[FLINK-5876] Mention Scala type fallacies for queryable state client serializers

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.1, 1.3.0
• Component/s: Documentation
• Assignee: Unassigned
• Reporter: Ufuk Celebi
• Created: 21/Feb/17 18:13
• Updated: 22/Feb/17 12:46
• Resolved: 22/Feb/17 12:46

Description

FLINK-5801 shows a very hard to debug issue when querying state from the Scala API that can result in serializer mismatches between the client and the job.

We should mention that the type serializers should be created via the Scala macros.

import org.apache.flink.streaming.api.scala._
...
val keySerializer = createTypeInformation[Long].createSerializer(new ExecutionConfig)