| # |
| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You 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. |
| # |
| |
| """A Dataflow job that counts the number of rows in a BQ table. |
| |
| Can be configured to simulate slow reading for a given number of rows. |
| """ |
| |
| # pytype: skip-file |
| |
| from __future__ import absolute_import |
| |
| import argparse |
| import logging |
| import random |
| import time |
| |
| import apache_beam as beam |
| from apache_beam.io.gcp.bigquery import _ReadFromBigQuery |
| from apache_beam.options.pipeline_options import GoogleCloudOptions |
| from apache_beam.options.pipeline_options import PipelineOptions |
| from apache_beam.testing.test_pipeline import TestPipeline |
| from apache_beam.testing.util import assert_that |
| from apache_beam.testing.util import equal_to |
| |
| |
| class RowToStringWithSlowDown(beam.DoFn): |
| |
| def process(self, element, num_slow=0, *args, **kwargs): |
| |
| if num_slow == 0: |
| yield ['row'] |
| else: |
| rand = random.random() * 100 |
| if rand < num_slow: |
| time.sleep(0.01) |
| yield ['slow_row'] |
| else: |
| yield ['row'] |
| |
| |
| def run(argv=None): |
| parser = argparse.ArgumentParser() |
| parser.add_argument('--input_table', required=True, |
| help='Input table to process.') |
| parser.add_argument('--num_records', required=True, |
| help='The expected number of records', type=int) |
| parser.add_argument('--num_slow', default=0, |
| help=('Percentage of rows that will be slow. ' |
| 'Must be in the range [0, 100)')) |
| parser.add_argument('--beam_bq_source', default=False, type=bool, |
| help=('Whether to use the new _ReadFromBigQuery' |
| ' transform, or the BigQuerySource.')) |
| known_args, pipeline_args = parser.parse_known_args(argv) |
| |
| options = PipelineOptions(pipeline_args) |
| with TestPipeline(options=options) as p: |
| if known_args.beam_bq_source: |
| reader = _ReadFromBigQuery( |
| table='%s:%s' % (options.view_as(GoogleCloudOptions).project, |
| known_args.input_table)) |
| else: |
| reader = beam.io.Read(beam.io.BigQuerySource(known_args.input_table)) |
| |
| # pylint: disable=expression-not-assigned |
| count = (p | 'read' >> reader |
| | 'row to string' >> beam.ParDo(RowToStringWithSlowDown(), |
| num_slow=known_args.num_slow) |
| | 'count' >> beam.combiners.Count.Globally()) |
| |
| assert_that(count, equal_to([known_args.num_records])) |
| |
| |
| if __name__ == '__main__': |
| logging.getLogger().setLevel(logging.INFO) |
| run() |