tCassandraOutputBulk - 6.1

Talend Components Reference Guide

EnrichVersion
6.1
EnrichProdName
Talend Big Data
Talend Big Data Platform
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Talend Data Integration
Talend Data Management Platform
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Talend MDM Platform
Talend Open Studio for Big Data
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task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Warning

This component will be available in the Palette of the studio on the condition that you have subscribed to one of the Talend solutions with Big Data.

The tCassandraOutputBulk and tCassandraBulkExec components are generally used together as parts of a two step process. In the first step, an SSTable is generated. In the second step, this SSTable is written into Cassandra. These two steps are fused together in the tCassandraOutputBulkExec component, detailed in a separate section. The advantage of using two separate components is that the data can be transformed before it is loaded into Cassandra.

tCassandraOutputBulk properties

Component family

Big Data / Cassandra

 

Function

tCassandraOutputBulk receives data from the preceding component, and creates an SSTable locally.

Purpose

tCassandraOutputBulk allows you to prepare an SSTable of large size and process it according to your needs before loading this SSTable into a column family of a Cassandra keyspace.

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.

Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.

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.

When the schema to be reused has default values that are integers or functions, ensure that these default values are not enclosed within quotation marks. If they are, you must remove the quotation marks manually.

For more details, see https://help.talend.com/display/KB/Verifying+default+values+in+a+retrieved+schema.

 

DB Version

Select the Cassandra version you are using.

 

Keyspace

Type in the name of the keyspace into which you want to write the SSTable.

 

Column family

Type in the name of the column family into which you want to write the SSTable.

 

Partitioner

Select the partitioner which determines how data is distributed across the Cassandra cluster.

  • Random: default partitioner in Cassandra 1.1 and earlier.

  • Murmur3: default partitioner in Cassandra 1.2.

  • Order preserving: not recommended because it assumes keys are UTF8 strings.

For more information about the partitioner, see http://wiki.apache.org/cassandra/Partitioners.

 

Column name comparator

Select the data type for the column names, which is used to sort columns.

For more information about the comparators, see http://www.datastax.com/docs/1.1/ddl/column_family#about-data-types-comparators-and-validators.

 

SSTable directory

Specify the local directory for the SSTable. Note that the complete path to the SSTable will be the local directory appended by the specified keyspace name and column family name.

For example, if you set the local directory to /home/talend/sstable, and specify testk as the keyspace name and testc as the column family name, the complete path to the SSTable will be /home/talend/sstable/testk/testc/.

 

Buffer size

Specify what size the SSTable must reach before it is written into Cassandra.

Advanced settings

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

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 always needs an incoming link.

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

Related scenario

No scenario is available for this component yet.