Eseguire lo streaming dei dati utilizzando l'API Storage Write

Questo documento descrive come utilizzare l'API BigQuery Storage Write per inserire flussi di dati in BigQuery.

Negli scenari di streaming, i dati arrivano continuamente e dovrebbero essere disponibili per le letture con latenza minima. Quando utilizzi l'API BigQuery Storage Write per i carichi di lavoro streaming, valuta le garanzie di cui hai bisogno:

• Se la tua applicazione ha bisogno solo di semantica almeno una volta, utilizza il metodo predefinito streaming.
• Se hai bisogno di semantica "exactly-once", crea uno o più flussi in confermato e usare gli offset di flusso per garantire le scritture "exactly-once".

Nel tipo di commit, i dati scritti nello stream sono disponibili per le query non appena il server conferma la richiesta di scrittura. Lo stream predefinito utilizza anche ma non fornisce garanzie "exactly-once".

Utilizza il flusso predefinito per la semantica "at-least-once"

Se la tua applicazione può accettare la possibilità che nella tabella di destinazione vengano visualizzati record duplicati, ti consigliamo di utilizzare lo stream predefinito per gli scenari di streaming.

Il codice seguente mostra come scrivere dati nel flusso predefinito:

Java

Per scoprire come installare e utilizzare la libreria client per BigQuery, consulta Librerie client di BigQuery. Per ulteriori informazioni, consulta la documentazione di riferimento dell'API BigQuery Java.

Per eseguire l'autenticazione su BigQuery, configura Credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per le librerie client.

import com.google.api.core.ApiFuture;
import com.google.api.core.ApiFutureCallback;
import com.google.api.core.ApiFutures;
import com.google.api.gax.core.FixedExecutorProvider;
import com.google.api.gax.retrying.RetrySettings;
import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.QueryJobConfiguration;
import com.google.cloud.bigquery.TableResult;
import com.google.cloud.bigquery.storage.v1.AppendRowsRequest;
import com.google.cloud.bigquery.storage.v1.AppendRowsResponse;
import com.google.cloud.bigquery.storage.v1.BigQueryWriteClient;
import com.google.cloud.bigquery.storage.v1.BigQueryWriteSettings;
import com.google.cloud.bigquery.storage.v1.Exceptions;
import com.google.cloud.bigquery.storage.v1.Exceptions.AppendSerializationError;
import com.google.cloud.bigquery.storage.v1.Exceptions.MaximumRequestCallbackWaitTimeExceededException;
import com.google.cloud.bigquery.storage.v1.Exceptions.StorageException;
import com.google.cloud.bigquery.storage.v1.Exceptions.StreamWriterClosedException;
import com.google.cloud.bigquery.storage.v1.JsonStreamWriter;
import com.google.cloud.bigquery.storage.v1.TableName;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.protobuf.ByteString;
import com.google.protobuf.Descriptors.DescriptorValidationException;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.Phaser;
import java.util.concurrent.atomic.AtomicInteger;
import javax.annotation.concurrent.GuardedBy;
import org.json.JSONArray;
import org.json.JSONObject;
import org.threeten.bp.Duration;

public class WriteToDefaultStream {

  public static void runWriteToDefaultStream()
      throws DescriptorValidationException, InterruptedException, IOException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "MY_PROJECT_ID";
    String datasetName = "MY_DATASET_NAME";
    String tableName = "MY_TABLE_NAME";
    writeToDefaultStream(projectId, datasetName, tableName);
  }

  private static ByteString buildByteString() {
    byte[] bytes = new byte[] {1, 2, 3, 4, 5};
    return ByteString.copyFrom(bytes);
  }

