/*
* Copyright (C) 2019 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.bigtable;
import static com.google.cloud.teleport.bigtable.BigtableToAvro.toByteArray;
import com.google.bigtable.v2.Cell;
import com.google.bigtable.v2.Column;
import com.google.bigtable.v2.Family;
import com.google.bigtable.v2.Row;
import com.google.cloud.teleport.bigtable.BigtableToParquet.Options;
import com.google.cloud.teleport.metadata.Template;
import com.google.cloud.teleport.metadata.TemplateCategory;
import com.google.cloud.teleport.metadata.TemplateParameter;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import org.apache.avro.generic.GenericRecord;
import org.apache.avro.generic.GenericRecordBuilder;
import org.apache.beam.runners.dataflow.options.DataflowPipelineOptions;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.extensions.avro.coders.AvroCoder;
import org.apache.beam.sdk.io.FileIO;
import org.apache.beam.sdk.io.gcp.bigtable.BigtableIO;
import org.apache.beam.sdk.io.parquet.ParquetIO;
import org.apache.beam.sdk.options.Default;
import org.apache.beam.sdk.options.PipelineOptions;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.options.ValueProvider;
import org.apache.beam.sdk.transforms.MapElements;
import org.apache.beam.sdk.transforms.SimpleFunction;
import org.apache.beam.sdk.values.PCollection;
/**
* Dataflow pipeline that exports data from a Cloud Bigtable table to Parquet files in GCS.
* Currently, filtering on Cloud Bigtable table is not supported.
*
* <p>Check out <a
* href="https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/main/v1/README_Cloud_Bigtable_to_GCS_Parquet.md">README</a>
* for instructions on how to use or modify this template.
*/
@Template(
name = "Cloud_Bigtable_to_GCS_Parquet",
category = TemplateCategory.BATCH,
displayName = "Cloud Bigtable to Parquet Files on Cloud Storage",
description =
"The Bigtable to Cloud Storage Parquet template is a pipeline that reads data from a Bigtable table and writes it to a Cloud Storage bucket in Parquet format. "
+ "You can use the template to move data from Bigtable to Cloud Storage.",
optionsClass = Options.class,
documentation =
"https://cloud.google.com/dataflow/docs/guides/templates/provided/bigtable-to-parquet",
contactInformation = "https://cloud.google.com/support",
requirements = {
"The Bigtable table must exist.",
"The output Cloud Storage bucket must exist before running the pipeline."
})
public class BigtableToParquet {
/** Options for the export pipeline. */
public interface Options extends PipelineOptions {
@TemplateParameter.ProjectId(
order = 1,
description = "Project ID",
helpText =
"The ID of the Google Cloud project of the Cloud Bigtable instance that you want to read data from")
ValueProvider<String> getBigtableProjectId();
@SuppressWarnings("unused")
void setBigtableProjectId(ValueProvider<String> projectId);
@TemplateParameter.Text(
order = 2,
regexes = {"[a-z][a-z0-9\\-]+[a-z0-9]"},
description = "Instance ID",
helpText = "The ID of the Cloud Bigtable instance that contains the table")
ValueProvider<String> getBigtableInstanceId();
@SuppressWarnings("unused")
void setBigtableInstanceId(ValueProvider<String> instanceId);
@TemplateParameter.Text(
order = 3,
regexes = {"[_a-zA-Z0-9][-_.a-zA-Z0-9]*"},
description = "Table ID",
helpText = "The ID of the Cloud Bigtable table to export")
ValueProvider<String> getBigtableTableId();
@SuppressWarnings("unused")
void setBigtableTableId(ValueProvider<String> tableId);
@TemplateParameter.GcsWriteFolder(
order = 4,
description = "Output file directory in Cloud Storage",
helpText =
"The path and filename prefix for writing output files. Must end with a slash. DateTime formatting is used to parse directory path for date & time formatters.",
example = "gs://your-bucket/your-path")
ValueProvider<String> getOutputDirectory();
@SuppressWarnings("unused")
void setOutputDirectory(ValueProvider<String> outputDirectory);
@TemplateParameter.Text(
order = 5,
description = "Parquet file prefix",
helpText = "The prefix of the Parquet file name. For example, \"table1-\"")
@Default.String("part")
ValueProvider<String> getFilenamePrefix();
@SuppressWarnings("unused")
void setFilenamePrefix(ValueProvider<String> filenamePrefix);
@TemplateParameter.Integer(
order = 6,
optional = true,
description = "Maximum output shards",
helpText =
"The maximum number of output shards produced when writing. A higher number of "
+ "shards means higher throughput for writing to Cloud Storage, but potentially higher "
+ "data aggregation cost across shards when processing output Cloud Storage files. "
+ "Default value is decided by Dataflow.")
