Testo Cloud Storage a BigQuery (flusso) con modello UDF Python

La pipeline Testo di Cloud Storage in BigQuery è una pipeline di inserimento flussi che inserisce flussi di file di testo archiviati in Cloud Storage, li trasforma utilizzando una funzione definita dall'utente (UDF) di Python fornita e aggiunge il risultato a BigQuery.

La pipeline viene eseguita a tempo indeterminato e deve essere terminata manualmente tramite un annullamento e non un svuotamento, a causa dell'utilizzo della trasformazione Watch, che è un DoFn suddividibile che non supporta lo svuotamento.

Requisiti della pipeline

  • Crea un file JSON che descriva lo schema della tabella di output in BigQuery.

    Assicurati che esista un array JSON di primo livello denominato fields e che i suoi contenuti rispettino il pattern {"name": "COLUMN_NAME", "type": "DATA_TYPE"}. Ad esempio:

    {
      "fields": [
        {
          "name": "name",
          "type": "STRING"
        },
        {
          "name": "age",
          "type": "INTEGER"
        }
      ]
    }
  • Crea un file Python (.py) con la tua funzione UDF che fornisca la logica per trasformare le righe di testo. La funzione deve restituire una stringa JSON.

    L'esempio seguente suddivide ogni riga di un file CSV, crea un oggetto JSON con i valori e restituisce una stringa JSON:

    import json
    def process(value):
      data = value.split(',')
      obj = { 'name': data[0], 'age': int(data[1]) }
      return json.dumps(obj)

Parametri del modello

Parametro Descrizione
pythonExternalTextTransformGcsPath L'URI di Cloud Storage del file di codice Python che definisce la funzione definita dall'utente (UDF) che vuoi utilizzare. Ad esempio, gs://my-bucket/my-udfs/my_file.py.
pythonExternalTextTransformFunctionName Il nome della funzione definita dall'utente (UDF) di Python che vuoi utilizzare.
JSONPath Posizione Cloud Storage del file di schema BigQuery, descritto come JSON. Ad esempio: gs://path/to/my/schema.json.
outputTable La tabella BigQuery completamente qualificata. Ad esempio: my-project:dataset.table
inputFilePattern Posizione di Cloud Storage del testo che vuoi elaborare. Ad esempio: gs://my-bucket/my-files/text.txt.
bigQueryLoadingTemporaryDirectory Directory temporanea per il processo di caricamento di BigQuery. Ad esempio: gs://my-bucket/my-files/temp_dir
outputDeadletterTable Tabella per i messaggi che non sono riusciti a raggiungere la tabella di output. Ad esempio: my-project:dataset.my-unprocessed-table. Se non esiste, viene creato durante l'esecuzione della pipeline. Se non specificato, viene utilizzato <outputTableSpec>_error_records.

Funzione definita dall'utente

Questo modello richiede una UDF che analizzi i file di input, come descritto in Requisiti della pipeline. Il modello chiama la UDF per ogni riga di testo in ogni file di input. Per ulteriori informazioni sulla creazione di funzioni definite dall'utente, consulta Creare funzioni definite dall'utente per i modelli Dataflow.

Specifiche della funzione

La UDF ha la seguente specifica:

  • Input: una singola riga di testo di un file di input.
  • Output: una stringa JSON che corrisponde allo schema della tabella di destinazione BigQuery.

Esegui il modello

  1. Vai alla pagina Crea job da modello di Dataflow.
  2. Vai a Crea job da modello
  3. Nel campo Nome job, inserisci un nome univoco per il job.
  4. (Facoltativo) Per Endpoint a livello di regione, seleziona un valore dal menu a discesa. La regione predefinita è us-central1.

    Per un elenco delle regioni in cui puoi eseguire un job Dataflow, consulta Località di Dataflow.

