Spanner to BigQuery template

Beta

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the Service Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see the launch stage descriptions.

The Spanner to BigQuery template is a batch pipeline that reads data from a Spanner table and writes the data to BigQuery.

Pipeline requirements

• The source Spanner table must exist prior to running the pipeline.
• The BigQuery dataset must exist prior to running the pipeline.
• A JSON file that describes your BigQuery schema.

  The file must contain a top-level JSON array titled fields. The contents of the fields array must use the following pattern:
  {"name": "COLUMN_NAME", "type": "DATA_TYPE"}.

  The following JSON describes an example BigQuery schema:

  {
    "fields": [
      {
        "name": "location",
        "type": "STRING"
      },
      {
        "name": "name",
        "type": "STRING"
      },
      {
        "name": "age",
        "type": "STRING"
      },
      {
        "name": "color",
        "type": "STRING"
      },
      {
        "name": "coffee",
        "type": "STRING"
      }
    ]
  }

  The Spanner to BigQuery batch template doesn't support importing data into STRUCT (Record) fields in the target BigQuery table.

Template parameters

Required parameters

• spannerInstanceId : The instance ID of the Spanner database to read from.
• spannerDatabaseId : The database ID of the Spanner database to export.
• outputTableSpec : The BigQuery output table location to write the output to. For example, <PROJECT_ID>:<DATASET_NAME>.<TABLE_NAME>.Depending on the createDisposition specified, the output table might be created automatically using the user provided Avro schema.

Optional parameters

• spannerProjectId : The ID of the project that the Spanner database resides in. The default value for this parameter is the project where the Dataflow pipeline is running.
• spannerTableId : The table name of the Spanner database to export. Ignored if sqlQuery is set.
• spannerRpcPriority : The request priority (https://cloud.google.com/spanner/docs/reference/rest/v1/RequestOptions) for Spanner calls. Possible values are HIGH, MEDIUM, and LOW. The default value is HIGH.
• sqlQuery : The SQL query to use to read data from the Spanner database. Required if spannerTableId is empty.
• bigQuerySchemaPath : The Cloud Storage path (gs://) to the JSON file that defines your BigQuery schema. (Example: gs://your-bucket/your-schema.json).
• writeDisposition : The BigQuery WriteDisposition (https://cloud.google.com/bigquery/docs/reference/rest/v2/Job#jobconfigurationload) value. For example, WRITE_APPEND, WRITE_EMPTY, or WRITE_TRUNCATE. Defaults to WRITE_APPEND.
• createDisposition : The BigQuery CreateDisposition (https://cloud.google.com/bigquery/docs/reference/rest/v2/Job#jobconfigurationload). For example, CREATE_IF_NEEDED and CREATE_NEVER. Defaults to CREATE_IF_NEEDED.
• useStorageWriteApi : If true, the pipeline uses the BigQuery Storage Write API (https://cloud.google.com/bigquery/docs/write-api). The default value is false. For more information, see Using the Storage Write API (https://beam.apache.org/documentation/io/built-in/google-bigquery/#storage-write-api).
• useStorageWriteApiAtLeastOnce : When using the Storage Write API, specifies the write semantics. To use at-least-once semantics (https://beam.apache.org/documentation/io/built-in/google-bigquery/#at-least-once-semantics), set this parameter to true. To use exactly-once semantics, set the parameter to false. This parameter applies only when useStorageWriteApi is true. The default value is false.

Run the template

Console

1. Go to the Dataflow Create job from template page.
Go to Create job from template
2. In the Job name field, enter a unique job name.
3. Optional: For Regional endpoint, select a value from the drop-down menu. The default region is us-central1.

   For a list of regions where you can run a Dataflow job, see Dataflow locations.

4. From the Dataflow template drop-down menu, select the Spanner to BigQuery template.
5. In the provided parameter fields, enter your parameter values.
6. Click Run job.

gcloud

Note: To use the Google Cloud CLI to run flex templates, you must have Google Cloud CLI version 284.0.0 or later.

In your shell or terminal, run the template:

gcloud dataflow flex-template run JOB_NAME \
    --template-file-gcs-location=gs://dataflow-templates-REGION_NAME/VERSION/flex/Cloud_Spanner_to_BigQuery_Flex \
    --project=PROJECT_ID \
    --region=REGION_NAME \
    --parameters \
       spannerInstanceId=SPANNER_INSTANCE_ID,\
       spannerDatabaseId=SPANNER_DATABASE_ID,\
       spannerTableId=SPANNER_TABLE_ID,\
       sqlQuery=SQL_QUERY,\
       outputTableSpec=OUTPUT_TABLE_SPEC,\

Replace the following:

• JOB_NAME: a unique job name of your choice
• VERSION: the version of the template that you want to use

  You can use the following values:

  • latest to use the latest version of the template, which is available in the non-dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/latest/
  • the version name, like 2023-09-12-00_RC00, to use a specific version of the template, which can be found nested in the respective dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/
  Caution: The latest version of templates might update with breaking changes. Your production environments should use templates kept in the most recent dated parent folder to prevent these breaking changes from affecting your production workflows.
• REGION_NAME: the region where you want to deploy your Dataflow job—for example, us-central1
• SPANNER_INSTANCE_ID: the Spanner instance ID
• SPANNER_DATABASE_ID: the Spanner database ID
• SPANNER_TABLE_ID: the Spanner table name
• SQL_QUERY: the SQL query
• OUTPUT_TABLE_SPEC: the BigQuery table location

API

To run the template using the REST API, send an HTTP POST request. For more information on the API and its authorization scopes, see projects.templates.launch.

