[SPARK-17356] A large Metadata filed in Alias can cause OOM when calling TreeNode.toJSON

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.6.3, 2.0.1, 2.1.0
• Component/s: SQL
• Target Version/s: 1.6.3, 2.0.1, 2.1.0
• Assignee: Sean Zhong
• Reporter: Sean Zhong
• Created: 01/Sep/16 05:57
• Updated: 06/Sep/16 12:08
• Resolved: 06/Sep/16 08:08

Description

When using MLLib, when calling toJSON on a plan with many level of sub-queries, it may cause out of memory exception with stack trace like this

java.lang.OutOfMemoryError: GC overhead limit exceeded
	at scala.collection.mutable.AbstractSeq.<init>(Seq.scala:47)
	at scala.collection.mutable.AbstractBuffer.<init>(Buffer.scala:48)
	at scala.collection.mutable.ListBuffer.<init>(ListBuffer.scala:46)
	at scala.collection.immutable.List$.newBuilder(List.scala:396)
	at scala.collection.generic.GenericTraversableTemplate$class.newBuilder(GenericTraversableTemplate.scala:64)
	at scala.collection.AbstractTraversable.newBuilder(Traversable.scala:105)
	at scala.collection.TraversableLike$class.filter(TraversableLike.scala:262)
	at scala.collection.AbstractTraversable.filter(Traversable.scala:105)
	at scala.collection.TraversableLike$class.filterNot(TraversableLike.scala:274)
	at scala.collection.AbstractTraversable.filterNot(Traversable.scala:105)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:25)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:20)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:25)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:25)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:25)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:25)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:20)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:20)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:25)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:20)
	at org.json4s.jackson.JValueSerializer.serialize(JValueSerializer.scala:7)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:128)
	at com.fasterxml.jackson.databind.ObjectMapper._configAndWriteValue(ObjectMapper.java:2881)
	at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:2338)
	at org.json4s.jackson.JsonMethods$class.compact(JsonMethods.scala:34)
	at org.json4s.jackson.JsonMethods$.compact(JsonMethods.scala:50)
	at org.apache.spark.sql.catalyst.trees.TreeNode.toJSON(TreeNode.scala:566)

The query plan, stack trace, and jmap distribution is attached.

Issue Links

• links to: [Github] Pull Request #14915 (clockfly)
• links to: [Github] Pull Request #14973 (clockfly)