  5. Nel menu a discesa Modello di flusso di dati, seleziona the Cloud Storage Text to BigQuery (Stream) with Python UDF template.
  6. Nei campi dei parametri forniti, inserisci i valori dei parametri.
  7. Fai clic su Esegui job.

Nella shell o nel terminale, esegui il modello:

gcloud dataflow flex-template run JOB_NAME \
    --template-file-gcs-location gs://dataflow-templates-REGION_NAME/VERSION/flex/Stream_GCS_Text_to_BigQuery_Xlang \
    --region REGION_NAME \
    --staging-location STAGING_LOCATION \
    --parameters \
pythonExternalTextTransformGcsPath=PATH_TO_PYTHON_UDF_FILE,\
pythonExternalTextTransformFunctionName=PYTHON_FUNCTION,\
JSONPath=PATH_TO_BIGQUERY_SCHEMA_JSON,\
inputFilePattern=PATH_TO_TEXT_DATA,\
outputTable=BIGQUERY_TABLE,\
outputDeadletterTable=BIGQUERY_UNPROCESSED_TABLE,\
bigQueryLoadingTemporaryDirectory=PATH_TO_TEMP_DIR_ON_GCS

Sostituisci quanto segue:

  • JOB_NAME: un nome di job univoco a tua scelta
  • REGION_NAME: la regione in cui vuoi eseguire il deployment del job Dataflow, ad esempio us-central1
  • VERSION: la versione del modello che vuoi utilizzare

    Puoi utilizzare i seguenti valori:

  • STAGING_LOCATION: la posizione per l'organizzazione in anteprima dei file locali (ad esempio gs://your-bucket/staging)
  • PYTHON_FUNCTION: il nome della funzione definita dall'utente (UDF) di Python che vuoi utilizzare.
  • PATH_TO_BIGQUERY_SCHEMA_JSON: il percorso di Cloud Storage al file JSON contenente la definizione dello schema
  • PATH_TO_PYTHON_UDF_FILE: l'URI Cloud Storage del file di codice Python che definisce la funzione definita dall'utente (UDF) che vuoi utilizzare. Ad esempio, gs://my-bucket/my-udfs/my_file.py.
  • PATH_TO_TEXT_DATA: il percorso di Cloud Storage al tuo set di dati di testo
  • BIGQUERY_TABLE: il nome della tabella BigQuery
  • BIGQUERY_UNPROCESSED_TABLE: il nome della tabella BigQuery per i messaggi non elaborati
  • PATH_TO_TEMP_DIR_ON_GCS: il percorso di Cloud Storage alla directory temporanea

Per eseguire il modello utilizzando l'API REST, invia una richiesta POST HTTP. Per ulteriori informazioni sull'API e sui relativi ambiti di autorizzazione, consulta projects.templates.launch.

POST https://dataflow.googleapis.com/v1b3/projects/PROJECT_ID/locations/LOCATION/flexTemplates:launch
{
   "launch_parameter": {
      "jobName": "JOB_NAME",
      "parameters": {
       "pythonExternalTextTransformFunctionName": "PYTHON_FUNCTION",
       "JSONPath": "PATH_TO_BIGQUERY_SCHEMA_JSON",
       "pythonExternalTextTransformGcsPath": "PATH_TO_PYTHON_UDF_FILE",
       "inputFilePattern":"PATH_TO_TEXT_DATA",
       "outputTable":"BIGQUERY_TABLE",
       "outputDeadletterTable":"BIGQUERY_UNPROCESSED_TABLE",
       "bigQueryLoadingTemporaryDirectory": "PATH_TO_TEMP_DIR_ON_GCS"
      },
      "containerSpecGcsPath": "gs://dataflow-templates-LOCATION/VERSION/flex/Stream_GCS_Text_to_BigQuery_Xlang",
   }
}

Sostituisci quanto segue:

