[FLINK-17898] Remove Exceptions from signatures of SourceOutput methods

• Type: Sub-task
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 1.11.0
• Component/s: API / DataStream
• Assignee: Stephan Ewen
• Reporter: Stephan Ewen
• Created: 23/May/20 20:10
• Updated: 27/May/20 20:12
• Resolved: 27/May/20 20:12

Description

The collect(...) methods in SourceOutput currently declare that they can trow Exception.
That was originally introduced, because it can be the case when pushing records into the chain.

However, one can argue that the Source Reader that calls these methods is in no way supposed to handle these exceptions, because they come from downstream operator failures. Because of that, we should go for unchecked exceptions and handle downstream exceptions via ExceptionInChainedOperatorException.