  // Create a JSON object that is compatible with the table schema.
  private static JSONObject buildRecord(int i, int j) {
    JSONObject record = new JSONObject();
    StringBuilder sbSuffix = new StringBuilder();
    for (int k = 0; k < j; k++) {
      sbSuffix.append(k);
    }
    record.put("test_string", String.format("record %03d-%03d %s", i, j, sbSuffix.toString()));
    ByteString byteString = buildByteString();
    record.put("test_bytes", byteString);
    record.put(
        "test_geo",
        "POLYGON((-124.49 47.35,-124.49 40.73,-116.49 40.73,-116.49 47.35,-124.49 47.35))");
    return record;
  }

  public static void writeToDefaultStream(String projectId, String datasetName, String tableName)
      throws DescriptorValidationException, InterruptedException, IOException {
    TableName parentTable = TableName.of(projectId, datasetName, tableName);

    DataWriter writer = new DataWriter();
    // One time initialization for the worker.
    writer.initialize(parentTable);

    // Write two batches of fake data to the stream, each with 10 JSON records.  Data may be
    // batched up to the maximum request size:
    // https://cloud.google.com/bigquery/quotas#write-api-limits
    for (int i = 0; i < 2; i++) {
      JSONArray jsonArr = new JSONArray();
      for (int j = 0; j < 10; j++) {
        JSONObject record = buildRecord(i, j);
        jsonArr.put(record);
      }

      writer.append(new AppendContext(jsonArr));
    }

    // Final cleanup for the stream during worker teardown.
    writer.cleanup();
    verifyExpectedRowCount(parentTable, 12);
    System.out.println("Appended records successfully.");
  }

  private static void verifyExpectedRowCount(TableName parentTable, int expectedRowCount)
      throws InterruptedException {
    String queryRowCount =
        "SELECT COUNT(*) FROM `"
            + parentTable.getProject()
            + "."
            + parentTable.getDataset()
            + "."
            + parentTable.getTable()
            + "`";
    QueryJobConfiguration queryConfig = QueryJobConfiguration.newBuilder(queryRowCount).build();
    BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();
    TableResult results = bigquery.query(queryConfig);
    int countRowsActual =
        Integer.parseInt(results.getValues().iterator().next().get("f0_").getStringValue());
    if (countRowsActual != expectedRowCount) {
      throw new RuntimeException(
          "Unexpected row count. Expected: " + expectedRowCount + ". Actual: " + countRowsActual);
    }
  }

  private static class AppendContext {

    JSONArray data;

    AppendContext(JSONArray data) {
      this.data = data;
    }
  }

  private static class DataWriter {

    private static final int MAX_RECREATE_COUNT = 3;

    private BigQueryWriteClient client;

    // Track the number of in-flight requests to wait for all responses before shutting down.
    private final Phaser inflightRequestCount = new Phaser(1);
    private final Object lock = new Object();
    private JsonStreamWriter streamWriter;

    @GuardedBy("lock")
    private RuntimeException error = null;

    private AtomicInteger recreateCount = new AtomicInteger(0);

    private JsonStreamWriter createStreamWriter(String tableName)
        throws DescriptorValidationException, IOException, InterruptedException {
      // Configure in-stream automatic retry settings.
      // Error codes that are immediately retried:
      // * ABORTED, UNAVAILABLE, CANCELLED, INTERNAL, DEADLINE_EXCEEDED
      // Error codes that are retried with exponential backoff:
      // * RESOURCE_EXHAUSTED
      RetrySettings retrySettings =
          RetrySettings.newBuilder()
              .setInitialRetryDelay(Duration.ofMillis(500))
              .setRetryDelayMultiplier(1.1)
              .setMaxAttempts(5)
              .setMaxRetryDelay(Duration.ofMinutes(1))
              .build();

