在使用 trainImplicit
时,我一直看到这些警告:
WARN TaskSetManager: Stage 246 contains a task of very large size (208 KB).
The maximum recommended task size is 100 KB.
然后任务大小开始增加。我尝试在输入RDD上调用repartition
,但警告仍然相同。
所有这些警告都来自ALS迭代,来自flatMap和aggregate,例如在flatMap显示这些警告的阶段的起源(使用Spark 1.3.0,但它们也会在Spark 1.3.1中显示):
org.apache.spark.rdd.RDD.flatMap(RDD.scala:296)
org.apache.spark.ml.recommendation.ALS$.org$apache$spark$ml$recommendation$ALS$$computeFactors(ALS.scala:1065)
org.apache.spark.ml.recommendation.ALS$$anonfun$train$3.apply(ALS.scala:530)
org.apache.spark.ml.recommendation.ALS$$anonfun$train$3.apply(ALS.scala:527)
scala.collection.immutable.Range.foreach(Range.scala:141)
org.apache.spark.ml.recommendation.ALS$.train(ALS.scala:527)
org.apache.spark.mllib.recommendation.ALS.run(ALS.scala:203)
而来自聚合:
org.apache.spark.rdd.RDD.aggregate(RDD.scala:968)
org.apache.spark.ml.recommendation.ALS$.computeYtY(ALS.scala:1112)
org.apache.spark.ml.recommendation.ALS$.org$apache$spark$ml$recommendation$ALS$$computeFactors(ALS.scala:1064)
org.apache.spark.ml.recommendation.ALS$$anonfun$train$3.apply(ALS.scala:538)
org.apache.spark.ml.recommendation.ALS$$anonfun$train$3.apply(ALS.scala:527)
scala.collection.immutable.Range.foreach(Range.scala:141)
org.apache.spark.ml.recommendation.ALS$.train(ALS.scala:527)
org.apache.spark.mllib.recommendation.ALS.run(ALS.scala:203)