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(warning) PLEASE NOTE: This documentation applies to Pentaho 7.1 and earlier. For Pentaho 8.0 and later, see Avro Output on the Pentaho Enterprise Edition documentation site.

Description

The Avro output step serializes data into Avro binary or JSON format, then writes to file on disk.

This output step creates 2 files:  1) the file containing output data in Avro format and 2) an Avro schema file - defined by the output step "fields"

Fields can be defined manually or extracted from incoming steps.

Options

Main Configuration

Option

Definition

Example

Step name

The name of this step as it appears in the transformation workspace.

 

Location

File system type of where the Avro output data will be written

Local, Hadoop Cluster, S3, HDFS, MapRFS

File name

The fully qualified URL  where the Avro output data will be written.  URL will be of different format depending on file system type (Location field).

file:///C:/avro-output-file _

 

 

Fields Tab

The Fields tab defines the fields that will make up the Avro schema that will be created by this step.  These fields can be defined manually.  Or users can click "Get Fields" button to populate these fields from the incoming PDI stream.

Option

Definition

Example(s)

Avro path

The name of the field as it will appear in the Avro Schema and avro file

 

Name

The name of the PDI field

 

Type

The data type of the field

String, Integer, etc

Default value

The default value of the field if it is null or empty

 

Null

Is this field allowed to have null values?

Yes, No

Get Fields (button)

If user clicks this button, the fields table will be populated with fields from the incoming PDI stream

 

Note

If the "Null" field is set to "No", null values are not allowed for this field. If the incoming data contain null values for such fields, the transformation will fail. To avoid this, make sure the "Default value" field is populated for all fields where "Null" is set to "No".

Schema Tab

The schema tab defines options for how the Avro schema file will be created.  Reference:  https://avro.apache.org/docs/1.8.1/spec.html#schema_record

 

Option

Definition

Example(s)

File Name

The fully qualified URL where the Avro schema file will be written.  URL will be of different format depending on file system type (Location field).  If a schema file already exists, it will be overwritten.  Otherwise, a new file will be created.

_file:///C:/avro-output-schema_

Namespace

Together with the "Record name" field, this defines the "full name" of the schema (example.avro.User in this case).

example.avro

Record name

The name of the Avro record

User

Doc value

provides documentation to the user of this schema

 

Options Tab

The options tab contains additional options you can define for Avro output file / schema.  In this case, there is only 1:  compression.  Reference:  https://avro.apache.org/docs/1.8.1/spec.html#Object+Container+Files

Options

Definition

Example(s)

Compression

the name of the compression codec used to compress blocks in Avro output file

None, Deflate, Snappy

Metadata Injection Support (7.x and later)

All fields of this step support metadata injection. You can use this step with ETL Metadata Injection to pass metadata to your transformation at runtime.

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