mycat無法保證id唯一，使mycat變成了有狀態的中間件

配置方法

• 1.server.xml增加屬性

<property name="sequnceHandlerType>0</property>

• 2.sequence_conf.properties配置

#default global sequence
GLOBAL.HISIDS=
GLOBAL.MINID=10001
GLOBAL.MAXID=20000
GLOBAL.CURID=10000

# self define sequence
ORDER_MASTER.HISIDS=
ORDER_MASTER.MINID=1001
ORDER_MASTER.MAXID=2000
ORDER_MASTER.CURID=1000


# 以上配置文件中，自定義表名必須大寫書寫HISIDS：表示使用過的歷史分段(一般無特殊需要可不配置)
# MINID ：最小ID 值
# MAXID ：表示最大ID 值
# CURID ：表示當前ID 值。
# 當 sequence_conf.properties的配置名字與 表名一致的時候sql可以不包含ID字段（此處表名為id_local_file），邏輯表需要增加屬性autoIncrement="true"

• 3.插入數據

# mycat restart
# delete from order_master;
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70005,90005,'yzw5',5,5,5,'address1',1,20);
# 此時邏輯表中的order_id唯一
app_imooc@172.16.10.142 11:35:  [imooc_db]> select order_id,order_sn,customer_id from order_master;                                                                                            
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|    10004 |    70004 |       90004 |
|    10003 |    70003 |       90003 |
|    10001 |    70001 |       90001 |
|    10005 |    70005 |       90005 |
|    10002 |    70002 |       90002 |
+----------+----------+-------------+
5 rows in set (0.01 sec)

insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70005,90005,'yzw5',5,5,5,'address1',1,20);

# 此時邏輯表中的order_id依然是唯一，但是ID值使用的是自定義表自增屬性的值
app_imooc@172.16.10.142 11:48:  [imooc_db]> select order_id,order_sn,customer_id from order_master;
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|     1009 |    70003 |       90003 |
|     1008 |    70002 |       90002 |
|     1007 |    70001 |       90001 |
|     1011 |    70005 |       90005 |
|     1010 |    70004 |       90004 |
+----------+----------+-------------+
5 rows in set (0.00 sec)
# 不指定自增字段插入
# 邏輯表必須增加自增屬性，否則不指定自增字段插入則使用分片表本身自增id
#<table name="order_master" primaryKey="order_id" autoIncrement="true" dataNode="dn_orderdb01,dn_orderdb02,dn_orderdb03,dn_orderdb04" rule="order_master"/>
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70005,90005,'yzw5',5,5,5,'address1',1,20);

app_imooc@172.16.10.142 11:58:  [imooc_db]> select order_id,order_sn,customer_id from order_master;                                                                                            
+----------+----------+-------------+
| order_id | order_sn | customer_id |
+----------+----------+-------------+
|     1001 |    70001 |       90001 |
|     1005 |    70005 |       90005 |
|     1003 |    70003 |       90003 |
|     1004 |    70004 |       90004 |
|     1002 |    70002 |       90002 |
+----------+----------+-------------+
5 rows in set (0.01 sec)

3.3數據庫方式

• 優點：mycat重啟后，sequence值不會被初始化，因為從數據庫中取，每次取完按自增步長增加
• 缺點：sequence數據庫主從切換后，存在mycat適用緩存序列號，可能存在ID重復風險，可以手動增加步長避免

配置方法

• 1.server.xml增加屬性

<property name="sequnceHandlerType">1</property>

• 2.sequence_db_conf.properties

#sequence stored in datanode
GLOBAL=dn_test
ORDER_MASTER=dn_test
datanode必須要mycat能訪問的數據庫，並不一定需要在分片表的數據庫中

• 3.schema.xml增加主機節點和數據節點，讓mycat能訪問上面配置的數據節點
• 4.在對應節點的數據庫中增加函數和表，用戶必須授予表、函數、存儲過程的訪問權限