  • PROJECT_ID: l'ID del progetto Google Cloud in cui vuoi eseguire il job Dataflow
  • JOB_NAME: un nome di job univoco a tua scelta
  • LOCATION: la regione in cui vuoi eseguire il deployment del job Dataflow, ad esempio us-central1
  • VERSION: la versione del modello che vuoi utilizzare

    Puoi utilizzare i seguenti valori:

  • STAGING_LOCATION: la posizione per l'organizzazione in anteprima dei file locali (ad esempio gs://your-bucket/staging)
  • PYTHON_FUNCTION: il nome della funzione definita dall'utente (UDF) di Python che vuoi utilizzare.
  • PATH_TO_BIGQUERY_SCHEMA_JSON: il percorso di Cloud Storage al file JSON contenente la definizione dello schema
  • PATH_TO_PYTHON_UDF_FILE: l'URI Cloud Storage del file di codice Python che definisce la funzione definita dall'utente (UDF) che vuoi utilizzare. Ad esempio, gs://my-bucket/my-udfs/my_file.py.
  • PATH_TO_TEXT_DATA: il percorso di Cloud Storage al tuo set di dati di testo
  • BIGQUERY_TABLE: il nome della tabella BigQuery
  • BIGQUERY_UNPROCESSED_TABLE: il nome della tabella BigQuery per i messaggi non elaborati
  • PATH_TO_TEMP_DIR_ON_GCS: il percorso di Cloud Storage alla directory temporanea
Java
/*
 * Copyright (C) 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.google.cloud.teleport.v2.templates;

