Sourcedb to Spanner 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 SourceDB to Spanner template is a batch pipeline that copies data from a relational database into an existing Spanner database. This pipeline uses JDBC to connect to the relational database. You can use this template to copy data from any relational database with available JDBC drivers into Spanner. This only supports a limited set of types of MySQL

For an extra layer of protection, you can also pass in a Cloud KMS key along with a Base64-encoded username, password, and connection string parameters encrypted with the Cloud KMS key. See the Cloud KMS API encryption endpoint for additional details on encrypting your username, password, and connection string parameters.

Pipeline requirements

• The JDBC drivers for the relational database must be available.
• The Spanner tables must exist before pipeline execution.
• The Spanner tables must have a compatible schema.
• The relational database must be accessible from the subnet where Dataflow runs.

Template parameters

Parameter	Description
sourceConfigURL	The JDBC connection URL string. For example, jdbc:mysql://127.4.5.30:3306/my-db?autoReconnect=true&maxReconnects=10&unicode=true&characterEncoding=UTF-8 or the shard config.
instanceId	The destination Cloud Spanner instance.
databaseId	The destination Cloud Spanner database.
projectId	This is the name of the Cloud Spanner project.
outputDirectory	This directory is used to dump the failed/skipped/filtered records in a migration.
jdbcDriverJars	Optional: The comma-separated list of driver JAR files. For example: gs://your-bucket/driver_jar1.jar,gs://your-bucket/driver_jar2.jar. Defaults to empty.
jdbcDriverClassName	Optional: The JDBC driver class name. For example: com.mysql.jdbc.Driver. Defaults to: com.mysql.jdbc.Driver.
username	Optional: The username to be used for the JDBC connection. Defaults to empty.
password	Optional: The password to be used for the JDBC connection. Defaults to empty.
tables	Optional: Tables to migrate from source. Defaults to empty.
numPartitions	Optional: The number of partitions. This, along with the lower and upper bound, form partitions strides for generated WHERE clause expressions used to split the partition column evenly. When the input is less than 1, the number is set to 1. Defaults to: 0.
spannerHost	Optional: The Cloud Spanner endpoint to call in the template. For example: https://batch-spanner.googleapis.com. Defaults to: https://batch-spanner.googleapis.com.
maxConnections	Optional: Configures the JDBC connection pool on each worker with maximum number of connections. Use a negative number for no limit. For example: -1. Defaults to: 0.
sessionFilePath	Optional: Session path in Cloud Storage that contains mapping information from Spanner Migration Tool. Defaults to empty.
transformationJarPath	Optional: Custom jar location in Cloud Storage that contains the custom transformation logic for processing records. Defaults to empty.
transformationClassName	Optional: Fully qualified class name having the custom transformation logic. It is a mandatory field in case transformationJarPath is specified. Defaults to empty.
transformationCustomParameters	Optional: String containing any custom parameters to be passed to the custom transformation class. Defaults to empty.
disabledAlgorithms	Optional: Comma separated algorithms to disable. If this value is set to none, no algorithm is disabled. Use this parameter with caution, because the algorithms disabled by default might have vulnerabilities or performance issues. For example: SSLv3, RC4.
extraFilesToStage	Optional: Comma separated Cloud Storage paths or Secret Manager secrets for files to stage in the worker. These files are saved in the /extra_files directory in each worker. For example: gs://<BUCKET>/file.txt,projects/<PROJECT_ID>/secrets/<SECRET_ID>/versions/<VERSION_ID>.

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 Sourcedb to Spanner template.
5. In the provided parameter fields, enter your parameter values.
6. Click Run job.

gcloud CLI

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/Sourcedb_to_Spanner_Flex \
    --project=PROJECT_ID \
    --region=REGION_NAME \
    --parameters \
       sourceConfigURL=SOURCE_CONFIG_URL,\
       instanceId=INSTANCE_ID,\
       databaseId=DATABASE_ID,\
       projectId=PROJECT_ID,\
       outputDirectory=OUTPUT_DIRECTORY,\

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
• SOURCE_CONFIG_URL: the URL to connect to the source database host. It can be either of 1. The JDBC connection URL - which must contain the host, port and source db name and can optionally contain properties like autoReconnect, maxReconnects etc. Format: `jdbc:mysql://{host}:{port}/{dbName}?{parameters}`2. The shard config path
• INSTANCE_ID: the Cloud Spanner Instance Id.
• DATABASE_ID: the Cloud Spanner Database Id.
• PROJECT_ID: the Cloud Spanner Project Id.
• OUTPUT_DIRECTORY: the Output directory for failed/skipped/filtered events

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": {
       "sourceConfigURL": "SOURCE_CONFIG_URL",
       "instanceId": "INSTANCE_ID",
       "databaseId": "DATABASE_ID",
       "projectId": "PROJECT_ID",
       "outputDirectory": "OUTPUT_DIRECTORY",
     },
     "containerSpecGcsPath": "gs://dataflow-templates-LOCATION/VERSION/flex/Sourcedb_to_Spanner_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
• SOURCE_CONFIG_URL: the URL to connect to the source database host. It can be either of 1. The JDBC connection URL - which must contain the host, port and source db name and can optionally contain properties like autoReconnect, maxReconnects etc. Format: `jdbc:mysql://{host}:{port}/{dbName}?{parameters}`2. The shard config path
• INSTANCE_ID: the Cloud Spanner Instance Id.
• DATABASE_ID: the Cloud Spanner Database Id.
• PROJECT_ID: the Cloud Spanner Project Id.
• OUTPUT_DIRECTORY: the Output directory for failed/skipped/filtered events