POST https://dataflow.googleapis.com/v1b3/projects/PROJECT_ID/locations/LOCATION/flexTemplates:launch
{
   "launchParameter": {
     "jobName": "JOB_NAME",
     "parameters": {
       "spannerInstanceId": "SPANNER_INSTANCE_ID",
       "spannerDatabaseId": "SPANNER_DATABASE_ID",
       "spannerTableId": "SPANNER_TABLE_ID",
       "sqlQuery": "SQL_QUERY",
       "outputTableSpec": "OUTPUT_TABLE_SPEC",
     },
     "containerSpecGcsPath": "gs://dataflow-templates-LOCATION/VERSION/flex/Cloud_Spanner_to_BigQuery_Flex",
     "environment": { "maxWorkers": "10" }
  }
}

Replace the following:

• PROJECT_ID: the Google Cloud project ID where you want to run the Dataflow job
• JOB_NAME: a unique job name of your choice
• VERSION: the version of the template that you want to use

  You can use the following values:

  • latest to use the latest version of the template, which is available in the non-dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/latest/
  • the version name, like 2023-09-12-00_RC00, to use a specific version of the template, which can be found nested in the respective dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/
  Caution: The latest version of templates might update with breaking changes. Your production environments should use templates kept in the most recent dated parent folder to prevent these breaking changes from affecting your production workflows.
• LOCATION: the region where you want to deploy your Dataflow job—for example, us-central1
• SPANNER_INSTANCE_ID: the Spanner instance ID
• SPANNER_DATABASE_ID: the Spanner database ID
• SPANNER_TABLE_ID: the Spanner table name
• SQL_QUERY: the SQL query
• OUTPUT_TABLE_SPEC: the BigQuery table location

Template source code

Java

/*
 * Copyright (C) 2022 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 static com.google.cloud.teleport.v2.utils.GCSUtils.getGcsFileAsString;
import static org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO.Write.CreateDisposition.CREATE_NEVER;

import com.google.cloud.teleport.metadata.Template;
import com.google.cloud.teleport.metadata.TemplateCategory;
import com.google.cloud.teleport.v2.common.UncaughtExceptionLogger;
import com.google.cloud.teleport.v2.options.SpannerToBigQueryOptions;
import com.google.cloud.teleport.v2.transforms.BigQueryConverters;
import com.google.cloud.teleport.v2.transforms.SpannerToBigQueryTransform.StructToJson;
import com.google.cloud.teleport.v2.utils.BigQueryIOUtils;
import com.google.common.base.Strings;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO.Write;
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.spanner.SpannerConfig;
import org.apache.beam.sdk.io.gcp.spanner.SpannerIO;
import org.apache.beam.sdk.options.PipelineOptionsFactory;

/** Template to read data from a Spanner table and write into a BigQuery table. */
@Template(
    name = "Cloud_Spanner_to_BigQuery_Flex",
    category = TemplateCategory.BATCH,
    displayName = "Spanner to BigQuery",
    description =
        "The Spanner to BigQuery template is a batch pipeline that reads data from a Spanner table, and writes them to a BigQuery table.",
    optionsClass = SpannerToBigQueryOptions.class,
    flexContainerName = "spanner-to-bigquery",
    documentation =
        "https://cloud.google.com/dataflow/docs/guides/templates/provided/spanner-to-bigquery",
    contactInformation = "https://cloud.google.com/support")
public final class SpannerToBigQuery {

  public static void main(String[] args) {
    UncaughtExceptionLogger.register();

    PipelineOptionsFactory.register(SpannerToBigQueryOptions.class);
    SpannerToBigQueryOptions options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(SpannerToBigQueryOptions.class);

    BigQueryIOUtils.validateBQStorageApiOptionsBatch(options);

    Pipeline pipeline = Pipeline.create(options);

    SpannerConfig spannerConfig =
        SpannerConfig.create()
            .withProjectId(
                options.getSpannerProjectId().isEmpty()
                    ? options.getProject()
                    : options.getSpannerProjectId())
            .withDatabaseId(options.getSpannerDatabaseId())
            .withInstanceId(options.getSpannerInstanceId())
            .withRpcPriority(options.getSpannerRpcPriority());

    SpannerIO.Read read = SpannerIO.read().withSpannerConfig(spannerConfig);

    if (!Strings.isNullOrEmpty(options.getSqlQuery())) {
      read = read.withQuery(options.getSqlQuery());
    } else if (!Strings.isNullOrEmpty(options.getSpannerTableId())) {
      read = read.withTable(options.getSpannerTableId());
    } else {
      throw new IllegalArgumentException("either sqlQuery or spannerTableId required");
    }
    pipeline
        .apply(read)
        .apply(new StructToJson())
        .apply("Write To BigQuery", writeToBigQuery(options));

    pipeline.run();
  }

  private static Write<String> writeToBigQuery(SpannerToBigQueryOptions options) {
    if (CreateDisposition.valueOf(options.getCreateDisposition()) == CREATE_NEVER) {
      return BigQueryIO.<String>write()
          .to(options.getOutputTableSpec())
          .withWriteDisposition(WriteDisposition.valueOf(options.getWriteDisposition()))
          .withCreateDisposition(CreateDisposition.valueOf(options.getCreateDisposition()))
          .withExtendedErrorInfo()
          .withFormatFunction(BigQueryConverters::convertJsonToTableRow);
    }
    return BigQueryIO.<String>write()
        .to(options.getOutputTableSpec())
        .withWriteDisposition(WriteDisposition.valueOf(options.getWriteDisposition()))
        .withCreateDisposition(CreateDisposition.valueOf(options.getCreateDisposition()))
        .withExtendedErrorInfo()
        .withFormatFunction(BigQueryConverters::convertJsonToTableRow)
        .withJsonSchema(getGcsFileAsString(options.getBigQuerySchemaPath()));
  }
}

What's next

• Learn about Dataflow templates.
• See the list of Google-provided templates.