      // Use the JSON stream writer to send records in JSON format. Specify the table name to write
      // to the default stream.
      // For more information about JsonStreamWriter, see:
      // https://googleapis.dev/java/google-cloud-bigquerystorage/latest/com/google/cloud/bigquery/storage/v1/JsonStreamWriter.html
      return JsonStreamWriter.newBuilder(tableName, client)
          .setExecutorProvider(FixedExecutorProvider.create(Executors.newScheduledThreadPool(100)))
          .setChannelProvider(
              BigQueryWriteSettings.defaultGrpcTransportProviderBuilder()
                  .setKeepAliveTime(org.threeten.bp.Duration.ofMinutes(1))
                  .setKeepAliveTimeout(org.threeten.bp.Duration.ofMinutes(1))
                  .setKeepAliveWithoutCalls(true)
                  .setChannelsPerCpu(2)
                  .build())
          .setEnableConnectionPool(true)
          // If value is missing in json and there is a default value configured on bigquery
          // column, apply the default value to the missing value field.
          .setDefaultMissingValueInterpretation(
              AppendRowsRequest.MissingValueInterpretation.DEFAULT_VALUE)
          .setRetrySettings(retrySettings)
          .build();
    }

    public void initialize(TableName parentTable)
        throws DescriptorValidationException, IOException, InterruptedException {
      // Initialize client without settings, internally within stream writer a new client will be
      // created with full settings.
      client = BigQueryWriteClient.create();

      streamWriter = createStreamWriter(parentTable.toString());
    }

    public void append(AppendContext appendContext)
        throws DescriptorValidationException, IOException, InterruptedException {
      synchronized (this.lock) {
        if (!streamWriter.isUserClosed()
            && streamWriter.isClosed()
            && recreateCount.getAndIncrement() < MAX_RECREATE_COUNT) {
          streamWriter = createStreamWriter(streamWriter.getStreamName());
          this.error = null;
        }
        // If earlier appends have failed, we need to reset before continuing.
        if (this.error != null) {
          throw this.error;
        }
      }
      // Append asynchronously for increased throughput.
      ApiFuture<AppendRowsResponse> future = streamWriter.append(appendContext.data);
      ApiFutures.addCallback(
          future, new AppendCompleteCallback(this, appendContext), MoreExecutors.directExecutor());

      // Increase the count of in-flight requests.
      inflightRequestCount.register();
    }

    public void cleanup() {
      // Wait for all in-flight requests to complete.
      inflightRequestCount.arriveAndAwaitAdvance();

      client.close();
      // Close the connection to the server.
      streamWriter.close();

      // Verify that no error occurred in the stream.
      synchronized (this.lock) {
        if (this.error != null) {
          throw this.error;
        }
      }
    }

    static class AppendCompleteCallback implements ApiFutureCallback<AppendRowsResponse> {

      private final DataWriter parent;
      private final AppendContext appendContext;

      public AppendCompleteCallback(DataWriter parent, AppendContext appendContext) {
        this.parent = parent;
        this.appendContext = appendContext;
      }

      public void onSuccess(AppendRowsResponse response) {
        System.out.format("Append success\n");
        this.parent.recreateCount.set(0);
        done();
      }

      public void onFailure(Throwable throwable) {
        if (throwable instanceof AppendSerializationError) {
          AppendSerializationError ase = (AppendSerializationError) throwable;
          Map<Integer, String> rowIndexToErrorMessage = ase.getRowIndexToErrorMessage();
          if (rowIndexToErrorMessage.size() > 0) {
            // Omit the faulty rows
            JSONArray dataNew = new JSONArray();
            for (int i = 0; i < appendContext.data.length(); i++) {
              if (!rowIndexToErrorMessage.containsKey(i)) {
                dataNew.put(appendContext.data.get(i));
              } else {
                // process faulty rows by placing them on a dead-letter-queue, for instance
              }
            }

            // Retry the remaining valid rows, but using a separate thread to
            // avoid potentially blocking while we are in a callback.
            if (dataNew.length() > 0) {
              try {
                this.parent.append(new AppendContext(dataNew));
              } catch (DescriptorValidationException e) {
                throw new RuntimeException(e);
              } catch (IOException e) {
                throw new RuntimeException(e);
              } catch (InterruptedException e) {
                throw new RuntimeException(e);
              }
            }
            // Mark the existing attempt as done since we got a response for it
            done();
            return;
          }
        }

