This is the main documentation for the gora-kudu module. gora-kudu module enables Apache Kudu backend support for Gora.

Gora Kudu Properties - gora.properties

Gora Kudu mappings - gora-kudu-mapping.xml

You should then create a gora-kudu-mapping.xml which will describe how you want to store each of your Gora persistent objects and which primary keys you want to use:

	<table name ="Employee">
		<primaryKey column="pkssn" type="STRING" />
		<hashPartition numBuckets="8"/>
	<class name="org.apache.gora.examples.generated.Employee" keyClass="java.lang.String" table="Employee">
		<field name="ssn" column="ssn" type="STRING"/>
		<field name="value" column="value" type="STRING"/>
		<field name="name" column="name" type="STRING"/>
		<field name="dateOfBirth" column="dateOfBirth" type="INT64"/>
		<field name="salary" column="salary" type="INT32"/>
		<field name="boss" column="boss" type="BINARY"/>
		<field name="webpage" column="webpage" type="BINARY"/>

Here you can see that we require the definition of two child elements within the gora-otd mapping configuration: a class and a table.


Each class element should contain the following elements;

  1. a parameter defining the Persistent class name e.g. org.apache.gora.examples.generated.Employee,

  2. a parameter defining the keyClass e.g. java.lang.String which specifies the key which maps to the field values,

  3. a parameter defining the table e.g. Employee which will be used to persist each Gora object

In addition, within the class element we should define the fields to be mapped (field tag). The fields elements define the actual mapping between persistent object's attributes and the table's columns. These mapping have three customizable parameters: name which correspond to the object attribute's name. column which defines the column's name of the table to be associated with the attribute. And type which defines the data type of that column.


Each table element should contain the following elements;

  1. A primaryKey element defining which column is used by Kudu to identify the records stored in the DataStore. It has two attributes: column which defines the column's name of the table to be used as identifier for the records, and type which defines the data type of the aforementioned column.

  2. A partition definition for the table, which could be either a hash partition or a range partition. For more information about Partitioning in Kudu refer to https://kudu.apache.org/docs/schema_design.html#partitioning


Example for Hash partition:

    <hashPartition numBuckets="8"/>

The numBuckets attribute specifies the number of hash buckets to be used as partitions.

Example for Range partition:

    <rangePartition lower="" upper ="1000"/>

    <rangePartition lower="1000" upper =""/>

The lower and upper attributes define the boundaries of each partition. This partition is applied only on the primary key column of the table. Take into consideration that the lower bound is inclusive and the upper one is not.

Supported Data types

Description of supported type values:

Kudu datatype Java datatype
BOOL boolean
INT8 byte
INT32 short
INT16 int
INT64 long
UNIXTIME_MICROS java.sql.Timestamp
FLOAT float
DOUBLE double
DECIMAL BigDecimal
BINARY byte[]

For more details about supported data types refer to https://kudu.apache.org/docs/schema_design.html#column-design