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new 5966eec936c Add DistSQL manual mode whole process example (#16878)
5966eec936c is described below
commit 5966eec936cd619b7c8d926e0a2807480c64ac41
Author: Hongsheng Zhong <[email protected]>
AuthorDate: Sat Apr 16 22:26:30 2022 +0800
Add DistSQL manual mode whole process example (#16878)
* Add DistSQL manual mode whole process example
* Update SQL keyword to uppercase
---
.../user-manual/shardingsphere-scaling/usage.cn.md | 265 +++++++++++++++++++--
.../user-manual/shardingsphere-scaling/usage.en.md | 264 ++++++++++++++++++--
2 files changed, 481 insertions(+), 48 deletions(-)
diff --git
a/docs/document/content/user-manual/shardingsphere-scaling/usage.cn.md
b/docs/document/content/user-manual/shardingsphere-scaling/usage.cn.md
index e03d0b8ec5b..bc31d207c99 100644
--- a/docs/document/content/user-manual/shardingsphere-scaling/usage.cn.md
+++ b/docs/document/content/user-manual/shardingsphere-scaling/usage.cn.md
@@ -108,21 +108,19 @@ max_replication_slots = 10
示例：
```sql
-preview select count(1) from t_order;
+preview SELECT COUNT(1) FROM t_order;
```
返回信息：
```
-mysql> preview select count(1) from t_order;
-+------------------+--------------------------------+
-| data_source_name | sql |
-+------------------+--------------------------------+
-| ds_0 | select count(1) from t_order_0 |
-| ds_0 | select count(1) from t_order_1 |
-| ds_1 | select count(1) from t_order_0 |
-| ds_1 | select count(1) from t_order_1 |
-+------------------+--------------------------------+
-4 rows in set (0.00 sec)
+mysql> preview SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_0 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_1 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+2 rows in set (0.65 sec)
```
#### 创建迁移任务
@@ -264,23 +262,20 @@ mysql> show scaling status 660152090995195904;
示例：
```sql
-preview select count(1) from t_order;
+preview SELECT COUNT(1) FROM t_order;
```
返回信息：
```
-mysql> preview select count(1) from t_order;
-+------------------+--------------------------------+
-| data_source_name | sql |
-+------------------+--------------------------------+
-| ds_2 | select count(1) from t_order_0 |
-| ds_2 | select count(1) from t_order_1 |
-| ds_3 | select count(1) from t_order_0 |
-| ds_3 | select count(1) from t_order_1 |
-| ds_4 | select count(1) from t_order_0 |
-| ds_4 | select count(1) from t_order_1 |
-+------------------+--------------------------------+
-6 rows in set (0.01 sec)
+mysql> preview SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_2 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_3 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_4 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+3 rows in set (0.21 sec)
```
#### 其他 DistSQL
@@ -289,3 +284,225 @@ mysql> preview select count(1) from t_order;
### DistSQL 手动模式接口
数据校验、切换配置等操作可以手动执行。详情请参见：[RAL
#弹性伸缩](/cn/user-manual/shardingsphere-proxy/distsql/syntax/ral/#%E5%BC%B9%E6%80%A7%E4%BC%B8%E7%BC%A9)。
+
+### DistSQL 手动模式完整流程示例
+
+本示例演示从已有 MySQL 数据库迁移到 proxy。
+
+除了明确说明在 MySQL 执行的 SQL，其他都是在 proxy 执行。
+
+#### 新建源端库
+
+已有数据不需要这个步骤。这里是模拟一个源端库用于测试。
+
+在 MySQL 执行 SQL：
+```sql
+DROP DATABASE IF EXISTS scaling_ds_0;
+CREATE DATABASE scaling_ds_0 DEFAULT CHARSET utf8;
+
+DROP DATABASE IF EXISTS scaling_ds_1;
+CREATE DATABASE scaling_ds_1 DEFAULT CHARSET utf8;
+```
+
+#### 登录 proxy
+
+```shell
+mysql -h127.0.0.1 -P3307 -uroot -proot
+```
+
+#### 创建并配置 schema
+
+创建 schema：
+```sql
+CREATE DATABASE scaling_db;
+
+USE scaling_db
+```
+
+加入源端数据库资源：
+```sql
+ADD RESOURCE ds_0 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_0?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+), ds_1 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_1?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+);
+```
+
+配置规则：
+把现有系统中的表配置到规则里，使用 tables 规则 INLINE 算法，方便适配已有的表名。
+```sql
+CREATE SHARDING ALGORITHM database_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="ds_${user_id % 2}"))
+);
+CREATE SHARDING ALGORITHM t_order_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="t_order_${order_id % 2}"))
+);
+CREATE SHARDING ALGORITHM t_order_item_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="t_order_item_${order_id %
2}"))
+);
+
+CREATE SHARDING TABLE RULE t_order (
+DATANODES("ds_${0..1}.t_order_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_id,TYPE(NAME=snowflake))
+), t_order_item (
+DATANODES("ds_${0..1}.t_order_item_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_item_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_item_id,TYPE(NAME=snowflake))
+);
+
+CREATE SHARDING BINDING TABLE RULES (t_order,t_order_item);
+
+CREATE SHARDING SCALING RULE scaling_manual2 (
+DATA_CONSISTENCY_CHECKER(TYPE(NAME=CRC32_MATCH))
+);
+```
+
+#### 创建测试表并初始化数据
+
+该步骤在实际使用中不需要。
+
+```sql
+CREATE TABLE t_order (order_id INT NOT NULL, user_id INT NOT NULL, status
VARCHAR(45) CHARSET utf8mb4, PRIMARY KEY (order_id));
+CREATE TABLE t_order_item (item_id INT NOT NULL, order_id INT NOT NULL,
user_id INT NOT NULL, status VARCHAR(45) CHARSET utf8mb4, creation_date DATE,
PRIMARY KEY (item_id));
+
+INSERT INTO t_order (order_id, user_id, status) VALUES
(1,2,'ok'),(2,4,'ok'),(3,6,'ok'),(4,1,'ok'),(5,3,'ok'),(6,5,'ok');
+INSERT INTO t_order_item (item_id, order_id, user_id, status) VALUES
(1,1,2,'ok'),(2,2,4,'ok'),(3,3,6,'ok'),(4,4,1,'ok'),(5,5,3,'ok'),(6,6,5,'ok');
+```
+
+#### 执行迁移
+
+预览分片：
+```sql
+mysql> PREVIEW SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_0 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_1 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+2 rows in set (0.65 sec)
+```
+
+在 MySQL 创建目标端库：
+```sql
+DROP DATABASE IF EXISTS scaling_ds_10;
+CREATE DATABASE scaling_ds_10 DEFAULT CHARSET utf8;
+
+DROP DATABASE IF EXISTS scaling_ds_11;
+CREATE DATABASE scaling_ds_11 DEFAULT CHARSET utf8;
+
+DROP DATABASE IF EXISTS scaling_ds_12;
+CREATE DATABASE scaling_ds_12 DEFAULT CHARSET utf8;
+```
+
+加入目标端数据库资源：
+```sql
+ADD RESOURCE ds_2 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_10?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+), ds_3 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_11?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+), ds_4 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_12?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+);
+```
+
+修改分片规则触发迁移：
+```sql
+ALTER SHARDING ALGORITHM database_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="ds_${user_id % 3 + 2}"))
+);
+
+ALTER SHARDING TABLE RULE t_order (
+DATANODES("ds_${2..4}.t_order_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_id,TYPE(NAME=snowflake))
+), t_order_item (
+DATANODES("ds_${2..4}.t_order_item_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_item_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_item_id,TYPE(NAME=snowflake))
+);
+```
+
+查看当前迁移任务的进度：
+```sql
+mysql> SHOW SCALING LIST;
++--------------------------------------------+----------------------+----------------------+--------+---------------------+-----------+
+| id | tables |
sharding_total_count | active | create_time | stop_time |
++--------------------------------------------+----------------------+----------------------+--------+---------------------+-----------+
+| 0130317c30317c3054317c7363616c696e675f6462 | t_order,t_order_item | 2
| true | 2022-04-16 17:22:19 | NULL |
++--------------------------------------------+----------------------+----------------------+--------+---------------------+-----------+
+1 row in set (0.34 sec)
+
+mysql> SHOW SCALING STATUS 0130317c30317c3054317c7363616c696e675f6462;
++------+-------------+--------------------------+--------+-------------------------------+--------------------------+
+| item | data_source | status | active |
inventory_finished_percentage | incremental_idle_seconds |
++------+-------------+--------------------------+--------+-------------------------------+--------------------------+
+| 0 | ds_0 | EXECUTE_INCREMENTAL_TASK | true | 100
| 8 |
+| 1 | ds_1 | EXECUTE_INCREMENTAL_TASK | true | 100
| 7 |
++------+-------------+--------------------------+--------+-------------------------------+--------------------------+
+2 rows in set (0.02 sec)
+```
+当 status 达到 EXECUTE_INCREMENTAL_TASK，全量迁移已完成，在增量迁移阶段。
+
+
+选择一个业务低峰期，对源端库或数据操作入口做停写。
+
+proxy 停写：
+```sql
+mysql> STOP SCALING SOURCE WRITING 0130317c30317c3054317c7363616c696e675f6462;
+Query OK, 0 rows affected (0.07 sec)
+```
+
+数据一致性校验：
+```sql
+mysql> CHECK SCALING 0130317c30317c3054317c7363616c696e675f6462 BY TYPE
(NAME=CRC32_MATCH);
++--------------+----------------------+----------------------+-----------------------+-------------------------+
+| table_name | source_records_count | target_records_count |
records_count_matched | records_content_matched |
++--------------+----------------------+----------------------+-----------------------+-------------------------+
+| t_order | 6 | 6 | true
| true |
+| t_order_item | 6 | 6 | true
| true |
++--------------+----------------------+----------------------+-----------------------+-------------------------+
+2 rows in set (2.16 sec)
+```
+
+切换元数据：
+```sql
+mysql> APPLY SCALING 0130317c30317c3054317c7363616c696e675f6462;
+Query OK, 0 rows affected (0.22 sec)
+```
+
+预览分片是否已生效：
+```sql
+mysql> PREVIEW SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_2 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_3 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_4 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+3 rows in set (0.21 sec)
+```
+数据已经分片到新的数据库资源。
+
+可选择性删除不再使用的 ds_0 和 ds_1。
diff --git
a/docs/document/content/user-manual/shardingsphere-scaling/usage.en.md
b/docs/document/content/user-manual/shardingsphere-scaling/usage.en.md
index 5b125e09487..feb974a4ef8 100644
--- a/docs/document/content/user-manual/shardingsphere-scaling/usage.en.md
+++ b/docs/document/content/user-manual/shardingsphere-scaling/usage.en.md
@@ -110,21 +110,19 @@ Please refer to [Write Ahead
Log](https://www.postgresql.org/docs/9.6/runtime-co
Example:
```sql
-preview select count(1) from t_order;
+preview SELECT COUNT(1) FROM t_order;
```
Response:
```
-mysql> preview select count(1) from t_order;
-+------------------+--------------------------------+
-| data_source_name | sql |
-+------------------+--------------------------------+
-| ds_0 | select count(1) from t_order_0 |
-| ds_0 | select count(1) from t_order_1 |
-| ds_1 | select count(1) from t_order_0 |
-| ds_1 | select count(1) from t_order_1 |
-+------------------+--------------------------------+
-4 rows in set (0.00 sec)
+mysql> preview SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_0 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_1 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+2 rows in set (0.65 sec)
```
#### Start scaling job
@@ -266,23 +264,20 @@ If `status` fails, you can check the log of `proxy` to
view the error stack and
Example:
```sql
-preview select count(1) from t_order;
+preview SELECT COUNT(1) FROM t_order;
```
Response:
```
-mysql> preview select count(1) from t_order;
-+------------------+--------------------------------+
-| data_source_name | sql |
-+------------------+--------------------------------+
-| ds_2 | select count(1) from t_order_0 |
-| ds_2 | select count(1) from t_order_1 |
-| ds_3 | select count(1) from t_order_0 |
-| ds_3 | select count(1) from t_order_1 |
-| ds_4 | select count(1) from t_order_0 |
-| ds_4 | select count(1) from t_order_1 |
-+------------------+--------------------------------+
-6 rows in set (0.01 sec)
+mysql> PREVIEW SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_2 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_3 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_4 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+3 rows in set (0.21 sec)
```
#### Other DistSQL
@@ -291,3 +286,224 @@ Please refer to
[RAL#Scaling](/en/user-manual/shardingsphere-proxy/distsql/synta
### DistSQL API for manual mode
Data consistency check and switch configuration could be emitted manually.
