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Tom Hubregtsen commented on SPARK-7002: --------------------------------------- Great, thanks for your help :) I will be happy to propose this. What is the proper way to do this? Do I close this issue, and start a new issue with as type either "New feature" or "Wish" in which I explain what I believe is missing from .toDebugString and why? Anything else I should add? Thanks, Tom Hubregtsen > Persist on RDD fails the second time if the action is called on a child RDD > without showing a FAILED message > ------------------------------------------------------------------------------------------------------------ > > Key: SPARK-7002 > URL: https://issues.apache.org/jira/browse/SPARK-7002 > Project: Spark > Issue Type: Bug > Components: Spark Core > Affects Versions: 1.3.0 > Environment: Platform: Power8 > OS: Ubuntu 14.10 > Java: java-8-openjdk-ppc64el > Reporter: Tom Hubregtsen > Priority: Minor > Labels: disk, persist, unpersist > > The major issue is: Persist on RDD fails the second time if the action is > called on a child RDD without showing a FAILED message. This is pointed out > at 2) > next to this: > toDebugString on a child RDD does not show that the parent RDD is [Disk > Serialized 1x Replicated]. This is pointed out at 1) > Note: I am persisting to disk (DISK_ONLY) to validate that the RDD is or is > not physically stored, as I did not want to solely rely on a missing line in > .toDebugString (see comments in trace) > {code} > scala> val rdd1 = sc.parallelize(List(1,2,3)) > scala> val rdd2 = rdd1.map(x => (x,x+1)) > scala> val rdd3 = rdd2.reduceByKey( (x,y) => x+y) > scala> import org.apache.spark.storage.StorageLevel > scala> rdd2.persist(StorageLevel.DISK_ONLY) > scala> rdd3.collect() > scala> rdd2.toDebugString > res4: String = > (100) MapPartitionsRDD[1] at map at <console>:23 [Disk Serialized 1x > Replicated] > \| CachedPartitions: 100; MemorySize: 0.0 B; TachyonSize: 0.0 B; > DiskSize: 802.0 B > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [Disk > Serialized 1x Replicated] > scala> rdd3.toDebugString > res5: String = > (100) ShuffledRDD[2] at reduceByKey at <console>:25 [] > +-(100) MapPartitionsRDD[1] at map at <console>:23 [] > \| CachedPartitions: 100; MemorySize: 0.0 B; TachyonSize: 0.0 B; > DiskSize: 802.0 B > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [] > // 1) rdd3 does not show that the other RDD's are [Disk Serialized 1x > Replicated], but the data is on disk. This is verified by > // a) The line starting with CachedPartitions > // b) a find in spark_local_dir: "find . -name "\*" \| grep rdd" returns > "./spark-b39bcf9b-e7d7-4284-bdd2-1be7ac3cacef/blockmgr-4f4c0b1c-b47a-4972-b364-7179ea6e0873/1f/rdd_4_*", > where * are the number of partitions > scala> rdd2.unpersist() > scala> rdd2.toDebugString > res8: String = > (100) MapPartitionsRDD[1] at map at <console>:23 [] > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [] > scala> rdd3.toDebugString > res9: String = > (100) ShuffledRDD[2] at reduceByKey at <console>:25 [] > +-(100) MapPartitionsRDD[1] at map at <console>:23 [] > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [] > // successfully unpersisted, also not visible on disk > scala> rdd2.persist(StorageLevel.DISK_ONLY) > scala> rdd3.collect() > scala> rdd2.toDebugString > res18: String = > (100) MapPartitionsRDD[1] at map at <console>:23 [Disk Serialized 1x > Replicated] > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [Disk > Serialized 1x Replicated] > scala> rdd3.toDebugString > res19: String = > (100) ShuffledRDD[2] at reduceByKey at <console>:25 [] > +-(100) MapPartitionsRDD[1] at map at <console>:23 [] > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [] > // 2) The data is not visible on disk though the find command previously > mentioned, and is also not mentioned in the toDebugString (no line starting > with CachedPartitions, even though [Disk Serialized 1x Replicated] is > mentioned). It does work when you call the action on the actual RDD: > scala> rdd2.collect() > scala> rdd2.toDebugString > res21: String = > (100) MapPartitionsRDD[1] at map at <console>:23 [Disk Serialized 1x > Replicated] > \| CachedPartitions: 100; MemorySize: 0.0 B; TachyonSize: 0.0 B; > DiskSize: 802.0 B > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [Disk > Serialized 1x Replicated] > scala> rdd3.toDebugString > res22: String = > (100) ShuffledRDD[2] at reduceByKey at <console>:25 [] > +-(100) MapPartitionsRDD[1] at map at <console>:23 [] > \| CachedPartitions: 100; MemorySize: 0.0 B; TachyonSize: 0.0 B; > DiskSize: 802.0 B > \| ParallelCollectionRDD[0] at parallelize at <console>:21 [] > // Data appears on disk again (using find command preciously mentioned), and > line with CachedPartitions is back in the .toDebugString > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org