【发布时间】：2018-12-22 07:02:42
【问题描述】：
我有一些 Spark 代码，它从 HDFS 读取两个文件（一个头文件和一个正文文件），将 RDD[String] 缩减为单个分区，然后使用 GZip 编解码器将结果作为压缩文件写入：
spark.sparkContext.textFile("path_to_header.txt,path_to_body.txt")
.coalesce(1)
.saveAsTextFile("output_path", classOf[GzipCodec])
这按预期 100% 有效。我们现在被要求为无法本地解压缩 *.gzip 文件的 Windows 用户支持 zip 压缩。显然，zip 格式不受本机支持，所以我正在尝试推出自己的压缩编解码器。
我在运行代码时遇到了“ZipException: no current ZIP entry”异常：
Exception occured while exporting org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 16.0 failed 2 times, most recent failure: Lost task 0.1 in stage 16.0 (TID 675, xxxxxxx.xxxxx.xxx, executor 16): java.util.zip.ZipException: no current ZIP entry
at java.util.zip.ZipOutputStream.write(Unknown Source)
at io.ZipCompressorStream.write(ZipCompressorStream.java:23)
at java.io.DataOutputStream.write(Unknown Source)
at org.apache.hadoop.mapred.TextOutputFormat$LineRecordWriter.writeObject(TextOutputFormat.java:81)
at org.apache.hadoop.mapred.TextOutputFormat$LineRecordWriter.write(TextOutputFormat.java:102)
at org.apache.spark.SparkHadoopWriter.write(SparkHadoopWriter.scala:95)
at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13$$anonfun$apply$7.apply$mcV$sp(PairRDDFunctions.scala:1205)
at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13$$anonfun$apply$7.apply(PairRDDFunctions.scala:1203)
at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13$$anonfun$apply$7.apply(PairRDDFunctions.scala:1203)
at org.apache.spark.util.Utils$.tryWithSafeFinallyAndFailureCallbacks(Utils.scala:1348)
at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13.apply(PairRDDFunctions.scala:1211)
at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13.apply(PairRDDFunctions.scala:1190)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:70)
at org.apache.spark.scheduler.Task.run(Task.scala:86)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
我创建了一个扩展 DefaultCodec 的 ZipCodec 类：
public class ZipCodec extends DefaultCodec {
@Override
public CompressionOutputStream createOutputStream(final OutputStream out, final Compressor compressor) throws IOException {
return new ZipCompressorStream(new ZipOutputStream(out));
}
以及扩展 CompressorStream 的 ZipCompressorStream：
public class ZipCompressorStream extends CompressorStream {
public ZipCompressorStream(final ZipOutputStream out) {
super(out);
}
@Override
public void write(final int b) throws IOException {
out.write(b);
}
@Override
public void write(final byte[] data, final int offset, final int length) throws IOException {
out.write(data, offset, length);
}
我们目前使用的是 Spark 1.6.0 和 Hadoop 2.6.0-cdh5.8.2
有什么想法吗？
提前致谢！
【问题讨论】：
标签： apache-spark hadoop compression hdfs rdd