Template source code

Java

/*
 * Copyright (C) 2024 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.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.SourceDbToSpannerOptions;
import com.google.cloud.teleport.v2.spanner.migrations.shard.Shard;
import com.google.cloud.teleport.v2.spanner.migrations.utils.SecretManagerAccessorImpl;
import com.google.cloud.teleport.v2.spanner.migrations.utils.ShardFileReader;
import com.google.common.annotations.VisibleForTesting;
import java.util.List;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.io.gcp.spanner.SpannerConfig;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.options.ValueProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A template that copies data from a relational database using JDBC to an existing Spanner
 * database.
 *
 * <p>Check out <a
 * href="https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/main/v2/sourcedb-to-spanner/README_Sourcedb_to_Spanner_Flex.md">README</a>
 * for instructions on how to use or modify this template.
 */
@Template(
    name = "Sourcedb_to_Spanner_Flex",
    category = TemplateCategory.BATCH,
    displayName = "Sourcedb to Spanner",
    description = {
      "The SourceDB to Spanner template is a batch pipeline that copies data from a relational"
          + " database into an existing Spanner database. This pipeline uses JDBC to connect to"
          + " the relational database. You can use this template to copy data from any relational"
          + " database with available JDBC drivers into Spanner. This currently only supports a limited set of types of MySQL",
      "For an extra layer of protection, you can also pass in a Cloud KMS key along with a"
          + " Base64-encoded username, password, and connection string parameters encrypted with"
          + " the Cloud KMS key. See the <a"
          + " href=\"https://cloud.google.com/kms/docs/reference/rest/v1/projects.locations.keyRings.cryptoKeys/encrypt\">Cloud"
          + " KMS API encryption endpoint</a> for additional details on encrypting your username,"
          + " password, and connection string parameters."
    },
    optionsClass = SourceDbToSpannerOptions.class,
    flexContainerName = "source-db-to-spanner",
    documentation =
        "https://cloud.google.com/dataflow/docs/guides/templates/provided/sourcedb-to-spanner",
    contactInformation = "https://cloud.google.com/support",
    preview = true,
    requirements = {
      "The JDBC drivers for the relational database must be available.",
      "The Spanner tables must exist before pipeline execution.",
      "The Spanner tables must have a compatible schema.",
      "The relational database must be accessible from the subnet where Dataflow runs."
    })
public class SourceDbToSpanner {

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

  /**
   * Main entry point for executing the pipeline. This will run the pipeline asynchronously. If
   * blocking execution is required, use the {@link SourceDbToSpanner#run} 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
    SourceDbToSpannerOptions options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(SourceDbToSpannerOptions.class);
    run(options);
  }

  /**
   * Create the pipeline with the supplied options.
   *
   * @param options The execution parameters to the pipeline.
   * @return The result of the pipeline execution.
   */
  @VisibleForTesting
  static PipelineResult run(SourceDbToSpannerOptions options) {
    // TODO - Validate if options are as expected
    Pipeline pipeline = Pipeline.create(options);

    SpannerConfig spannerConfig = createSpannerConfig(options);

    // Decide type and source of migration
    // TODO(vardhanvthigle): Move this within pipelineController.
    switch (options.getSourceDbDialect()) {
      case SourceDbToSpannerOptions.CASSANDRA_SOURCE_DIALECT:
        return PipelineController.executeCassandraMigration(options, pipeline, spannerConfig);
      default:
        /* Implementation detail, not having a default leads to failure in compile time checks enforced here */
        /* Making jdbc as default case which includes MYSQL and PG. */
        return executeJdbcMigration(options, pipeline, spannerConfig);
    }
  }

  // TODO(vardhanvthigle): Move this within pipelineController.
  private static PipelineResult executeJdbcMigration(
      SourceDbToSpannerOptions options, Pipeline pipeline, SpannerConfig spannerConfig) {
    if (options.getSourceConfigURL().startsWith("gs://")) {
      List<Shard> shards =
          new ShardFileReader(new SecretManagerAccessorImpl())
              .readForwardMigrationShardingConfig(options.getSourceConfigURL());
      return PipelineController.executeJdbcShardedMigration(
          options, pipeline, shards, spannerConfig);
    } else {
      return PipelineController.executeJdbcSingleInstanceMigration(
          options, pipeline, spannerConfig);
    }
  }

  @VisibleForTesting
  static SpannerConfig createSpannerConfig(SourceDbToSpannerOptions options) {
    return SpannerConfig.create()
        .withProjectId(ValueProvider.StaticValueProvider.of(options.getProjectId()))
        .withHost(ValueProvider.StaticValueProvider.of(options.getSpannerHost()))
        .withInstanceId(ValueProvider.StaticValueProvider.of(options.getInstanceId()))
        .withDatabaseId(ValueProvider.StaticValueProvider.of(options.getDatabaseId()));
  }
}