        boolean resendRequest = false;
        if (throwable instanceof MaximumRequestCallbackWaitTimeExceededException) {
          resendRequest = true;
        } else if (throwable instanceof StreamWriterClosedException) {
          if (!parent.streamWriter.isUserClosed()) {
            resendRequest = true;
          }
        }
        if (resendRequest) {
          // Retry this request.
          try {
            this.parent.append(new AppendContext(appendContext.data));
          } catch (DescriptorValidationException e) {
            throw new RuntimeException(e);
          } catch (IOException e) {
            throw new RuntimeException(e);
          } catch (InterruptedException e) {
            throw new RuntimeException(e);
          }
          // Mark the existing attempt as done since we got a response for it
          done();
          return;
        }

        synchronized (this.parent.lock) {
          if (this.parent.error == null) {
            StorageException storageException = Exceptions.toStorageException(throwable);
            this.parent.error =
                (storageException != null) ? storageException : new RuntimeException(throwable);
          }
        }
        done();
      }

      private void done() {
        // Reduce the count of in-flight requests.
        this.parent.inflightRequestCount.arriveAndDeregister();
      }
    }
  }
}

Node.js

Per scoprire come installare e utilizzare la libreria client per BigQuery, consulta Librerie client di BigQuery.

Per eseguire l'autenticazione su BigQuery, configura Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client.

const {adapt, managedwriter} = require('@google-cloud/bigquery-storage');
const {WriterClient, JSONWriter} = managedwriter;

async function appendJSONRowsDefaultStream() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // projectId = 'my_project';
  // datasetId = 'my_dataset';
  // tableId = 'my_table';

  const destinationTable = `projects/${projectId}/datasets/${datasetId}/tables/${tableId}`;
  const writeClient = new WriterClient({projectId});

  try {
    const writeStream = await writeClient.getWriteStream({
      streamId: `${destinationTable}/streams/_default`,
      view: 'FULL',
    });
    const protoDescriptor = adapt.convertStorageSchemaToProto2Descriptor(
      writeStream.tableSchema,
      'root'
    );

    const connection = await writeClient.createStreamConnection({
      streamId: managedwriter.DefaultStream,
      destinationTable,
    });
    const streamId = connection.getStreamId();

    const writer = new JSONWriter({
      streamId,
      connection,
      protoDescriptor,
    });

    let rows = [];
    const pendingWrites = [];

    // Row 1
    let row = {
      row_num: 1,
      customer_name: 'Octavia',
    };
    rows.push(row);

    // Row 2
    row = {
      row_num: 2,
      customer_name: 'Turing',
    };
    rows.push(row);

    // Send batch.
    let pw = writer.appendRows(rows);
    pendingWrites.push(pw);

    rows = [];

    // Row 3
    row = {
      row_num: 3,
      customer_name: 'Bell',
    };
    rows.push(row);

    // Send batch.
    pw = writer.appendRows(rows);
    pendingWrites.push(pw);

    const results = await Promise.all(
      pendingWrites.map(pw => pw.getResult())
    );
    console.log('Write results:', results);
  } catch (err) {
    console.log(err);
  } finally {
    writeClient.close();
  }
}

Utilizzare il multiplexing

Attiva multiplexing a livello dell'autore dello stream solo per lo stream predefinito. Per attivare il multiplexing in Java, chiama il metodo setEnableConnectionPool quando crei un Oggetto StreamWriter o JsonStreamWriter:

// One possible way for constructing StreamWriter
StreamWriter.newBuilder(streamName)
              .setWriterSchema(protoSchema)
              .setEnableConnectionPool(true)
              .build();
// One possible way for constructing JsonStreamWriter
JsonStreamWriter.newBuilder(tableName, bigqueryClient)
              .setEnableConnectionPool(true)
              .build();

Per attivare il multiplexing in Go, consulta Condivisione della connessione (multiplexing).

Utilizza il tipo di commit per la semantica esattamente una volta

Se hai bisogno di semantica della scrittura "exactly-once", crea un flusso di scrittura nel commit di testo. Con il tipo di commit, i record sono disponibili per la query non appena il client riceve conferma dal backend.