import com.google.api.client.json.JsonFactory;
import com.google.api.services.bigquery.model.TableRow;
import com.google.cloud.teleport.metadata.MultiTemplate;
import com.google.cloud.teleport.metadata.Template;
import com.google.cloud.teleport.metadata.TemplateCategory;
import com.google.cloud.teleport.metadata.TemplateParameter;
import com.google.cloud.teleport.v2.coders.FailsafeElementCoder;
import com.google.cloud.teleport.v2.common.UncaughtExceptionLogger;
import com.google.cloud.teleport.v2.options.BigQueryStorageApiStreamingOptions;
import com.google.cloud.teleport.v2.templates.TextToBigQueryStreaming.TextToBigQueryStreamingOptions;
import com.google.cloud.teleport.v2.transforms.BigQueryConverters.FailsafeJsonToTableRow;
import com.google.cloud.teleport.v2.transforms.ErrorConverters.WriteStringMessageErrors;
import com.google.cloud.teleport.v2.transforms.JavascriptTextTransformer.FailsafeJavascriptUdf;
import com.google.cloud.teleport.v2.transforms.PythonExternalTextTransformer;
import com.google.cloud.teleport.v2.transforms.PythonExternalTextTransformer.RowToStringFailsafeElementFn;
import com.google.cloud.teleport.v2.utils.BigQueryIOUtils;
import com.google.cloud.teleport.v2.utils.GCSUtils;
import com.google.cloud.teleport.v2.utils.ResourceUtils;
import com.google.cloud.teleport.v2.values.FailsafeElement;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.coders.CoderRegistry;
import org.apache.beam.sdk.coders.StringUtf8Coder;
import org.apache.beam.sdk.extensions.gcp.util.Transport;
import org.apache.beam.sdk.io.TextIO;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO.Write.CreateDisposition;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO.Write.WriteDisposition;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryInsertError;
import org.apache.beam.sdk.io.gcp.bigquery.InsertRetryPolicy;
import org.apache.beam.sdk.io.gcp.bigquery.WriteResult;
import org.apache.beam.sdk.options.Default;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.options.ValueProvider.StaticValueProvider;
import org.apache.beam.sdk.transforms.Flatten;
import org.apache.beam.sdk.transforms.MapElements;
import org.apache.beam.sdk.transforms.ParDo;
import org.apache.beam.sdk.transforms.Watch.Growth;
import org.apache.beam.sdk.values.PCollection;
import org.apache.beam.sdk.values.PCollectionList;
import org.apache.beam.sdk.values.PCollectionTuple;
import org.apache.beam.sdk.values.TupleTag;
import org.apache.beam.sdk.values.TupleTagList;
import org.apache.commons.lang3.StringUtils;
import org.joda.time.Duration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The {@link TextToBigQueryStreaming} is a streaming version of {@link TextIOToBigQuery} pipeline
 * that reads text files, applies a JavaScript UDF and writes the output to BigQuery. The pipeline
 * continuously polls for new files, reads them row-by-row and processes each record into BigQuery.
 * The polling interval is set at 10 seconds.
 *
 * <p>Check out <a
 * href="https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/main/v2/googlecloud-to-googlecloud/README_Stream_GCS_Text_to_BigQuery_Flex.md">README</a>
 * for instructions on how to use or modify this template.
 */
@MultiTemplate({
  @Template(
      name = "Stream_GCS_Text_to_BigQuery_Flex",
      category = TemplateCategory.STREAMING,
      displayName = "Cloud Storage Text to BigQuery (Stream)",
      description = {
        "The Text Files on Cloud Storage to BigQuery pipeline is a streaming pipeline that allows you to stream text files stored in Cloud Storage, transform them using a JavaScript User Defined Function (UDF) that you provide, and append the result to BigQuery.\n",
        "The pipeline runs indefinitely and needs to be terminated manually via a\n"
            + "    <a href=\"https://cloud.google.com/dataflow/docs/guides/stopping-a-pipeline#cancel\">cancel</a> and not a\n"
            + "    <a href=\"https://cloud.google.com/dataflow/docs/guides/stopping-a-pipeline#drain\">drain</a>, due to its use of the\n"
            + "    <code>Watch</code> transform, which is a splittable <code>DoFn</code> that does not support\n"
            + "    draining."
      },
      skipOptions = {
        "pythonExternalTextTransfromGcsPath",
        "pythonExternalTextTransformFunctionName"
      },
      optionsClass = TextToBigQueryStreamingOptions.class,
      flexContainerName = "text-to-bigquery-streaming",
      documentation =
          "https://cloud.google.com/dataflow/docs/guides/templates/provided/text-to-bigquery-stream",
      contactInformation = "https://cloud.google.com/support",
      requirements = {
        "Create a JSON file that describes the schema of your output table in BigQuery.\n"
            + "    <p>\n"
            + "      Ensure that there is a top-level JSON array titled <code>fields</code> and that its\n"
            + "      contents follow the pattern <code>{\"name\": \"COLUMN_NAME\", \"type\": \"DATA_TYPE\"}</code>.\n"
            + "      For example:\n"
            + "    </p>\n"
            + "<pre class=\"prettyprint lang-json\">\n"
            + "{\n"
            + "  \"fields\": [\n"
            + "    {\n"
            + "      \"name\": \"location\",\n"
            + "      \"type\": \"STRING\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"name\",\n"
            + "      \"type\": \"STRING\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"age\",\n"
