tPartitioner Properties - 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
EnrichPlatform
Talend Studio
task
Data Governance
Data Quality and Preparation
Design and Development

Component family

Orchestration

 

Function

This component splits the input records into a given number of threads which tCollector sends for parallel execution.

Purpose

This component partitions the input data before tCollector can transfer them to the parallel execution processes.

Basic settings

Schema and Edit Schema

A schema is a row description, it defines the number of fields 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 connected in the Job.

 

 Number of Child Threads

Enter the number of threads you want to split the input records up into.

We recommend that this number be N-1 where N is the total number of CPUs or cores on the machine processing the data.

 

Buffer Size

Enter the number of rows to be processed before the memory is freed.

This is the number of rows to cache for each of the threads generated.

 

Use a key hash for partitions

Select this check box to use the hash mode to dispatch the input records into threads.

Once selecting it, the Key Columns table appears, in which you set the column(s) you want to apply the hash mode on. In the hash mode, the records meeting the same criteria are dispatched into the same threads.

If you leave this check box clear, the dispatch mode is Round-robin, meaning records are dispatched one-by-one to each thread, in a circular fashion, until the last record is dispatched. Be aware that this mode cannot guarantee that records meeting the same criteria go into the same threads.

Advanced settings

tStatCatcher Statistics

Select this check box to collect the log data at the component level.

Usage

This component should be put after the input component(s) and before tCollector.

This component uses and can only use the Trigger > Start link to connect to tCollector.

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.

NB_LINE: the number of rows processed. This is an After variable and it returns an integer.

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.

Connections

Outgoing links (from this component to another):

Trigger: Start.

Incoming links (from one component to this one):

Row: Main.

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.

Limitation

n/a