Il tipo impegnato fornisce la pubblicazione "exactly-once" all'interno di uno stream mediante l'uso di degli offset record. Utilizzando gli offset di record, l'applicazione specifica aggiungere l'offset in ogni chiamata a AppendRows. L'operazione di scrittura viene eseguita solo se il valore dell'offset corrisponde all'offset di accodamento successivo. Per maggiori informazioni le informazioni, vedi Gestisci gli offset dei flussi per ottenere una semantica "exactly-once".

Se non fornisci un offset, i record vengono aggiunti alla fine corrente dello stream. In questo caso, se una richiesta di aggiunta restituisce un errore, riprova il record potrebbe apparire più volte nello stream.

Per utilizzare il tipo di commit, segui questi passaggi:

Java

1. Richiama CreateWriteStream per creare uno o più stream di tipo sottoposto a commit.
2. Per ogni stream, chiama AppendRows in un ciclo per scrivere batch di record.
3. Chiama FinalizeWriteStream per ogni stream per rilasciare lo stream. Dopo non puoi scrivere altre righe nel flusso. Questo passaggio è facoltativo nel tipo di commit, ma aiuta a evitare di superare il limite di stream attivi. Per ulteriori informazioni, consulta Limitare la frequenza di creazione degli stream.

Node.js

1. Chiama createWriteStreamFullResponse per creare uno o più stream nel tipo di commit.
2. Per ogni stream, chiama appendRows in un ciclo per scrivere batch di record.
3. Chiama finalize per ogni stream per rilasciarlo. Dopo non puoi scrivere altre righe nel flusso. Questo passaggio è facoltativo nel tipo di commit, ma aiuta a evitare di superare il limite di stream attivi. Per ulteriori informazioni, vedi Limita la frequenza di creazione dello stream.

Non puoi eliminare uno stream in modo esplicito. Gli stream seguono la durata (TTL) definita dal sistema:

• Uno stream impegnato ha un TTL di tre giorni se non c'è traffico sullo stream.
• Per impostazione predefinita, uno stream con buffer ha un TTL di sette giorni se non c'è traffico nello stream.

Il codice seguente mostra come utilizzare il tipo di commit:

Java

Per scoprire come installare e utilizzare la libreria client per BigQuery, consulta Librerie client di BigQuery. Per ulteriori informazioni, consulta la documentazione di riferimento dell'API BigQuery Java.

Per eseguire l'autenticazione su BigQuery, configura Credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per le librerie client.

import com.google.api.core.ApiFuture;
import com.google.api.core.ApiFutureCallback;
import com.google.api.core.ApiFutures;
import com.google.api.gax.retrying.RetrySettings;
import com.google.cloud.bigquery.storage.v1.AppendRowsResponse;
import com.google.cloud.bigquery.storage.v1.BigQueryWriteClient;
import com.google.cloud.bigquery.storage.v1.CreateWriteStreamRequest;
import com.google.cloud.bigquery.storage.v1.Exceptions;
import com.google.cloud.bigquery.storage.v1.Exceptions.StorageException;
import com.google.cloud.bigquery.storage.v1.FinalizeWriteStreamResponse;
import com.google.cloud.bigquery.storage.v1.JsonStreamWriter;
import com.google.cloud.bigquery.storage.v1.TableName;
import com.google.cloud.bigquery.storage.v1.WriteStream;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.protobuf.Descriptors.DescriptorValidationException;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Phaser;
import javax.annotation.concurrent.GuardedBy;
import org.json.JSONArray;
import org.json.JSONObject;
import org.threeten.bp.Duration;

public class WriteCommittedStream {

  public static void runWriteCommittedStream()
      throws DescriptorValidationException, InterruptedException, IOException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "MY_PROJECT_ID";
    String datasetName = "MY_DATASET_NAME";
    String tableName = "MY_TABLE_NAME";

    writeCommittedStream(projectId, datasetName, tableName);
  }

  public static void writeCommittedStream(String projectId, String datasetName, String tableName)
      throws DescriptorValidationException, InterruptedException, IOException {
    BigQueryWriteClient client = BigQueryWriteClient.create();
    TableName parentTable = TableName.of(projectId, datasetName, tableName);