            + "      \"type\": \"STRING\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"color\",\n"
            + "      \"type\": \"STRING\",\n"
            + "      \"mode\": \"REQUIRED\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"coffee\",\n"
            + "      \"type\": \"STRING\",\n"
            + "      \"mode\": \"REQUIRED\"\n"
            + "    }\n"
            + "  ]\n"
            + "}\n"
            + "</pre>",
        "Create a JavaScript (<code>.js</code>) file with your UDF function that supplies the logic\n"
            + "    to transform the lines of text. Note that your function must return a JSON string.\n"
            + "    <p>For example, this function splits each line of a CSV file and returns a JSON string after\n"
            + "      transforming the values.</p>\n"
            + "<pre class=\"prettyprint\" suppresswarning>\n"
            + "function transform(line) {\n"
            + "var values = line.split(',');\n"
            + "\n"
            + "var obj = new Object();\n"
            + "obj.location = values[0];\n"
            + "obj.name = values[1];\n"
            + "obj.age = values[2];\n"
            + "obj.color = values[3];\n"
            + "obj.coffee = values[4];\n"
            + "var jsonString = JSON.stringify(obj);\n"
            + "\n"
            + "return jsonString;\n"
            + "}\n"
            + "</pre>"
      },
      streaming = true,
      supportsAtLeastOnce = true),
  @Template(
      name = "Stream_GCS_Text_to_BigQuery_Xlang",
      category = TemplateCategory.STREAMING,
      displayName = "Cloud Storage Text to BigQuery (Stream) with Python UDF",
      type = Template.TemplateType.XLANG,
      description = {
        "The Text Files on Cloud Storage to BigQuery pipeline is a streaming pipeline that allows you to stream text files stored in Cloud Storage, transform them using a Python User Defined Function (UDF) that you provide, and append the result to BigQuery.\n",
        "The pipeline runs indefinitely and needs to be terminated manually via a\n"
            + "    <a href=\"https://cloud.google.com/dataflow/docs/guides/stopping-a-pipeline#cancel\">cancel</a> and not a\n"
            + "    <a href=\"https://cloud.google.com/dataflow/docs/guides/stopping-a-pipeline#drain\">drain</a>, due to its use of the\n"
            + "    <code>Watch</code> transform, which is a splittable <code>DoFn</code> that does not support\n"
            + "    draining."
      },
      skipOptions = {
        "javascriptTextTransformGcsPath",
        "javascriptTextTransformFunctionName",
        "javascriptTextTransformReloadIntervalMinutes"
      },
      optionsClass = TextToBigQueryStreamingOptions.class,
      flexContainerName = "text-to-bigquery-streaming-xlang",
      documentation =
          "https://cloud.google.com/dataflow/docs/guides/templates/provided/text-to-bigquery-stream",
      contactInformation = "https://cloud.google.com/support",
      requirements = {
        "Create a JSON file that describes the schema of your output table in BigQuery.\n"
            + "    <p>\n"
            + "      Ensure that there is a top-level JSON array titled <code>fields</code> and that its\n"
            + "      contents follow the pattern <code>{\"name\": \"COLUMN_NAME\", \"type\": \"DATA_TYPE\"}</code>.\n"
            + "      For example:\n"
            + "    </p>\n"
            + "<pre class=\"prettyprint lang-json\">\n"
            + "{\n"
            + "  \"fields\": [\n"
            + "    {\n"
            + "      \"name\": \"location\",\n"
            + "      \"type\": \"STRING\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"name\",\n"
            + "      \"type\": \"STRING\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"age\",\n"
            + "      \"type\": \"STRING\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"color\",\n"
            + "      \"type\": \"STRING\",\n"
            + "      \"mode\": \"REQUIRED\"\n"
            + "    },\n"
            + "    {\n"
            + "      \"name\": \"coffee\",\n"
            + "      \"type\": \"STRING\",\n"
            + "      \"mode\": \"REQUIRED\"\n"
            + "    }\n"
            + "  ]\n"
            + "}\n"
            + "</pre>",
        "Create a Python (<code>.js</code>) file with your UDF function that supplies the logic\n"
            + "    to transform the lines of text. Note that your function must return a JSON string.\n"
            + "    <p>For example, this function splits each line of a CSV file and returns a JSON string after\n"
            + "      transforming the values.</p>\n"
            + "<pre class=\"prettyprint\" suppresswarning>\n"
            + "import json\n"
            + "def transform(line): \n"
            + "  values = line.split(',')\n"
            + "\n"
            + "  obj = {\n"
            + "     'location' : values[0],\n"
            + "     'name' : values[1],\n"
            + "     'age' : values[2],\n"
            + "     'color' : values[3],\n"
            + "     'coffee' : values[4]\n"
            + "  }\n"
            + "  jsonString = JSON.dumps(obj);\n"
            + "\n"
            + "  return jsonString;\n"
            + "\n"
            + "</pre>"
      },
      streaming = true,
      supportsAtLeastOnce = true)
})
public class TextToBigQueryStreaming {

