Question

启用inferSchema时，从IBM Blue mix对象存储加载的数据框上的count（）会引发以下异常：

Name: org.apache.spark.SparkException
Message: Job aborted due to stage failure: Task 3 in stage 43.0 failed 10 times, most recent failure: Lost task 3.9 in stage 43.0 (TID 166, yp-spark-dal09-env5-0034): java.lang.NumberFormatException: null
    at java.lang.Integer.parseInt(Integer.java:554)
    at java.lang.Integer.parseInt(Integer.java:627)
    at scala.collection.immutable.StringLike$class.toInt(StringLike.scala:272)
    at scala.collection.immutable.StringOps.toInt(StringOps.scala:29)
    at org.apache.spark.sql.execution.datasources.csv.CSVTypeCast$.castTo(CSVInferSchema.scala:241)
    at org.apache.spark.sql.execution.datasources.csv.CSVRelation$$anonfun$csvParser$3.apply(CSVRelation.scala:116)
    at org.apache.spark.sql.execution.datasources.csv.CSVRelation$$anonfun$csvParser$3.apply(CSVRelation.scala:85)
    at org.apache.spark.sql.execution.datasources.csv.CSVFileFormat$$anonfun$buildReader$1$$anonfun$apply$2.apply(CSVFileFormat.scala:128)
    at org.apache.spark.sql.execution.datasources.csv.CSVFileFormat$$anonfun$buildReader$1$$anonfun$apply$2.apply(CSVFileFormat.scala:127)
    at scala.collection.Iterator$$anon$12.nextCur(Iterator.scala:434)
    at scala.collection.Iterator$$anon$12.hasNext(Iterator.scala:440)
    at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
    at org.apache.spark.sql.execution.datasources.FileScanRDD$$anon$1.hasNext(FileScanRDD.scala:91)

如果我禁用inferSchema，我不会得到上述异常。为什么我得到这个例外？默认情况下，如果启用inferSchema，数据桶会读取多少行？

Answer 1

这实际上是spark-csv包裹（null value still not correctly parsed #192）被拖入spark 2.0的问题。它已被更正并推送到spark 2.1。

以下是相关的PR：[SPARK-18269][SQL] CSV datasource should read null properly when schema is lager than parsed tokens。

由于您已经在使用spark 2.0，因此可以轻松升级到2.1并删除该spark-csv包。反正它也不需要。

count throws java.lang.NumberFormatException：在从启用了inferSchema的对象库加载的文件上为null

1 个答案: