tReplicate - 6.1

Talend Components Reference Guide

EnrichVersion
6.1
EnrichProdName
Talend Big Data
Talend Big Data Platform
Talend Data Fabric
Talend Data Integration
Talend Data Management Platform
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for Big Data
Talend Open Studio for Data Integration
Talend Open Studio for Data Quality
Talend Open Studio for ESB
Talend Open Studio for MDM
Talend Real-Time Big Data Platform
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Function

Duplicate the incoming schema into two identical output flows.

Purpose

Allows you to perform different operations on the same schema.

If you have subscribed to one of the Talend solutions with Big Data, this component is available in the following types of Jobs:

tReplicate Properties

Component family

Orchestration

 

Basic settings

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. The schema is either Built-In or stored remotely in the Repository.

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.

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

This component offers the advantage of the dynamic schema feature. This allows you to retrieve unknown columns from source files or to copy batches of columns from a source without mapping each column individually. For further information about dynamic schemas, see Talend Studio User Guide.

This dynamic schema feature is designed for the purpose of retrieving unknown columns of a table and is recommended to be used for this purpose only; it is not recommended for the use of creating tables.

 

 

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.

Global Variables

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage

This component is not startable (green background), it requires an Input component and an output component.

Connections

Outgoing links (from this component to another):

Row: Main.

Trigger: Run if; On Component Ok; On Component Error.

Incoming links (from one component to this one):

Row: Main; Reject;

For further information regarding connections, see Talend Studio User Guide.

Log4j

If you are using a subscription-based version of the Studio, the activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Scenario: Replicating a flow and sorting two identical flows respectively

The scenario describes a Job that reads an input flow which contains names and states from a CSV file, replicates the input flow, then sorts the two identical flows based on name and state respectively, and displays the sorted data on the console.

Setting up the Job

  1. Drop the following components from the Palette to the design workspace: one tFileInputDelimited component, one tReplicate component, two tSortRow components, and two tLogRow components.

  2. Connect tFileInputDelimited to tReplicate using a Row > Main link.

  3. Repeat the step above to connect tReplicate to two tSortRow components respectively and connect tSortRow to tLogRow.

  4. Label the components to better identify their functions.

Configuring the components

  1. Double-click the tFileInputDelimited component to open its Basic settings view in the Component tab.

  2. Click the [...] button next to the File name/Stream field to browse to the file from which you want to read the input flow. In this example, the input file is Names&States.csv, which contains two columns: name and state.

    name;state
    Andrew Kennedy;Mississippi
    Benjamin Carter;Louisiana
    Benjamin Monroe;West Virginia
    Bill Harrison;Tennessee
    Calvin Grant;Virginia
    Chester Harrison;Rhode Island
    Chester Hoover;Kansas
    Chester Kennedy;Maryland
    Chester Polk;Indiana
    Dwight Nixon;Nevada
    Dwight Roosevelt;Mississippi
    Franklin Grant;Nebraska
  3. Fill in the Header, Footer and Limit fields according to your needs. In this example, type in 1 in the Header field to skip the first row of the input file.

  4. Click Edit schema to define the data structure of the input flow.

  5. Double-click the first tSortRow component to open its Basic settings view.

  6. In the Criteria panel, click the [+] button to add one row and set the sorting parameters for the schema column to be processed. To sort the input data by name, select name under Schema column. Select alpha as the sorting type and asc as the sorting order.

    For more information about those parameters, see tSortRow properties.

  7. Double-click the second tSortRow component and repeat the step above to define the sorting parameters for the state column.

  8. In the Basic settings view of each tLogRow component, select Table in the Mode area for a better view of the Job execution result.

Saving and executing the Job

  1. Press Ctrl+S to save your Job.

  2. Execute the Job by pressing F6 or clicking Run on the Run tab.

    The data sorted by name and state are both displayed on the console.

tReplicate in Talend Map/Reduce Jobs

Warning

The information in this section is only for users that have subscribed to one of the Talend solutions with Big Data and is not applicable to Talend Open Studio for Big Data users.

In a Talend Map/Reduce Job, tReplicate, as well as the other Map/Reduce components preceding it, generates native Map/Reduce code. This section presents the specific properties of tReplicate when it is used in that situation. For further information about a Talend Map/Reduce Job, see Talend Big Data Getting Started Guide.

Component family

Processing

 

Basic settings

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. The schema is either Built-In or stored remotely in the Repository.

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.

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

This component offers the advantage of the dynamic schema feature. This allows you to retrieve unknown columns from source files or to copy batches of columns from a source without mapping each column individually. For further information about dynamic schemas, see Talend Studio User Guide.

This dynamic schema feature is designed for the purpose of retrieving unknown columns of a table and is recommended to be used for this purpose only; it is not recommended for the use of creating tables.

 

 

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.

Global Variables

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage in Map/Reduce Jobs

This component is not startable, it requires an Input component and an output component.

