ALTER MIGRATION RULE

Description

The ALTER MIGRATION RULE syntax is used to alter migration rule.

Syntax

Grammar Railroad diagram

AlterMigrationRule ::=
  'ALTER' 'MIGRATION' 'RULE' ('(' (readConfiguration ',')?  (writeConfiguration  ',')? (dataChannel)? ')')?
readConfiguration ::=
  'READ' '(' ('WORKER_THREAD' '=' workerThreadPoolSize ',')? ('BATCH_SIZE' '=' batchSize ',')? ('SHARDING_SIZE' '=' shardingSize ',')? (rateLimiter)? ')'
writeConfiguration ::=
  'WRITE' '(' ('WORKER_THREAD' '=' workerThreadPoolSize ',')? ('BATCH_SIZE' '=' batchSize ',')? ('SHARDING_SIZE' '=' shardingSize ',')? (rateLimiter)? ')'
dataChannel ::=
  'STREAM_CHANNEL' '(' 'TYPE' '(' 'NAME' '=' algorithmName ',' propertiesDefinition ')' ')'
workerThreadPoolSize ::=
  int
batchSize ::=
  int
shardingSize ::=
  int
rateLimiter ::=
  'RATE_LIMITER' '(' 'TYPE' '(' 'NAME' '=' algorithmName ',' propertiesDefinition ')' ')'
algorithmName ::=
  string
propertiesDefinition ::=
  'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'
key ::=
  string
value ::=
  literal

Supplement

• ALTER MIGRATION RULE able to modify only one configuration in the data migration rule without affecting other configurations.

Example

• Alter migration rule

ALTER MIGRATION RULE (
  READ( WORKER_THREAD=20, BATCH_SIZE=1000, SHARDING_SIZE=10000000, RATE_LIMITER (TYPE(NAME='QPS',PROPERTIES('qps'='500')))), 
  WRITE( WORKER_THREAD=20, BATCH_SIZE=1000, RATE_LIMITER (TYPE(NAME='TPS',PROPERTIES('tps'='2000')))), 
  STREAM_CHANNEL ( TYPE(NAME='MEMORY',PROPERTIES('block-queue-size'='2000')))
  );

• Alter read configuration only in migration rule

ALTER MIGRATION RULE (
  READ(WORKER_THREAD=20, BATCH_SIZE=1000, SHARDING_SIZE=10000000, RATE_LIMITER (TYPE(NAME='QPS',PROPERTIES('qps'='500'))))
  );

• Alter write configuration only in migration rule

ALTER MIGRATION RULE (
  WRITE(WORKER_THREAD=20, BATCH_SIZE=1000, SHARDING_SIZE=10000000, RATE_LIMITER (TYPE(NAME='QPS',PROPERTIES('qps'='500'))))
  );

• Alter stream channel configuration in migration rule

ALTER MIGRATION RULE (
  STREAM_CHANNEL ( TYPE( NAME='MEMORY', PROPERTIES('block-queue-size'='2000')))
  );

Reserved word

ALTER, MIGRATION, RULE, READ, WRITE, WORKER_THREAD, BATCH_SIZE, SHARDING_SIZE, STREAM_CHANNEL, TYPE, NAME, PROPERTIES

Related links

• Reserved word