Put transform API

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Creates a new transform.

The API accepts a PutDataFrameTransformRequest object as a request and returns a AcknowledgedResponse.

Put transform request

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A PutDataFrameTransformRequest requires the following argument:

PutDataFrameTransformRequest request =
        new PutDataFrameTransformRequest(transformConfig); 

The configuration of the transform to create

Transform configuration

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The DataFrameTransformConfig object contains all the details about the transform configuration and contains the following arguments:

DataFrameTransformConfig transformConfig = DataFrameTransformConfig
    .builder()
    .setId("reviewer-avg-rating") 
    .setSource(sourceConfig) 
    .setDest(new DestConfig("pivot-destination")) 
    .setPivotConfig(pivotConfig) 
    .setDescription("This is my test transform") 
    .build();

The transform ID

The source indices and query from which to gather data

The destination index

The PivotConfig

Optional free text description of the transform

SourceConfig

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The indices and the query from which to collect data. If query is not set, a match_all query is used by default.

SourceConfig sourceConfig = SourceConfig.builder()
    .setIndex("source-index")
    .setQueryConfig(queryConfig).build();

QueryConfig

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The query with which to select data from the source.

QueryConfig queryConfig = new QueryConfig(new MatchAllQueryBuilder());

PivotConfig

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Defines the pivot function group by fields and the aggregation to reduce the data.

PivotConfig pivotConfig = PivotConfig.builder()
    .setGroups(groupConfig) 
    .setAggregationConfig(aggConfig) 
    .setMaxPageSearchSize(1000) 
    .build();

The GroupConfig to use in the pivot

The aggregations to use

The maximum paging size for the transform when pulling data from the source. The size dynamically adjusts as the transform is running to recover from and prevent OOM issues.

GroupConfig

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The grouping terms. Defines the group by and destination fields which are produced by the pivot function. There are 3 types of groups

  • Terms
  • Histogram
  • Date Histogram
GroupConfig groupConfig = GroupConfig.builder()
    .groupBy("reviewer", 
        TermsGroupSource.builder().setField("user_id").build()) 
    .build();

The destination field

Group by values of the user_id field

AggregationConfig

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Defines the aggregations for the group fields.

AggregatorFactories.Builder aggBuilder = new AggregatorFactories.Builder();
aggBuilder.addAggregator(
        AggregationBuilders.avg("avg_rating").field("stars"));  
AggregationConfig aggConfig = new AggregationConfig(aggBuilder);

Aggregate the average star rating

Synchronous execution

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When executing a PutDataFrameTransformRequest in the following manner, the client waits for the AcknowledgedResponse to be returned before continuing with code execution:

AcknowledgedResponse response =
        client.dataFrame().putDataFrameTransform(
                request, RequestOptions.DEFAULT);

Synchronous calls may throw an IOException in case of either failing to parse the REST response in the high-level REST client, the request times out or similar cases where there is no response coming back from the server.

In cases where the server returns a 4xx or 5xx error code, the high-level client tries to parse the response body error details instead and then throws a generic ElasticsearchException and adds the original ResponseException as a suppressed exception to it.

Asynchronous execution

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Executing a PutDataFrameTransformRequest can also be done in an asynchronous fashion so that the client can return directly. Users need to specify how the response or potential failures will be handled by passing the request and a listener to the asynchronous put-transform method:

client.dataFrame().putDataFrameTransformAsync(
        request, RequestOptions.DEFAULT, listener); 

The PutDataFrameTransformRequest to execute and the ActionListener to use when the execution completes

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed. Failure scenarios and expected exceptions are the same as in the synchronous execution case.

A typical listener for put-transform looks like:

ActionListener<AcknowledgedResponse> listener =
        new ActionListener<AcknowledgedResponse>() {
    @Override
    public void onResponse(AcknowledgedResponse response) {
        
    }

    @Override
    public void onFailure(Exception e) {
        
    }
};

Called when the execution is successfully completed.

Called when the whole PutDataFrameTransformRequest fails.

Response

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The returned AcknowledgedResponse acknowledges the successful creation of the new transform or an error if the configuration is invalid.