  private static final Logger LOG = LoggerFactory.getLogger(TextToBigQueryStreaming.class);

  /** The tag for the main output for the UDF. */
  private static final TupleTag<FailsafeElement<String, String>> UDF_OUT =
      new TupleTag<FailsafeElement<String, String>>() {};

  /** The tag for the dead-letter output of the udf. */
  private static final TupleTag<FailsafeElement<String, String>> UDF_DEADLETTER_OUT =
      new TupleTag<FailsafeElement<String, String>>() {};

  /** The tag for the main output of the json transformation. */
  private static final TupleTag<TableRow> TRANSFORM_OUT = new TupleTag<TableRow>() {};

  /** The tag for the dead-letter output of the json to table row transform. */
  private static final TupleTag<FailsafeElement<String, String>> TRANSFORM_DEADLETTER_OUT =
      new TupleTag<FailsafeElement<String, String>>() {};

  /** The default suffix for error tables if dead letter table is not specified. */
  private static final String DEFAULT_DEADLETTER_TABLE_SUFFIX = "_error_records";

  /** Default interval for polling files in GCS. */
  private static final Duration DEFAULT_POLL_INTERVAL = Duration.standardSeconds(10);

  /** Coder for FailsafeElement. */
  private static final FailsafeElementCoder<String, String> FAILSAFE_ELEMENT_CODER =
      FailsafeElementCoder.of(StringUtf8Coder.of(), StringUtf8Coder.of());

  private static final JsonFactory JSON_FACTORY = Transport.getJsonFactory();

  /**
   * Main entry point for executing the pipeline. This will run the pipeline asynchronously. If
   * blocking execution is required, use the {@link
   * TextToBigQueryStreaming#run(TextToBigQueryStreamingOptions)} method to start the pipeline and
   * invoke {@code result.waitUntilFinish()} on the {@link PipelineResult}
   *
   * @param args The command-line arguments to the pipeline.
   */
  public static void main(String[] args) {
    UncaughtExceptionLogger.register();

    // Parse the user options passed from the command-line
    TextToBigQueryStreamingOptions options =
        PipelineOptionsFactory.fromArgs(args)
            .withValidation()
            .as(TextToBigQueryStreamingOptions.class);
    BigQueryIOUtils.validateBQStorageApiOptionsStreaming(options);

    run(options);
  }

  /**
   * Runs the pipeline with the supplied options.
   *
   * @param options The execution parameters to the pipeline.
   * @return The result of the pipeline execution.
   */
  public static PipelineResult run(TextToBigQueryStreamingOptions options) {

    // Create the pipeline
    Pipeline pipeline = Pipeline.create(options);

    // Register the coder for pipeline
    FailsafeElementCoder<String, String> coder =
        FailsafeElementCoder.of(StringUtf8Coder.of(), StringUtf8Coder.of());

    CoderRegistry coderRegistry = pipeline.getCoderRegistry();
    coderRegistry.registerCoderForType(coder.getEncodedTypeDescriptor(), coder);

    // Determine if we are using Python UDFs or JS UDFs based on the provided options.
    boolean useJavascriptUdf = !Strings.isNullOrEmpty(options.getJavascriptTextTransformGcsPath());
    boolean usePythonUdf = !Strings.isNullOrEmpty(options.getPythonExternalTextTransformGcsPath());
    if (useJavascriptUdf && usePythonUdf) {
      throw new IllegalArgumentException(
          "Either javascript or Python gcs path must be provided, but not both.");
    }

