tFileOutputJSON properties for Apache Spark Streaming

JSON

author
Talend Documentation Team
EnrichVersion
6.5
EnrichProdName
Talend Open Studio for Big Data
Talend Open Studio for Data Integration
Talend MDM Platform
Talend Real-Time Big Data Platform
Talend Data Services Platform
Talend Data Fabric
Talend Big Data
Talend Big Data Platform
Talend Data Integration
Talend Open Studio for ESB
Talend Data Management Platform
Talend Open Studio for MDM
Talend ESB
task
Data Governance > Third-party systems > File components (Integration) > JSON components
Design and Development > Third-party systems > File components (Integration) > JSON components
Data Quality and Preparation > Third-party systems > File components (Integration) > JSON components
EnrichPlatform
Talend Studio

These properties are used to configure tFileOutputJSON running in the Spark Streaming Job framework.

The Spark Streaming tFileOutputJSON component belongs to the File family.

The component in this framework is available in Talend Real Time Big Data Platform and Talend Data Fabric.

Basic settings

Define a storage configuration component

Select the configuration component to be used to provide the configuration information for the connection to the target file system such as HDFS.

If you leave this check box clear, the target file system is the local system.

The configuration component to be used must be present in the same Job. For example, if you have dropped a tHDFSConfiguration component in the Job, you can select it to write the result in a given HDFS system.

Schema and Edit Schema

A schema is a row description. It defines the number of fields (columns) to Repository. When you create a Spark Job, avoid the reserved word line when naming the fields.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

  • View schema: choose this option to view the schema only.

  • Change to built-in property: choose this option to change the schema to Built-in for local changes.

  • Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window.

 

Built-In: You create and store the schema locally for this component only. Related topic: see Talend Studio User Guide.

 

Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. Related topic: see Talend Studio User Guide.

Folder

Browse to, or enter the path pointing to the data to be used in the file system.

Note that this path must point to a folder rather than a file.

The button for browsing does not work with the Spark Local mode; if you are using the Spark Yarn or the Spark Standalone mode, ensure that you have properly configured the connection in a configuration component in the same Job, such as tHDFSConfiguration.

Output type

Select the structure for the JSON output file(s).

  • All in one block: the received data will be written into one data block.

  • One row per record: the received data will be written into separate data blocks row by row.

Name of data block

Type in the name of the data block for the JSON output file(s).

This field will be available only if you select All in one block from the Output type list.

Action

Select the action that you want to perform on the data:

  • Overwrite: the data on HDFS will be overwritten if it already exists.

  • Create: the data will be created.

Advanced settings

Write empty batches Select this check box to allow your Spark Job to create an empty batch when the incoming batch is empty.

For further information about when this is desirable behavior, see this discussion.

Use local timezone for date Select this check box to use the local date of the machine in which your Job is executed. If leaving this check box clear, UTC is automatically used to format the Date-type data.

Usage

Usage rule

This component is used as an end component and requires an input link.

This component, along with the Spark Streaming component Palette it belongs to, appears only when you are creating a Spark Streaming Job.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents only Standard Jobs, that is to say traditional Talend data integration Jobs.

Spark Connection

You need to use the Spark Configuration tab in the Run view to define the connection to a given Spark cluster for the whole Job. In addition, since the Job expects its dependent jar files for execution, you must specify the directory in the file system to which these jar files are transferred so that Spark can access these files:
  • Yarn mode: when using Google Dataproc, specify a bucket in the Google Storage staging bucket field in the Spark configuration tab; when using other distributions, use a tHDFSConfiguration component to specify the directory.

  • Standalone mode: you need to choose the configuration component depending on the file system you are using, such as tHDFSConfiguration or tS3Configuration.

This connection is effective on a per-Job basis.