tMatchIndexPredict properties for Apache Spark Streaming

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 be processed and passed on to the next component. When you create a Spark Job, avoid the reserved word line when naming the fields.

Click Sync columns to retrieve the schema from the previous component connected in the Job.

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.

You need to manually edit the output schema to add the necessary columns that hold the fields from the lookup data.

The output schema of this component contains read-only columns:

LABEL: used only with the Possible matches output link.

CONFIDENCE_SCORE: indicates the confidence score of a prediction for a pair.

ElasticSearch configuration

Nodes: Enter the location of the cluster hosting the ElasticSearch system to be used.

Index: Enter the name of the ElasticSearch index where the lookup data is stored.

Note that the Talend components support the Elasticsearch 6.4.x version for Spark Streaming Jobs, and Elasticsearch 7.x and 8.x versions for Spark Batch Jobs.

Models

Pairing model folder: Set the path to the folder which has the model files generated by the tMatchPairing component.

Matching model location: Select from file system to get the model file generated by the classification Job with the tMatchModel component.

Matching model folder: Set the path to the folder which has the model files generated by the tMatchModel component.

No-match label: Enter the label used for the unique records in the output.

If you want to store the model in a specific file system, for example S3 or HDFS, you must use the corresponding component in the Job and select the Define a storage configuration component check box in the component basic settings.

The button for browsing does not work with the Spark Local mode; if you are using the other Spark Yarn modes that Talend Studio supports with your distribution, ensure that you have properly configured the connection in a configuration component in the same Job. Use the configuration component depending on the filesystem to be used.

Maximum ElasticSearch bulk size

Maximum number of records for bulk processing.

tMatchIndexPredict uses bulk mode to process data so that big batches of data can be quickly compared with lookup data indexed in ElasticSearch.

It is recommended to leave the default value. If the Job execution ends with an error, reduce the value for this parameter.

It is recommended to leave the default value. A lower value may cause a timeout error.

Usage rule

This component is used as an intermediate step.

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

Spark Connection

This connection is effective on a per-Job basis.