[英]Scala Spark Task not serializable error in code
不確定下面的代碼有什么問題,但它拋出
org.apache.spark.SparkException: Task not serializable
錯誤。 谷歌搜索錯誤,但無法解決。
下面是代碼:(可以通過創建新的 Scala 筆記本在community.cloud.databricks.com
上復制粘貼和執行)
import com.google.gson._
object TweetUtils {
case class Tweet(
id : String,
user : String,
userName : String,
text : String,
place : String,
country : String,
lang : String
)
def parseFromJson(lines:Iterator[String]):Iterator[Tweet] = {
val gson = new Gson
lines.map( line => gson.fromJson(line, classOf[Tweet]))
}
def loadData(): RDD[Tweet] = {
val pathToFile = "/FileStore/tables/reduced_tweets-57570.json"
sc.textFile(pathToFile).mapPartitions(parseFromJson(_))
}
def tweetsByUser(): RDD[(String, Iterable[Tweet])] = {
val tweets = loadData
tweets.groupBy(_.user)
}
}
val res = TweetUtils.tweetsByUser()
res.collect().take(5).foreach(println)
下面是詳細的錯誤信息:
at org.apache.spark.util.ClosureCleaner$.ensureSerializable(ClosureCleaner.scala:403)
at org.apache.spark.util.ClosureCleaner$.org$apache$spark$util$ClosureCleaner$$clean(ClosureCleaner.scala:393)
at org.apache.spark.util.ClosureCleaner$.clean(ClosureCleaner.scala:162)
at org.apache.spark.SparkContext.clean(SparkContext.scala:2548)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1.apply(RDD.scala:827)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1.apply(RDD.scala:826)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)
at org.apache.spark.rdd.RDD.withScope(RDD.scala:392)
at org.apache.spark.rdd.RDD.mapPartitions(RDD.scala:826)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw$TweetUtils$.loadData(command-3696793732897971:22)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw$TweetUtils$.tweetsByUser(command-3696793732897971:25)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw.<init>(command-3696793732897971:30)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw$$iw$$iw$$iw.<init>(command-3696793732897971:84)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw$$iw$$iw.<init>(command-3696793732897971:86)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw$$iw.<init>(command-3696793732897971:88)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw$$iw.<init>(command-3696793732897971:90)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw$$iw.<init>(command-3696793732897971:92)
at line05db6d250e4b42e2b2c1d6b97ba83df533.$read$$iw$$iw.<init>(command-3696793732897971:94)
提前致謝,
斯里
最后,有效的方法是將“Artem Aliev”和“Partha”的建議一起實施。 即通過將“case class Tweet”移到“TweetUtils object”之外,並擴展對象“object TweetUtils extends Serializable”
感謝你們倆。
將您的TweetUtils
對象設為可Serializable
,它應該可以工作:
object TweetUtils extends Serializable
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