google-cloud-platform - 如何计算Google Dataflow文件处理的输入文件中的行数？

Question

我正在尝试计算输入文件中的行数，并且我正在使用 Cloud dataflow Runner 创建模板。在下面的代码中，我从 GCS 存储桶中读取文件，对其进行处理，然后将输出存储在 Redis 实例中。

但是我无法计算输入文件的行数。

主类

 public static void main(String[] args) {
    /**
     * Constructed StorageToRedisOptions object using the method PipelineOptionsFactory.fromArgs to read options from command-line
     */
    StorageToRedisOptions options = PipelineOptionsFactory.fromArgs(args)
            .withValidation()
            .as(StorageToRedisOptions.class);

    Pipeline p = Pipeline.create(options);
    p.apply("Reading Lines...", TextIO.read().from(options.getInputFile()))
            .apply("Transforming data...",
                    ParDo.of(new DoFn<String, String[]>() {
                        @ProcessElement
                        public void TransformData(@Element String line, OutputReceiver<String[]> out) {
                            String[] fields = line.split("\\|");
                            out.output(fields);
                        }
                    }))
            .apply("Processing data...",
                    ParDo.of(new DoFn<String[], KV<String, String>>() {
                        @ProcessElement
                        public void ProcessData(@Element String[] fields, OutputReceiver<KV<String, String>> out) {
                            if (fields[RedisIndex.GUID.getValue()] != null) {

                                out.output(KV.of("firstname:"
                                        .concat(fields[RedisIndex.FIRSTNAME.getValue()]), fields[RedisIndex.GUID.getValue()]));

                                out.output(KV.of("lastname:"
                                        .concat(fields[RedisIndex.LASTNAME.getValue()]), fields[RedisIndex.GUID.getValue()]));

                                out.output(KV.of("dob:"
                                        .concat(fields[RedisIndex.DOB.getValue()]), fields[RedisIndex.GUID.getValue()]));

                                out.output(KV.of("postalcode:"
                                        .concat(fields[RedisIndex.POSTAL_CODE.getValue()]), fields[RedisIndex.GUID.getValue()]));

                            }
                        }
                    }))
            .apply("Writing field indexes into redis",
            RedisIO.write().withMethod(RedisIO.Write.Method.SADD)
                    .withEndpoint(options.getRedisHost(), options.getRedisPort()));
    p.run();

}

示例输入文件

xxxxxxxxxxxxxxxx|bruce|wayne|31051989|444444444444
yyyyyyyyyyyyyyyy|selina|thomas|01051989|222222222222
aaaaaaaaaaaaaaaa|clark|kent|31051990|666666666666

执行管道的命令

mvn compile exec:java \
  -Dexec.mainClass=com.viveknaskar.DataFlowPipelineForMemStore \
  -Dexec.args="--project=my-project-id \
  --jobName=dataflow-job \
  --inputFile=gs://my-input-bucket/*.txt \
  --redisHost=127.0.0.1 \
  --stagingLocation=gs://pipeline-bucket/stage/ \
  --dataflowJobFile=gs://pipeline-bucket/templates/dataflow-template \
  --runner=DataflowRunner"

我尝试使用 StackOverflow solution 中的以下代码但这对我不起作用。

PipelineOptions options = ...;
DirectPipelineRunner runner = DirectPipelineRunner.fromOptions(options);
Pipeline p = Pipeline.create(options);
PCollection<Long> countPC =
    p.apply(TextIO.Read.from("gs://..."))
     .apply(Count.<String>globally());
DirectPipelineRunner.EvaluationResults results = runner.run(p);
long count = results.getPCollection(countPC).get(0);

我也浏览了 Apache Beam 文档，但没有找到任何有用的信息。对此的任何帮助将不胜感激。

Answer 1

我通过添加 Count.globally() 解决了这个问题并申请 PCollection<String>管道读取文件后。

我添加了以下代码:

PCollection<String> lines = p.apply("Reading Lines...", TextIO.read().from(options.getInputFile()));

 lines.apply(Count.globally()).apply("Count the total records", ParDo.of(new RecordCount()));

我在其中创建了一个新类 (RecordCount.java)，它扩展了 DoFn ，它只记录计数。

RecordCount.java

import org.apache.beam.sdk.transforms.DoFn;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class RecordCount extends DoFn<Long, Void> {

    private static final Logger LOGGER = LoggerFactory.getLogger(RecordCount.class);

    @ProcessElement
    public void processElement(@Element Long count) {
       LOGGER.info("The total number of records in the input file is: ", count);

        }
    }

}