# 需要全局ID的表明需要寫入表中，大寫
INSERT INTO mycat_sequence values('ORDER_MASTER', 1, 100);
root@master 11:48:  [test]> select * from mycat_sequence;
+--------------+---------------+-----------+
| NAME         | current_value | increment |
+--------------+---------------+-----------+
| GLOBAL       |        100000 |       100 |
| ORDER_MASTER |             1 |       100 |
+--------------+---------------+-----------+
2 rows in set (0.00 sec)

• 5.schema.xml增加配置，適用全局自增IDautoIncrement="true"

<table name="order_master" primaryKey="order_id" autoIncrement="true" dataNode="dn_orderdb01,dn_orderdb02,dn_orderdb03,dn_orderdb04" rule="order_master"/>

• 6.在邏輯庫中插入數據

# 適用ID表里面的全局ID插入
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70005,90005,'yzw5',5,5,5,'address1',1,20);
# 使用ID表里面的對應表ID插入
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70005,90005,'yzw5',5,5,5,'address1',1,20);
# 不指定id列，效果同上
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70005,90005,'yzw5',5,5,5,'address1',1,20);

3.4本地時間戳方式

ID= 64 位二進制 (42(毫秒)+5(機器 ID)+5(業務編碼)+12(重復累加)

• 優點：與mycat無關，跟時間有關系
• 缺點：字段最大長度必須大於等於18，int無法滿足

配置方法

• 1.server.xml增加屬性

<property name="sequnceHandlerType">2</property>

• 2.sequence_time_conf.properties

#sequence depend on TIME
WORKID=01
DATAACENTERID=01

# 0-31任意整數

• 3.在對應節點的數據庫中增加函數和表，用戶必須授予表、函數、存儲過程的訪問權限

# 需要全局ID的表明需要寫入表中，大寫
INSERT INTO mycat_sequence values('ORDER_MASTER', 1, 100);
root@master 11:48:  [test]> select * from mycat_sequence;
+--------------+---------------+-----------+
| NAME         | current_value | increment |
+--------------+---------------+-----------+
| GLOBAL       |        100000 |       100 |
| ORDER_MASTER |             1 |       100 |
+--------------+---------------+-----------+
2 rows in set (0.00 sec)

• 5.schema.xml增加配置，適用全局自增IDautoIncrement="true"

<table name="order_master" primaryKey="order_id" autoIncrement="true" dataNode="dn_orderdb01,dn_orderdb02,dn_orderdb03,dn_orderdb04" rule="order_master"/>

• 6.在邏輯庫中插入數據

# int無法滿足
ERROR 1264 (22003): Out of range value for column 'order_id' at row 

app_imooc@172.16.10.142 12:32:  [imooc_db]> select next value for MYCATSEQ_ORDER_MASTER;
+---------------------+
| 1025962766269288448 |
+---------------------+
| 1025962766269288448 |
+---------------------+
1 row in set (0.00 sec)

app_imooc@172.16.10.142 12:32:  [imooc_db]> select next value for MYCATSEQ_GLOBAL;
+---------------------+
| 1025962827724230656 |
+---------------------+
| 1025962827724230656 |
+---------------------+
1 row in set (0.00 sec)
1
# 適用ID表里面的全局ID插入
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_GLOBAL,70005,90005,'yzw5',5,5,5,'address1',1,20);
# 使用ID表里面的對應表ID插入
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_id,order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(next value for MYCATSEQ_ORDER_MASTER,70005,90005,'yzw5',5,5,5,'address1',1,20);
# 不指定id列，效果同上
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70005,90005,'yzw5',5,5,5,'address1',1,20);

select order_id,order_sn,customer_id from order_master; 