    DataWriter writer = new DataWriter();
    // One time initialization.
    writer.initialize(parentTable, client);

    try {
      // Write two batches of fake data to the stream, each with 10 JSON records.  Data may be
      // batched up to the maximum request size:
      // https://cloud.google.com/bigquery/quotas#write-api-limits
      long offset = 0;
      for (int i = 0; i < 2; i++) {
        // Create a JSON object that is compatible with the table schema.
        JSONArray jsonArr = new JSONArray();
        for (int j = 0; j < 10; j++) {
          JSONObject record = new JSONObject();
          record.put("col1", String.format("batch-record %03d-%03d", i, j));
          jsonArr.put(record);
        }
        writer.append(jsonArr, offset);
        offset += jsonArr.length();
      }
    } catch (ExecutionException e) {
      // If the wrapped exception is a StatusRuntimeException, check the state of the operation.
      // If the state is INTERNAL, CANCELLED, or ABORTED, you can retry. For more information, see:
      // https://grpc.github.io/grpc-java/javadoc/io/grpc/StatusRuntimeException.html
      System.out.println("Failed to append records. \n" + e);
    }

    // Final cleanup for the stream.
    writer.cleanup(client);
    System.out.println("Appended records successfully.");
  }

  // A simple wrapper object showing how the stateful stream writer should be used.
  private static class DataWriter {

    private JsonStreamWriter streamWriter;
    // Track the number of in-flight requests to wait for all responses before shutting down.
    private final Phaser inflightRequestCount = new Phaser(1);

    private final Object lock = new Object();

    @GuardedBy("lock")
    private RuntimeException error = null;

    void initialize(TableName parentTable, BigQueryWriteClient client)
        throws IOException, DescriptorValidationException, InterruptedException {
      // Initialize a write stream for the specified table.
      // For more information on WriteStream.Type, see:
      // https://googleapis.dev/java/google-cloud-bigquerystorage/latest/com/google/cloud/bigquery/storage/v1/WriteStream.Type.html
      WriteStream stream = WriteStream.newBuilder().setType(WriteStream.Type.COMMITTED).build();

      CreateWriteStreamRequest createWriteStreamRequest =
          CreateWriteStreamRequest.newBuilder()
              .setParent(parentTable.toString())
              .setWriteStream(stream)
              .build();
      WriteStream writeStream = client.createWriteStream(createWriteStreamRequest);

      // Configure in-stream automatic retry settings.
      // Error codes that are immediately retried:
      // * ABORTED, UNAVAILABLE, CANCELLED, INTERNAL, DEADLINE_EXCEEDED
      // Error codes that are retried with exponential backoff:
      // * RESOURCE_EXHAUSTED
      RetrySettings retrySettings =
          RetrySettings.newBuilder()
              .setInitialRetryDelay(Duration.ofMillis(500))
              .setRetryDelayMultiplier(1.1)
              .setMaxAttempts(5)
              .setMaxRetryDelay(Duration.ofMinutes(1))
              .build();

      // Use the JSON stream writer to send records in JSON format.
      // For more information about JsonStreamWriter, see:
      // https://googleapis.dev/java/google-cloud-bigquerystorage/latest/com/google/cloud/bigquery/storage/v1/JsonStreamWriter.html
      streamWriter =
          JsonStreamWriter.newBuilder(writeStream.getName(), writeStream.getTableSchema(), client)
              .setRetrySettings(retrySettings)
              .build();
    }

    public void append(JSONArray data, long offset)
        throws DescriptorValidationException, IOException, ExecutionException {
      synchronized (this.lock) {
        // If earlier appends have failed, we need to reset before continuing.
        if (this.error != null) {
          throw this.error;
        }
      }
      // Append asynchronously for increased throughput.
      ApiFuture<AppendRowsResponse> future = streamWriter.append(data, offset);
      ApiFutures.addCallback(
          future, new DataWriter.AppendCompleteCallback(this), MoreExecutors.directExecutor());
      // Increase the count of in-flight requests.
      inflightRequestCount.register();
    }

    public void cleanup(BigQueryWriteClient client) {
      // Wait for all in-flight requests to complete.
      inflightRequestCount.arriveAndAwaitAdvance();