@Default.Integer(0)
ValueProvider<Integer> getNumShards();
@SuppressWarnings("unused")
void setNumShards(ValueProvider<Integer> numShards);
}
/**
* Main entry point for pipeline execution.
*
* @param args Command line arguments to the pipeline.
*/
public static void main(String[] args) {
Options options = PipelineOptionsFactory.fromArgs(args).withValidation().as(Options.class);
PipelineResult result = run(options);
// Wait for pipeline to finish only if it is not constructing a template.
if (options.as(DataflowPipelineOptions.class).getTemplateLocation() == null) {
result.waitUntilFinish();
}
}
/**
* Runs a pipeline to export data from a Cloud Bigtable table to Parquet file(s) in GCS.
*
* @param options arguments to the pipeline
*/
public static PipelineResult run(Options options) {
Pipeline pipeline = Pipeline.create(PipelineUtils.tweakPipelineOptions(options));
BigtableIO.Read read =
BigtableIO.read()
.withProjectId(options.getBigtableProjectId())
.withInstanceId(options.getBigtableInstanceId())
.withTableId(options.getBigtableTableId());
// Do not validate input fields if it is running as a template.
if (options.as(DataflowPipelineOptions.class).getTemplateLocation() != null) {
read = read.withoutValidation();
}
/**
* Steps: 1) Read records from Bigtable. 2) Convert a Bigtable Row to a GenericRecord. 3) Write
* GenericRecord(s) to GCS in parquet format.
*/
pipeline
.apply("Read from Bigtable", read)
.apply("Transform to Parquet", MapElements.via(new BigtableToParquetFn()))
.setCoder(AvroCoder.of(GenericRecord.class, BigtableRow.getClassSchema()))
.apply(
"Write to Parquet in GCS",
FileIO.<GenericRecord>write()
.via(ParquetIO.sink(BigtableRow.getClassSchema()))
.to(options.getOutputDirectory())
.withPrefix(options.getFilenamePrefix())
.withSuffix(".parquet")
.withNumShards(options.getNumShards()));
return pipeline.run();
}
/**
* Translates a {@link PCollection} of Bigtable {@link Row} to a {@link PCollection} of {@link
* GenericRecord}.
*/
static class BigtableToParquetFn extends SimpleFunction<Row, GenericRecord> {
@Override
public GenericRecord apply(Row row) {
ByteBuffer key = ByteBuffer.wrap(toByteArray(row.getKey()));
List<BigtableCell> cells = new ArrayList<>();
for (Family family : row.getFamiliesList()) {
String familyName = family.getName();
for (Column column : family.getColumnsList()) {
ByteBuffer qualifier = ByteBuffer.wrap(toByteArray(column.getQualifier()));
for (Cell cell : column.getCellsList()) {
long timestamp = cell.getTimestampMicros();
ByteBuffer value = ByteBuffer.wrap(toByteArray(cell.getValue()));
cells.add(new BigtableCell(familyName, qualifier, timestamp, value));
}
}
}
return new GenericRecordBuilder(BigtableRow.getClassSchema())
.set("key", key)
.set("cells", cells)
.build();
}
}
}
