+1
Sent from my Verizon Wireless 4G LTE smartphone -------- Original message -------- From: Trevor Grant <[email protected]> Date: 11/14/2016 6:49 AM (GMT-08:00) To: [email protected] Subject: [DISCUSS] More meaningful error when running on Spark 2.0 Hi, currently when running on Spark 2.0 the user will hit some sort of error, one such error is: java.util.NoSuchElementException: next on empty iterator at scala.collection.Iterator$$anon$2.next(Iterator.scala:39) at scala.collection.Iterator$$anon$2.next(Iterator.scala:37) at scala.collection.IndexedSeqLike$Elements.next(IndexedSeqLike.scala:63) at scala.collection.IterableLike$class.head(IterableLike.scala:107) at scala.collection.mutable.ArrayOps$ofRef.scala$collection$Ind exedSeqOptimized$$super$head(ArrayOps.scala:186) at scala.collection.IndexedSeqOptimized$class.head(IndexedSeqOp timized.scala:126) at scala.collection.mutable.ArrayOps$ofRef.head(ArrayOps.scala:186) at org.apache.mahout.math.scalabindings.package$$anonfun$1.appl y(package.scala:155) at org.apache.mahout.math.scalabindings.package$$anonfun$1.appl y(package.scala:133) at scala.collection.TraversableLike$$anonfun$map$1.apply(Traver sableLike.scala:234) at scala.collection.TraversableLike$$anonfun$map$1.apply(Traver sableLike.scala:234) at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSe qOptimized.scala:33) at scala.collection.mutable.WrappedArray.foreach(WrappedArray.scala:35) at scala.collection.TraversableLike$class.map(TraversableLike.scala:234) at scala.collection.AbstractTraversable.map(Traversable.scala:104) at org.apache.mahout.math.scalabindings.package$.dense(package.scala:133) at org.apache.mahout.sparkbindings.SparkEngine$.drmSampleKRows( SparkEngine.scala:289) at org.apache.mahout.math.drm.package$.drmSampleKRows(package.scala:149) at org.apache.mahout.math.drm.package$.drmSampleToTSV(package.scala:165) ... 58 elided With the recent Zeppelin-Mahout integration, there are going to be a lot of users unknowingly attempting to run on Mahout on Spark 2.0. I think it would be simple to implement yet save a lot of time on the Zeppelin and Mahout mailing lists to do something like: if sc.version > 1.6.2 then: error("Spark versions ${sc.verion} isn't supported. Please see MAHOUT-... (appropriate jira info)") I'd like to put something together and, depending on how many issues people have on Zeppelin list, be prepared to do a hotfix on 0.12.2 if it becomes prudent. Everyone always complaining that Zeppelin doesn't work because of some mystical error, is bad pr. It DOES say in the notebook and elsewhere that we're not 2.0 compliant, however one of the advantages/drawbacks of Zeppelin is that without having to really know what you're doing you can get a functional local cluster of Flink, Spark, etc. all going. So we easily could have a space where someone read none of the docs, and is whining. Surely few if any would ever do such a thing, but still I think a prudent fix to have in the back pocket. tg Trevor Grant Data Scientist https://github.com/rawkintrevo http://stackexchange.com/users/3002022/rawkintrevo http://trevorgrant.org *"Fortunate is he, who is able to know the causes of things." -Virgil*