Please refer to
[RAL#Scaling](/en/user-manual/shardingsphere-proxy/distsql/syntax/ral/#scaling)
for more details.
+
+### DistSQL manual mode whole process example
+
+This example show how to migrate data from MySQL to proxy.
+
+Most SQLs should be executed in proxy, except few ones mentioned for MySQL.
+
+#### Create source databases
+
+It's not needed in practice. It just simulates databases for testing.
+
+Execute SQLs in MySQL:
+```sql
+DROP DATABASE IF EXISTS scaling_ds_0;
+CREATE DATABASE scaling_ds_0 DEFAULT CHARSET utf8;
+
+DROP DATABASE IF EXISTS scaling_ds_1;
+CREATE DATABASE scaling_ds_1 DEFAULT CHARSET utf8;
+```
+
+#### Login proxy
+
+```shell
+mysql -h127.0.0.1 -P3307 -uroot -proot
+```
+
+#### Create and configure schema
+
+Create schema:
+```sql
+CREATE DATABASE scaling_db;
+
+USE scaling_db
+```
+
+Add source database resource:
+```sql
+ADD RESOURCE ds_0 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_0?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+), ds_1 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_1?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+);
+```
+
+Configure rules:
+Configure tables of existing system in sharding rule, sharding table rules and
INLINE algorithm will be used to fit existing tables name.
+```sql
+CREATE SHARDING ALGORITHM database_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="ds_${user_id % 2}"))
+);
+CREATE SHARDING ALGORITHM t_order_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="t_order_${order_id % 2}"))
+);
+CREATE SHARDING ALGORITHM t_order_item_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="t_order_item_${order_id %
2}"))
+);
+
+CREATE SHARDING TABLE RULE t_order (
+DATANODES("ds_${0..1}.t_order_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_id,TYPE(NAME=snowflake))
+), t_order_item (
+DATANODES("ds_${0..1}.t_order_item_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_item_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_item_id,TYPE(NAME=snowflake))
+);
+
+CREATE SHARDING BINDING TABLE RULES (t_order,t_order_item);
+
+CREATE SHARDING SCALING RULE scaling_manual2 (
+DATA_CONSISTENCY_CHECKER(TYPE(NAME=CRC32_MATCH))
+);
+```
+
+#### Create test tables and initialize records
+
+It's not needed in practice.
+
+```sql
+CREATE TABLE t_order (order_id INT NOT NULL, user_id INT NOT NULL, status
VARCHAR(45) CHARSET utf8mb4, PRIMARY KEY (order_id));
+CREATE TABLE t_order_item (item_id INT NOT NULL, order_id INT NOT NULL,
user_id INT NOT NULL, status VARCHAR(45) CHARSET utf8mb4, creation_date DATE,
PRIMARY KEY (item_id));
+
+INSERT INTO T_ORDER (order_id, user_id, status) VALUES
(1,2,'ok'),(2,4,'ok'),(3,6,'ok'),(4,1,'ok'),(5,3,'ok'),(6,5,'ok');
+INSERT INTO T_ORDER_ITEM (item_id, order_id, user_id, status) VALUES
(1,1,2,'ok'),(2,2,4,'ok'),(3,3,6,'ok'),(4,4,1,'ok'),(5,5,3,'ok'),(6,6,5,'ok');
+```
+
+#### Run migration
+
+Preview sharding:
+```sql
+mysql> PREVIEW SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_0 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_1 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+2 rows in set (0.65 sec)
+```
+
+Create target databases in MySQL:
+```sql
+DROP DATABASE IF EXISTS scaling_ds_10;
+CREATE DATABASE scaling_ds_10 DEFAULT CHARSET utf8;
+
+DROP DATABASE IF EXISTS scaling_ds_11;
+CREATE DATABASE scaling_ds_11 DEFAULT CHARSET utf8;
+
+DROP DATABASE IF EXISTS scaling_ds_12;
+CREATE DATABASE scaling_ds_12 DEFAULT CHARSET utf8;
+```
+
+Add target database resource:
+```sql
+ADD RESOURCE ds_2 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_10?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+), ds_3 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_11?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+), ds_4 (
+
URL="jdbc:mysql://127.0.0.1:3306/scaling_ds_12?serverTimezone=UTC&useSSL=false",
+ USER=root,
+ PASSWORD=root,
+ PROPERTIES("maximumPoolSize"=50,"idleTimeout"="60000")
+);