    /*
     * Steps:
     *  1) Read from the text source continuously.
     *  2) Convert to FailsafeElement.
     *  3) Apply Javascript udf transformation.
     *    - Tag records that were successfully transformed and those
     *      that failed transformation.
     *  4) Convert records to TableRow.
     *    - Tag records that were successfully converted and those
     *      that failed conversion.
     *  5) Insert successfully converted records into BigQuery.
     *    - Errors encountered while streaming will be sent to deadletter table.
     *  6) Insert records that failed into deadletter table.
     */

    PCollection<String> sourceRead =
        pipeline.apply(
            TextIO.read()
                .from(options.getInputFilePattern())
                .watchForNewFiles(DEFAULT_POLL_INTERVAL, Growth.never()));
    PCollectionTuple transformedOutput;
    if (usePythonUdf) {
      transformedOutput =
          sourceRead
              .apply(
                  "MapToRecord",
                  PythonExternalTextTransformer.FailsafeRowPythonExternalUdf
                      .stringMappingFunction())
              .setRowSchema(PythonExternalTextTransformer.FailsafeRowPythonExternalUdf.ROW_SCHEMA)
              .apply(
                  "InvokeUDF",
                  PythonExternalTextTransformer.FailsafePythonExternalUdf.newBuilder()
                      .setFileSystemPath(options.getPythonExternalTextTransformGcsPath())
                      .setFunctionName(options.getPythonExternalTextTransformFunctionName())
                      .build())
              .apply(
                  ParDo.of(new RowToStringFailsafeElementFn(UDF_OUT, UDF_DEADLETTER_OUT))
                      .withOutputTags(UDF_OUT, TupleTagList.of(UDF_DEADLETTER_OUT)));

    } else {
      transformedOutput =
          pipeline

              // 1) Read from the text source continuously.
              .apply(
                  "ReadFromSource",
                  TextIO.read()
                      .from(options.getInputFilePattern())
                      .watchForNewFiles(DEFAULT_POLL_INTERVAL, Growth.never()))

              // 2) Convert to FailsafeElement.
              .apply(
                  "ConvertToFailsafeElement",
                  MapElements.into(FAILSAFE_ELEMENT_CODER.getEncodedTypeDescriptor())
                      .via(input -> FailsafeElement.of(input, input)))

              // 3) Apply Javascript udf transformation.
              .apply(
                  "ApplyUDFTransformation",
                  FailsafeJavascriptUdf.<String>newBuilder()
                      .setFileSystemPath(options.getJavascriptTextTransformGcsPath())
                      .setFunctionName(options.getJavascriptTextTransformFunctionName())
                      .setReloadIntervalMinutes(
                          options.getJavascriptTextTransformReloadIntervalMinutes())
                      .setSuccessTag(UDF_OUT)
                      .setFailureTag(UDF_DEADLETTER_OUT)
                      .build());
    }

    PCollectionTuple convertedTableRows =
        transformedOutput

            // 4) Convert records to TableRow.
            .get(UDF_OUT)
            .apply(
                "ConvertJSONToTableRow",
                FailsafeJsonToTableRow.<String>newBuilder()
                    .setSuccessTag(TRANSFORM_OUT)
                    .setFailureTag(TRANSFORM_DEADLETTER_OUT)
                    .build());

    WriteResult writeResult =
        convertedTableRows

            // 5) Insert successfully converted records into BigQuery.
            .get(TRANSFORM_OUT)
            .apply(
                "InsertIntoBigQuery",
                BigQueryIO.writeTableRows()
                    .withJsonSchema(GCSUtils.getGcsFileAsString(options.getJSONPath()))
                    .to(options.getOutputTable())
                    .withExtendedErrorInfo()
                    .withoutValidation()
                    .withCreateDisposition(CreateDisposition.CREATE_IF_NEEDED)
                    .withWriteDisposition(WriteDisposition.WRITE_APPEND)
                    .withFailedInsertRetryPolicy(InsertRetryPolicy.retryTransientErrors())
                    .withCustomGcsTempLocation(
                        StaticValueProvider.of(options.getBigQueryLoadingTemporaryDirectory())));