In a Talend Map/Reduce Job, this component is used as an intermediate step and other components used along with it must be Map/Reduce components, too. They generate native Map/Reduce code that can be executed directly in Hadoop.

For further information about a Talend Map/Reduce Job, see the sections describing how to create, convert and configure a Talend Map/Reduce Job of the Talend Big Data Getting Started Guide.

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

Connections

Outgoing links (from this component to another):

Row: Main.

Trigger: Run if; On Component Ok; On Component Error.

Incoming links (from one component to this one):

Row: Main; Reject;

For further information regarding connections, see Talend Studio User Guide.

Related scenarios

No scenario is available for the Map/Reduce version of this component yet.

tReplicate properties in Spark Batch Jobs

Component family

Processing

 

Basic settings

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. The schema is either Built-In or stored remotely in the Repository.

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.

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

 

 

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.

 

Cache replicated RDD

Select this check box to store the replicated RDD in the cache.

From the Storage level drop-down list that is displayed, select how the cached RDDs are stored, such as in memory only or in memory and on disk.

For further information about each of the storage level, see https://spark.apache.org/docs/latest/programming-guide.html#rdd-persistence.

Usage in Spark Batch Jobs

In a Talend Spark Batch Job, this component is used as an intermediate step and other components used along with it must be Spark Batch components, too. They generate native Spark Batch code that can be executed directly in a Spark cluster.

This component, along with the Spark Batch component Palette it belongs to, appears only when you are creating a Spark Batch 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, one and only one file system related component from the Storage family is required in the same Job so that Spark can use this component to connect to the file system to which the jar files dependent on the Job are transferred:

This connection is effective on a per-Job basis.

Log4j

If you are using a subscription-based version of the Studio, the activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Related scenarios

No scenario is available for the Spark Batch version of this component yet.

tReplicate properties in Spark Streaming Jobs

Warning

The streaming version of this component is available in the Palette of the studio on the condition that you have subscribed to Talend Real-time Big Data Platform or Talend Data Fabric.

Component family

Processing

 

Basic settings

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. The schema is either Built-In or stored remotely in the Repository.

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.

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

 

 

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.

 

Cache replicated RDD

Select this check box to store the replicated RDD in the cache.

From the Storage level drop-down list that is displayed, select how the cached RDDs are stored, such as in memory only or in memory and on disk.

For further information about each of the storage level, see https://spark.apache.org/docs/latest/programming-guide.html#rdd-persistence.

Usage in Spark Streaming Jobs

In a Talend Spark Streaming Job, this component is used as an intermediate step and other components used along with it must be Spark Streaming components, too. They generate native Spark Streaming code that can be executed directly in a Spark cluster.

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, one and only one file system related component from the Storage family is required in the same Job so that Spark can use this component to connect to the file system to which the jar files dependent on the Job are transferred:

This connection is effective on a per-Job basis.

Log4j

If you are using a subscription-based version of the Studio, the activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Related scenarios

No scenario is available for the Spark Streaming version of this component yet.

tReplicate in Talend Storm Jobs

Warning

The information in this section is only for users that have subscribed to one of the Talend solutions with Big Data and is not applicable to Talend Open Studio for Big Data users.

In a Talend Storm Job, tReplicate, as well as the other Storm components preceding it, generates native Storm code. This section presents the specific properties of tReplicate when it is used in that situation. For further information about a Talend Storm Job, see Talend Big Data Getting Started Guide.

Component family

Processing

 

Basic settings

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. The schema is either Built-In or stored remotely in the Repository.

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.

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

This component offers the advantage of the dynamic schema feature. This allows you to retrieve unknown columns from source files or to copy batches of columns from a source without mapping each column individually. For further information about dynamic schemas, see Talend Studio User Guide.

This dynamic schema feature is designed for the purpose of retrieving unknown columns of a table and is recommended to be used for this purpose only; it is not recommended for the use of creating tables.

 

 

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.

Usage in Storm Jobs

This component is not startable, it requires an Input component and an output component.

If you have subscribed to one of the Talend solutions with Big Data, you can also use this component as a Storm component. In a Talend Storm Job, this component is used as an intermediate step and other components used along with it must be Storm components, too. They generate native Storm code that can be executed directly in a Storm system.

The Storm version does not support the use of the global variables.

You need to use the Storm Configuration tab in the Run view to define the connection to a given Storm system for the whole Job.

This connection is effective on a per-Job basis.

For further information about a Talend Storm Job, see the sections describing how to create and configure a Talend Storm Job of the Talend Big Data Getting Started Guide.

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

Connections

Outgoing links (from this component to another):

Row: Main.

Trigger: Run if; On Component Ok; On Component Error.

Incoming links (from one component to this one):

Row: Main; Reject;

For further information regarding connections, see Talend Studio User Guide.

Related scenarios

No scenario is available for the Storm version of this component yet.