我正在尝试使用Spark在S3事件上创建一个简单的SQL查询。我按照以下方式加载了约30GB的JSON文件:
val d2 = spark.read.json("s3n://myData/2017/02/01/1234");
d2.persist(org.apache.spark.storage.StorageLevel.MEMORY_AND_DISK);
d2.registerTempTable("d2");
然后我尝试将查询结果写入文件:
val users_count = sql("select count(distinct data.user_id) from d2");
users_count.write.format("com.databricks.spark.csv").option("header", "true").save("s3n://myfolder/UsersCount.csv");
但是Spark抛出了以下异常:
java.lang.IllegalArgumentException: Size exceeds Integer.MAX_VALUE
at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:869)
at org.apache.spark.storage.DiskStore$$anonfun$getBytes$2.apply(DiskStore.scala:103)
at org.apache.spark.storage.DiskStore$$anonfun$getBytes$2.apply(DiskStore.scala:91)
at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1287)
at org.apache.spark.storage.DiskStore.getBytes(DiskStore.scala:105)
at org.apache.spark.storage.BlockManager.getLocalValues(BlockManager.scala:439)
at org.apache.spark.storage.BlockManager.getOrElseUpdate(BlockManager.scala:672)
at org.apache.spark.rdd.RDD.getOrCompute(RDD.scala:330)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:281)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:79)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:47)
at org.apache.spark.scheduler.Task.run(Task.scala:85)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
请注意,相同的查询在处理少量数据时是没有问题的。这里的问题是什么?
.repartition(100)
等方法,这应该可以解决它。 - elcomendanteval d2 = spark.read.json("s3n://myData/2017/02/01/1234").repartition(1000)
。参考 https://issues.apache.org/jira/browse/SPARK-1476 - undefined_variables3a
而不是s3n
; 参见例如https://dev59.com/Q1wX5IYBdhLWcg3w0SNf - sgvd