ApsaraDB for HBase:Features

Features

Lindorm Streams publishes messages to topics of Message Queue for Apache Kafka based on the following rules:

• Lindorm Streams records operations that are performed on the same row in the order in which these operations are performed. This way, the recorded operations can be re-performed in the same order.

• The At-least-once semantics is supported. Messages can be consumed multiple times based on the retry policy that you configure. If you want to specify the exactly-once semantics, submit a ticket.

Message format

A Lindorm Streams message can contain two versions of an updated row: the version before the row is updated and the version after the row is updated. The following example shows the content of a message:

{
  "op" : <opType>             // The operation that is performed. Valid values: Put and DeleteFamily.
  "table" : <tableName>       // The name of the table.
  "ts" : <defaultVersion>     // The default version. The default version is used if the row does not contain the ts key.
  "keyOnly":<keyOnly>         // Indicates whether only the primary key is included.
  "data" : [
    {
      "type" : <type>          // The data type of the column.
      "name" : <name>          // The name of the column.
      "ts" : <version>         // The data version. If this parameter is empty, the dts value is used as the version.
      "value" : <value>        // The value of the column. If this parameter is empty, the actual value in the table is null.
  },
  {
      "type" : <type>          // The data type of the column.
      "name" : <name>          // The name of the column.
      "ts" : <version>         // The data version. If this parameter is empty, the dts value is used as the version.
      "value" : <value>        // The value of the column. If this parameter is empty, the actual value in the table is null.
  }
  ]
}

The following table describes the parameters that you can specify for Lindorm Streams messages.