[FLINK-21392] Support to block in connected streams

• Type: New Feature
• Status: Open
• Priority: Not a Priority
• Resolution: Unresolved
• Component/s: API / DataStream
• Labels: auto-deprioritized-major auto-deprioritized-minor
• Assignee: Unassigned
• Reporter: Timo Walther
• Created: 17/Feb/21 14:38
• Updated: 05/Nov/21 22:38

Description

In many scenarios that involve control streams when using connected streams, users would like to wait until stream A is "ready" before processing the stream B.

Internally we already provide input selectable semantics but with problems around checkpointing. Once those problems are solved, we should expose this functionality in the main API.

Issue Links

• is related to: FLINK-17122 Support InputSelectable and BoundedMultiInput operators with checkpointing
• links to: User ML thread