      // Close the connection to the server.
      streamWriter.close();

      // Verify that no error occurred in the stream.
      synchronized (this.lock) {
        if (this.error != null) {
          throw this.error;
        }
      }

      // Finalize the stream.
      FinalizeWriteStreamResponse finalizeResponse =
          client.finalizeWriteStream(streamWriter.getStreamName());
      System.out.println("Rows written: " + finalizeResponse.getRowCount());
    }

    public String getStreamName() {
      return streamWriter.getStreamName();
    }

    static class AppendCompleteCallback implements ApiFutureCallback<AppendRowsResponse> {

      private final DataWriter parent;

      public AppendCompleteCallback(DataWriter parent) {
        this.parent = parent;
      }

      public void onSuccess(AppendRowsResponse response) {
        System.out.format("Append %d success\n", response.getAppendResult().getOffset().getValue());
        done();
      }

      public void onFailure(Throwable throwable) {
        synchronized (this.parent.lock) {
          if (this.parent.error == null) {
            StorageException storageException = Exceptions.toStorageException(throwable);
            this.parent.error =
                (storageException != null) ? storageException : new RuntimeException(throwable);
          }
        }
        System.out.format("Error: %s\n", throwable.toString());
        done();
      }

      private void done() {
        // Reduce the count of in-flight requests.
        this.parent.inflightRequestCount.arriveAndDeregister();
      }
    }
  }
}

Node.js

Per scoprire come installare e utilizzare la libreria client per BigQuery, consulta Librerie client di BigQuery.

Per eseguire l'autenticazione su BigQuery, configura Credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per le librerie client.

const {adapt, managedwriter} = require('@google-cloud/bigquery-storage');
const {WriterClient, JSONWriter} = managedwriter;

async function appendJSONRowsCommittedStream() {
  /**
   * TODO(developer): Uncomment the following lines before running the sample.
   */
  // projectId = 'my_project';
  // datasetId = 'my_dataset';
  // tableId = 'my_table';

  const destinationTable = `projects/${projectId}/datasets/${datasetId}/tables/${tableId}`;
  const streamType = managedwriter.CommittedStream;
  const writeClient = new WriterClient({projectId});

  try {
    const writeStream = await writeClient.createWriteStreamFullResponse({
      streamType,
      destinationTable,
    });
    const streamId = writeStream.name;
    console.log(`Stream created: ${streamId}`);

    const protoDescriptor = adapt.convertStorageSchemaToProto2Descriptor(
      writeStream.tableSchema,
      'root'
    );

    const connection = await writeClient.createStreamConnection({
      streamId,
    });

    const writer = new JSONWriter({
      streamId,
      connection,
      protoDescriptor,
    });

    let rows = [];
    const pendingWrites = [];

    // Row 1
    let row = {
      row_num: 1,
      customer_name: 'Octavia',
    };
    rows.push(row);

    // Row 2
    row = {
      row_num: 2,
      customer_name: 'Turing',
    };
    rows.push(row);

    // Send batch.
    let pw = writer.appendRows(rows);
    pendingWrites.push(pw);

    rows = [];

    // Row 3
    row = {
      row_num: 3,
      customer_name: 'Bell',
    };
    rows.push(row);

    // Send batch.
    pw = writer.appendRows(rows);
    pendingWrites.push(pw);

    const results = await Promise.all(
      pendingWrites.map(pw => pw.getResult())
    );
    console.log('Write results:', results);

    const {rowCount} = await connection.finalize();
    console.log(`Row count: ${rowCount}`);
  } catch (err) {
    console.log(err);
  } finally {
    writeClient.close();
  }
}