Batch Merger


This stage generates a group tag for each record in the current batch based on the specified condition. The records are then merged with the same tag and output in a single record. The function of this stage includes:

  • Supporting 2 methods for generating group keys: by record field value or EL expression.

Configuration

The configuration tabs for this stage are General, Basic, Input/Output, and Group Key.

General

Name Required? Description
Name Yes The name of the stage.
Description No The description of the stage.
Stage Library Yes The streaming operator library to which the stage belongs.
Required Fields No The fields that the data records must contain. If the specified fields are not included, the record will be filtered out.
Preconditions No The conditions that must be satisfied by the data records. Records that do not meet the conditions will be filtered out. For example, ${record:value('/value') > 0}. For the syntax of EL expressions, see Expression Language.
On Record Error Yes

The processing method for error data.

  • Discard: Error data will be discarded and ignored
  • Send to Error: Error messages will be reported
  • Stop Pipeline: The pipeline will be stopped

Basic

Name Required? Description
Quality Filter No Filter the data according to the data quality. Only records that meet the quality conditions will be processed by this stage.

Input/Output

Name Required? Description
Input Point Yes Specify the input point of the records, using the format {modelId}::{pointId}.
Output Point Yes Specify the output point of the records, using the format {modelId}::{pointId}.

Group Key

Name Required? Description
Key Generate Method Yes Select the method for generating group tags. The options are By Record Field Value and By EL Expression.
Fields No When By Record Field Value is selected, select or specify the field name.
EL Expression No When By EL Expression is selected, type the expression for generating the group keys.

Output Results

The output results of this stage are included in the attr struct. The description of the fields are as follows:

Name Data Type Description
crossBatch Map The collection of records with the same group key.

Output Example

../../../_images/cross_batch_merger.png