Storage Unit Definition

Syntax

  1. REGISTER STORAGE UNIT storageUnitDefinition [, storageUnitDefinition] ...
  3. ALTER STORAGE UNIT storageUnitDefinition [, storageUnitDefinition] ...
  5. UNREGISTER STORAGE UNIT storageUnitName [, storageUnitName] ... [ignore single tables]
  7. storageUnitDefinition:
  8.     simpleSource | urlSource
  10. simpleSource:
  11.     storageUnitName(HOST=hostname,PORT=port,DB=dbName,USER=user [,PASSWORD=password] [,PROPERTIES(property [,property]) ...])
  13. urlSource:
  14.     storageUnitName(URL=url,USER=user [,PASSWORD=password] [,PROPERTIES(property [,property]) ...])
  16. property:
  17.     key=value

Parameters Explained

NameDataTypeDescription
storageUnitNameIDENTIFIERStorage unit name
hostnameSTRINGHost or IP
portINTPort
dbNameSTRINGDB name
urlSTRINGURL
userSTRINGusername
passwordSTRINGpassword

Notes

  • Before adding storage unit, please confirm that a distributed database has been created, and execute the use command to successfully select a database;
  • Confirm that the storage unit to be added or altered can be connected, otherwise the operation will not be successful;
  • Duplicate storageUnitName is not allowed;
  • PROPERTIES is used to customize connection pool parameters, key and value are both STRING types;
  • ALTER STORAGE UNIT is not allowed to change the real data source associated with this storage unit;
  • ALTER STORAGE UNIT will switch the connection pool. This operation may affect the ongoing business, please use it with caution;
  • UNREGISTER STORAGE UNIT will only delete logical storage unit, not real data sources;
  • Storage unit referenced by rules cannot be deleted;
  • If the storage unit is only referenced by single table rule, and the user confirms that the restriction can be ignored, the optional parameter ignore single tables can be added to perform forced deletion.

Example

  1. REGISTER STORAGE UNIT ds_0 (
  2.     HOST="127.0.0.1",
  3.     PORT=3306,
  4.     DB="db0",
  5.     USER="root",
  6.     PASSWORD="root"
  7. ),ds_1 (
  8.     HOST="127.0.0.1",
  9.     PORT=3306,
  10.     DB="db1",
  11.     USER="root"
  12. ),ds_2 (
  13.     HOST="127.0.0.1",
  14.     PORT=3306,
  15.     DB="db2",
  16.     USER="root",
  17.     PROPERTIES("maximumPoolSize"="10")
  18. ),ds_3 (
  19.     URL="jdbc:mysql://127.0.0.1:3306/db3?serverTimezone=UTC&useSSL=false",
  20.     USER="root",
  21.     PASSWORD="root",
  22.     PROPERTIES("maximumPoolSize"="10","idleTimeout"="30000")
  23. );
  25. ALTER STORAGE UNIT ds_0 (
  26.     HOST="127.0.0.1",
  27.     PORT=3309,
  28.     DB="db0",
  29.     USER="root",
  30.     PASSWORD="root"
  31. ),ds_1 (
  32.     URL="jdbc:mysql://127.0.0.1:3309/db1?serverTimezone=UTC&useSSL=false",
  33.     USER="root",
  34.     PASSWORD="root",
  35.     PROPERTIES("maximumPoolSize"="10","idleTimeout"="30000")
  36. );
  38. UNREGISTER STORAGE UNIT ds_0, ds_1;
  39. UNREGISTER STORAGE UNIT ds_2, ds_3 ignore single tables;