tTop MapReduce properties (deprecated)
These properties are used to configure tTop running in the MapReduce Job framework.
The MapReduce tTop component belongs to the Processing family.
The component in this framework is available in all Talend products with Big Data and Talend Data Fabric.
The MapReduce framework is deprecated from Talend 7.3 onwards. Use Talend Jobs for Apache Spark to accomplish your integration tasks.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. 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:
Click Sync columns to retrieve the schema from the previous component connected in the Job. |
|
Built-In: You create and store the schema locally for this component only. |
|
Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. |
Number of line selected |
Enter the number of rows to be outputted. The current component selects this number of rows down from the first rows of the sorted data. |
Criteria |
Click [+] to add as many lines as required for the sort to be completed. |
|
In the Schema column column, select the column from your schema, which the sort will be based on. Note that the order is essential as it determines the sorting priority. |
|
In the other columns, select how you need the data to be sorted. For example, if you need to sort the data in ascending alphabetical order (from A to Z), select alpha and asc in the corresponding columns. |
Usage
Usage rule |
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. This connection is effective on a per-Job basis. 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. |
Hadoop Connection |
You need to use the Hadoop Configuration tab in the Run view to define the connection to a given Hadoop distribution for the whole Job. This connection is effective on a per-Job basis. |