3.5分布式zookeeper生成ID 未測試，1.5沒有默認配置文件

基於ZK 與本地配置的分布式ID 生成器(可以通過ZK 獲取集群（機房）唯一InstanceID，也可以通過配置文件配置InstanceID)ID 結構：long 64 位，ID 最大可占63 位
current time millis(微秒時間戳38 位,可以使用17 年)
instanceId（實例ID，可以通過ZK 或者配置文件獲取，5 位，也就是十進制0-31）
threadId（線程ID，9 位）
increment(自增,6 位)
一共63 位，可以承受單機房單機器單線程1000*(2^6)=640000 的並發。

• 優點：無悲觀鎖，無強競爭，吞吐量更高
• 缺點：對zookeeper集群的要求增加。

配置方法

• 1.server.xml增加屬性

<property name="sequnceHandlerType">3</property>

• 2.sequence_distributed_conf.properties

INSTANCEID=01
CLUSTERID=01

• 3.在對應節點的數據庫中增加函數和表，用戶必須授予表、函數、存儲過程的訪問權限

# 需要全局ID的表明需要寫入表中，大寫
INSERT INTO mycat_sequence values('ORDER_MASTER', 1, 100);
root@master 11:48:  [test]> select * from mycat_sequence;
+--------------+---------------+-----------+
| NAME         | current_value | increment |
+--------------+---------------+-----------+
| GLOBAL       |        100000 |       100 |
| ORDER_MASTER |             1 |       100 |
+--------------+---------------+-----------+
2 rows in set (0.00 sec)

• 5.schema.xml增加配置，適用全局自增IDautoIncrement="true"

<table name="order_master" primaryKey="order_id" autoIncrement="true" dataNode="dn_orderdb01,dn_orderdb02,dn_orderdb03,dn_orderdb04" rule="order_master"/>

• 6.在邏輯庫中插入數據

四.ER關系

• 跨分片查詢存在跨節點問題

app_imooc@172.16.10.142 13:55:  [imooc_db]> select * from order_master m join order_detail o on m.order_id=o.order_id;
ERROR 1064 (HY000): invalid route in sql, multi tables found but datanode has no intersection  sql:select * from order_master m join order_detail o on m.order_id=o.order_id

• 根據ER關系，也需要對order_detail這張表進行分片

4.1配置步驟

• 1.在原先order_master所在4個分配數據庫(orderdb01/02/03/04)中建立order_detail表結構

CREATE TABLE `order_detail` (
  `order_detail_id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增主鍵ID,訂單詳情表ID',
  `order_id` int(10) unsigned NOT NULL COMMENT '訂單表ID',
  `product_id` int(10) unsigned NOT NULL COMMENT '訂單商品ID',
  `product_name` varchar(50) NOT NULL COMMENT '商品名稱',
  `product_cnt` int(11) NOT NULL DEFAULT '1' COMMENT '購買商品數量',
  `product_price` decimal(8,2) NOT NULL COMMENT '購買商品單價',
  `average_cost` decimal(8,2) NOT NULL DEFAULT '0.00' COMMENT '平均成本價格',
  `weight` float DEFAULT NULL COMMENT '商品重量',
  `fee_money` decimal(8,2) NOT NULL DEFAULT '0.00' COMMENT '優惠分攤金額',
  `w_id` int(10) unsigned NOT NULL COMMENT '倉庫ID',
  `modified_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '最后修改時間',
  PRIMARY KEY (`order_detail_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='訂單詳情表';

• 2.schema.xml將全局分片表進行ER分片，在父表中增加子表信息

<table name="order_master" primaryKey="order_id" autoIncrement="true" dataNode="dn_orderdb01,dn_orderdb02,dn_orderdb03,dn_orderdb04" rule="order_master">
    <childTable name="order_detail" primaryKey="order_detail_id" joinKey="order_id" parentKey="order_id" autoIncrement="true" />
    <!-- 指定關聯子表的表名、主鍵，及父表關聯key、父表的主鍵，同時也需要指定全局ID -->
</table>

• 3.配置表order_detail全局自增ID(使用數據庫方式)