    // Elements that failed inserts into BigQuery are extracted and converted to FailsafeElement
    PCollection<FailsafeElement<String, String>> failedInserts =
        BigQueryIOUtils.writeResultToBigQueryInsertErrors(writeResult, options)
            .apply(
                "WrapInsertionErrors",
                MapElements.into(FAILSAFE_ELEMENT_CODER.getEncodedTypeDescriptor())
                    .via(TextToBigQueryStreaming::wrapBigQueryInsertError));

    // 6) Insert records that failed transformation or conversion into deadletter table
    PCollectionList.of(
            ImmutableList.of(
                transformedOutput.get(UDF_DEADLETTER_OUT),
                convertedTableRows.get(TRANSFORM_DEADLETTER_OUT),
                failedInserts))
        .apply("Flatten", Flatten.pCollections())
        .apply(
            "WriteFailedRecords",
            WriteStringMessageErrors.newBuilder()
                .setErrorRecordsTable(
                    StringUtils.isNotEmpty(options.getOutputDeadletterTable())
                        ? options.getOutputDeadletterTable()
                        : options.getOutputTable() + DEFAULT_DEADLETTER_TABLE_SUFFIX)
                .setErrorRecordsTableSchema(ResourceUtils.getDeadletterTableSchemaJson())
                .build());

    return pipeline.run();
  }

  /**
   * Method to wrap a {@link BigQueryInsertError} into a {@link FailsafeElement}.
   *
   * @param insertError BigQueryInsert error.
   * @return FailsafeElement object.
   * @throws IOException
   */
  static FailsafeElement<String, String> wrapBigQueryInsertError(BigQueryInsertError insertError) {

    FailsafeElement<String, String> failsafeElement;
    try {

      String rowPayload = JSON_FACTORY.toString(insertError.getRow());
      String errorMessage = JSON_FACTORY.toString(insertError.getError());

      failsafeElement = FailsafeElement.of(rowPayload, rowPayload);
      failsafeElement.setErrorMessage(errorMessage);

    } catch (IOException e) {
      throw new RuntimeException(e);
    }

    return failsafeElement;
  }

  /**
   * The {@link TextToBigQueryStreamingOptions} class provides the custom execution options passed
   * by the executor at the command-line.
   */
  public interface TextToBigQueryStreamingOptions
      extends TextIOToBigQuery.Options, BigQueryStorageApiStreamingOptions {
    @TemplateParameter.BigQueryTable(
        order = 1,
        optional = true,
        description = "The dead-letter table name to output failed messages to BigQuery",
        helpText =
            "Table for messages that failed to reach the output table. If a table doesn't exist, it is created during "
                + "pipeline execution. If not specified, `<outputTableSpec>_error_records` is used.",
        example = "<PROJECT_ID>:<DATASET_NAME>.<TABLE_NAME>")
    String getOutputDeadletterTable();

    void setOutputDeadletterTable(String value);

    // Hide the UseStorageWriteApiAtLeastOnce in the UI, because it will automatically be turned
    // on when pipeline is running on ALO mode and using the Storage Write API
    @TemplateParameter.Boolean(
        order = 2,
        optional = true,
        parentName = "useStorageWriteApi",
        parentTriggerValues = {"true"},
        description = "Use at at-least-once semantics in BigQuery Storage Write API",
        helpText =
            "This parameter takes effect only if `Use BigQuery Storage Write API` is enabled. If"
                + " enabled the at-least-once semantics will be used for Storage Write API, otherwise"
                + " exactly-once semantics will be used.",
        hiddenUi = true)
    @Default.Boolean(false)
    @Override
    Boolean getUseStorageWriteApiAtLeastOnce();

    void setUseStorageWriteApiAtLeastOnce(Boolean value);
  }
}

Passaggi successivi