+```
+
+Alter sharding rule to emit scaling job:
+```sql
+ALTER SHARDING ALGORITHM database_inline (
+TYPE(NAME=INLINE,PROPERTIES("algorithm-expression"="ds_${user_id % 3 + 2}"))
+);
+
+ALTER SHARDING TABLE RULE t_order (
+DATANODES("ds_${2..4}.t_order_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_id,TYPE(NAME=snowflake))
+), t_order_item (
+DATANODES("ds_${2..4}.t_order_item_${0..1}"),
+DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
+TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=t_order_item_inline),
+KEY_GENERATE_STRATEGY(COLUMN=order_item_id,TYPE(NAME=snowflake))
+);
+```
+
+Query job progress:
+```sql
+mysql> SHOW SCALING LIST;
++--------------------------------------------+----------------------+----------------------+--------+---------------------+-----------+
+| id | tables |
sharding_total_count | active | create_time | stop_time |
++--------------------------------------------+----------------------+----------------------+--------+---------------------+-----------+
+| 0130317c30317c3054317c7363616c696e675f6462 | t_order,t_order_item | 2
| true | 2022-04-16 17:22:19 | NULL |
++--------------------------------------------+----------------------+----------------------+--------+---------------------+-----------+
+1 row in set (0.34 sec)
+
+mysql> SHOW SCALING STATUS 0130317c30317c3054317c7363616c696e675f6462;
++------+-------------+--------------------------+--------+-------------------------------+--------------------------+
+| item | data_source | status | active |
inventory_finished_percentage | incremental_idle_seconds |
++------+-------------+--------------------------+--------+-------------------------------+--------------------------+
+| 0 | ds_0 | EXECUTE_INCREMENTAL_TASK | true | 100
| 8 |
+| 1 | ds_1 | EXECUTE_INCREMENTAL_TASK | true | 100
| 7 |
++------+-------------+--------------------------+--------+-------------------------------+--------------------------+
+2 rows in set (0.02 sec)
+```
+When `status` is `EXECUTE_INCREMENTAL_TASK`, it means inventory migration
stage is successful, it's running on incremental migration stage.
+
+Choose an idle time of business system, stop source database writing or stop
upper database operation.
+
+Stop source writing in proxy:
+```sql
+mysql> STOP SCALING SOURCE WRITING 0130317c30317c3054317c7363616c696e675f6462;
+Query OK, 0 rows affected (0.07 sec)
+```
+
+Data consistency check:
+```sql
+mysql> CHECK SCALING 0130317c30317c3054317c7363616c696e675f6462 BY TYPE
(NAME=CRC32_MATCH);
++--------------+----------------------+----------------------+-----------------------+-------------------------+
+| table_name | source_records_count | target_records_count |
records_count_matched | records_content_matched |
++--------------+----------------------+----------------------+-----------------------+-------------------------+
+| t_order | 6 | 6 | true
| true |
+| t_order_item | 6 | 6 | true
| true |
++--------------+----------------------+----------------------+-----------------------+-------------------------+
+2 rows in set (2.16 sec)
+```
+
+Apply metadata:
+```sql
+mysql> APPLY SCALING 0130317c30317c3054317c7363616c696e675f6462;
+Query OK, 0 rows affected (0.22 sec)
+```
+
+Preview sharding again:
+```sql
+mysql> PREVIEW SELECT COUNT(1) FROM t_order;
++------------------+-------------------------------------------------------------------------+
+| data_source_name | actual_sql
|
++------------------+-------------------------------------------------------------------------+
+| ds_2 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_3 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
+| ds_4 | SELECT COUNT(1) FROM t_order_0 UNION ALL SELECT COUNT(1)
FROM t_order_1 |
++------------------+-------------------------------------------------------------------------+
+3 rows in set (0.21 sec)
+```
+Sharding already take effect.
+
+Optionally, unused `ds_0` and `ds_1` could be removed.