# server.xml

# sequence_db_conf.properties增加order_detail自增ID
#sequence stored in datanode
GLOBAL=dn_test
ORDER_MASTER=dn_test
ORDER_DETAIL=dn_test
# 數據庫中增加分片表信息
insert into mycat_sequence values('ORDER_DETAIL',1,1);

• 4.插入數據

# 先插入order_master
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70001,90001,'yzw1',1,1,1,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70002,90002,'yzw2',2,2,2,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70003,90003,'yzw3',3,3,3,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70004,90004,'yzw4',4,4,4,'address1',1,20);
insert into order_master(order_sn,customer_id,shipping_user,province,city,district,address,payment_method,order_money) values(70005,90005,'yzw5',5,5,5,'address1',1,20);
app_imooc@172.16.10.142 14:46:  [imooc_db]> select order_sn,customer_id,order_id from order_master;
+----------+-------------+----------+
| order_sn | customer_id | order_id |
+----------+-------------+----------+
|    70005 |       90005 |        5 |
|    70001 |       90001 |        6 |
|    70005 |       90005 |       10 |
|    70004 |       90004 |        4 |
|    70004 |       90004 |        9 |
|    70003 |       90003 |        3 |
|    70003 |       90003 |        8 |
|    70002 |       90002 |        2 |
|    70002 |       90002 |        7 |
+----------+-------------+----------+
9 rows in set (0.00 sec)

# 根據order_id插入order_detail
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,2,12,'商品2',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,3,13,'商品3',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,4,14,'商品4',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,5,15,'商品5',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,6,16,'商品6',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,7,17,'商品7',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,8,18,'商品8',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,9,19,'商品9',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,10,20,'商品10',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,5,21,'商品11',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,6,12,'商品2',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,8,12,'商品2',1,22.2,12,1,10,2);
insert into order_detail(order_detail_id,order_id,product_id,product_name,product_cnt,product_price,average_cost,weight,fee_money,w_id) values(next value for MYCATSEQ_ORDER_DETAIL,8,12,'商品2',1,22.2,12,1,10,2);

• 5.此時再進行分片關聯查詢驗證數據

select m.order_id,o.order_detail_id,o.product_id,o.product_name from order_master m join order_detail o on m.order_id=o.order_id;
+----------+-----------------+------------+--------------+
| order_id | order_detail_id | product_id | product_name |
+----------+-----------------+------------+--------------+
|        3 |               4 |         13 | 商品3        |
|        8 |               9 |         18 | 商品8        |
|        8 |              14 |         12 | 商品2        |
|        8 |              15 |         12 | 商品2        |
|        2 |               3 |         12 | 商品2        |
|        7 |               8 |         17 | 商品7        |
|        4 |               5 |         14 | 商品4        |
|        9 |              10 |         19 | 商品9        |
|        5 |               6 |         15 | 商品5        |
|        6 |               7 |         16 | 商品6        |
|       10 |              11 |         20 | 商品10       |
|        5 |              12 |         21 | 商品11       |
|        6 |              13 |         12 | 商品2        |
+----------+-----------------+------------+--------------+
13 rows in set (0.00 sec)

• 6.在其中一個分片上可以驗證，order_id一致的表落在同一個分片

root@localhost 15:05:  [orderdb02]> select order_sn,customer_id,order_id,mod(customer_id,4) from order_master;
+----------+-------------+----------+
| order_sn | customer_id | order_id |
+----------+-------------+----------+
|    70005 |       90005 |        5 |
|    70001 |       90001 |        6 |
|    70005 |       90005 |       10 |
+----------+-------------+----------+
3 rows in set (0.00 sec)

root@localhost 15:06:  [orderdb02]> select order_detail_id,product_id,order_id from order_detail;
+-----------------+------------+----------+
| order_detail_id | product_id | order_id |
+-----------------+------------+----------+
|               6 |         15 |        5 |
|               7 |         16 |        6 |
|              11 |         20 |       10 |
|              12 |         21 |        5 |
|              13 |         12 |        6 |
+-----------------+------------+----------+
5 rows in set (0.00 sec)