Write to Iceberg using dynamic destinations

Write from Dataflow to Apache Iceberg, using the dynamic destinations feature to route incoming records to different Iceberg tables. (Note, currently this feature is only supported for Java)

Explore further

For detailed documentation that includes this code sample, see the following:

• Write from Dataflow to Apache Iceberg

Code sample

Java

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import com.google.common.collect.ImmutableMap;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.managed.Managed;
import org.apache.beam.sdk.options.Description;
import org.apache.beam.sdk.options.PipelineOptions;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.schemas.Schema;
import org.apache.beam.sdk.transforms.Create;
import org.apache.beam.sdk.transforms.JsonToRow;

public class ApacheIcebergDynamicDestinations {

  // The schema for the table rows.
  public static final Schema SCHEMA = new Schema.Builder()
      .addInt64Field("id")
      .addStringField("name")
      .addStringField("airport")
      .build();

  // The data to write to table, formatted as JSON strings.
  static final List<String> TABLE_ROWS = List.of(
      "{\"id\":0, \"name\":\"Alice\", \"airport\": \"ORD\" }",
      "{\"id\":1, \"name\":\"Bob\", \"airport\": \"SYD\" }",
      "{\"id\":2, \"name\":\"Charles\", \"airport\": \"ORD\" }"
  );

  public interface Options extends PipelineOptions {
    @Description("The URI of the Apache Iceberg warehouse location")
    String getWarehouseLocation();

    void setWarehouseLocation(String value);

    @Description("The name of the Apache Iceberg catalog")
    String getCatalogName();

    void setCatalogName(String value);
  }

  // Write JSON data to Apache Iceberg, using dynamic destinations to determine the Iceberg table
  // where Dataflow writes each record. The JSON data contains a field named "airport". The
  // Dataflow pipeline writes to Iceberg tables with the naming pattern "flights-{airport}".
  public static void main(String[] args) {
    // Parse the pipeline options passed into the application. Example:
    //   --runner=DirectRunner --warehouseLocation=$LOCATION --catalogName=$CATALOG \
    // For more information, see https://beam.apache.org/documentation/programming-guide/#configuring-pipeline-options
    Options options = PipelineOptionsFactory.fromArgs(args).withValidation().as(Options.class);
    Pipeline pipeline = Pipeline.create(options);

    // Configure the Iceberg source I/O
    Map catalogConfig = ImmutableMap.<String, Object>builder()
        .put("warehouse", options.getWarehouseLocation())
        .put("type", "hadoop")
        .build();

    ImmutableMap<String, Object> config = ImmutableMap.<String, Object>builder()
        .put("catalog_name", options.getCatalogName())
        .put("catalog_properties", catalogConfig)
        // Route the incoming records based on the value of the "airport" field.
        .put("table", "flights-{airport}")
        // Specify which fields to keep from the input data.
        .put("keep", Arrays.asList("name", "id"))
        .build();

    // Build the pipeline.
    pipeline
        // Read in-memory JSON data.
        .apply(Create.of(TABLE_ROWS))
        // Convert the JSON records to Row objects.
        .apply(JsonToRow.withSchema(SCHEMA))
        // Write each Row to Apache Iceberg.
        .apply(Managed.write(Managed.ICEBERG).withConfig(config));

    // Run the pipeline.
    pipeline.run().waitUntilFinish();
  }
}

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