Question

我有一个火花应用程序。我使用saveAsNewAPIHadoopDataset使用AvroKeyOutputFormat在hdfs上存储rdd。

对于大型RDD，有时我得到了很多ClosedChannelException，应用程序最终会中止。

我在某处读到设置hadoopConf.set("fs.hdfs.impl.disable.cache", "false");有帮助。

以下是我如何保存我的rdd：

        hadoopConf.set("fs.hdfs.impl.disable.cache", "false");
        final Job job = Job.getInstance(hadoopConf);            
        FileOutputFormat.setOutputPath(job, outPutPath);
        AvroJob.setOutputKeySchema(job, MyClass.SCHEMA$);
        job.setOutputFormatClass(AvroKeyOutputFormat.class);

        rdd                    
                .mapToPair(new PreparePairForDatnum())
                .saveAsNewAPIHadoopDataset(job.getConfiguration());

这是堆栈跟踪：

java.nio.channels.ClosedChannelException
    at org.apache.hadoop.hdfs.DFSOutputStream.checkClosed(DFSOutputStream.java:1765)
    at org.apache.hadoop.fs.FSOutputSummer.write(FSOutputSummer.java:108)
    at org.apache.hadoop.fs.FSDataOutputStream$PositionCache.write(FSDataOutputStream.java:58)
    at java.io.DataOutputStream.write(DataOutputStream.java:107)
    at org.apache.avro.file.DataFileWriter$BufferedFileOutputStream$PositionFilter.write(DataFileWriter.java:458)
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
    at java.io.BufferedOutputStream.write(BufferedOutputStream.java:121)
    at org.apache.avro.io.BufferedBinaryEncoder$OutputStreamSink.innerWrite(BufferedBinaryEncoder.java:216)
    at org.apache.avro.io.BufferedBinaryEncoder.writeFixed(BufferedBinaryEncoder.java:150)
    at org.apache.avro.file.DataFileStream$DataBlock.writeBlockTo(DataFileStream.java:369)
    at org.apache.avro.file.DataFileWriter.writeBlock(DataFileWriter.java:395)
    at org.apache.avro.file.DataFileWriter.writeIfBlockFull(DataFileWriter.java:340)
    at org.apache.avro.file.DataFileWriter.append(DataFileWriter.java:311)
    at org.apache.avro.mapreduce.AvroKeyRecordWriter.write(AvroKeyRecordWriter.java:77)
    at org.apache.avro.mapreduce.AvroKeyRecordWriter.write(AvroKeyRecordWriter.java:39)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsNewAPIHadoopDataset$1$$anonfun$12$$anonfun$apply$4.apply$mcV$sp(PairRDDFunctions.scala:1036)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsNewAPIHadoopDataset$1$$anonfun$12$$anonfun$apply$4.apply(PairRDDFunctions.scala:1034)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsNewAPIHadoopDataset$1$$anonfun$12$$anonfun$apply$4.apply(PairRDDFunctions.scala:1034)
    at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1206)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsNewAPIHadoopDataset$1$$anonfun$12.apply(PairRDDFunctions.scala:1042)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsNewAPIHadoopDataset$1$$anonfun$12.apply(PairRDDFunctions.scala:1014)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
    at org.apache.spark.scheduler.Task.run(Task.scala:88)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:214)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
    Suppressed: java.nio.channels.ClosedChannelException
        at org.apache.hadoop.hdfs.DFSOutputStream.checkClosed(DFSOutputStream.java:1765)
        at org.apache.hadoop.fs.FSOutputSummer.write(FSOutputSummer.java:108)
        at org.apache.hadoop.fs.FSDataOutputStream$PositionCache.write(FSDataOutputStream.java:58)
        at java.io.DataOutputStream.write(DataOutputStream.java:107)
        at org.apache.avro.file.DataFileWriter$BufferedFileOutputStream$PositionFilter.write(DataFileWriter.java:458)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
        at java.io.BufferedOutputStream.write(BufferedOutputStream.java:121)
        at org.apache.avro.io.BufferedBinaryEncoder$OutputStreamSink.innerWrite(BufferedBinaryEncoder.java:216)
        at org.apache.avro.io.BufferedBinaryEncoder.writeFixed(BufferedBinaryEncoder.java:150)
        at org.apache.avro.file.DataFileStream$DataBlock.writeBlockTo(DataFileStream.java:369)
        at org.apache.avro.file.DataFileWriter.writeBlock(DataFileWriter.java:395)
        at org.apache.avro.file.DataFileWriter.sync(DataFileWriter.java:413)
        at org.apache.avro.file.DataFileWriter.flush(DataFileWriter.java:422)
        at org.apache.avro.file.DataFileWriter.close(DataFileWriter.java:445)
        at org.apache.avro.mapreduce.AvroKeyRecordWriter.close(AvroKeyRecordWriter.java:83)
        at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsNewAPIHadoopDataset$1$$anonfun$12$$anonfun$apply$5.apply$mcV$sp(PairRDDFunctions.scala:1043)
        at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1215)
        ... 8 more

Answer 1

执行者被杀时可能会发生这种情况。在你的日志中查找类似的东西：

2016-07-20 22:00:42,976 | WARN  | org.apache.spark.scheduler.cluster.YarnSchedulerBackend$YarnSchedulerEndpoint | Container container_e10838_1468831508103_1724_01_055482 on host: hostName was preempted.
2016-07-20 22:00:42,977 | ERROR | org.apache.spark.scheduler.cluster.YarnClusterScheduler | Lost executor 6 on hostName: Container container_e10838_1468831508103_1724_01_055482 on host: hostName was preempted.

如果您发现任务执行者被纱线应用程序主人抢占。换句话说，他被杀了并获得了另一个运行队列。关于抢占和纱线安排可以找到here和here。

由于ClosedChannelException（DFSOutputStream.checkClosed）导致Spark失败

1 个答案: