[FLINK-17644] Add support for state TTL in stateful functions

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: statefun-2.1.0
• Component/s: Stateful Functions
• Assignee: Igal Shilman
• Reporter: Igal Shilman
• Created: 12/May/20 19:57
• Updated: 29/May/20 01:28
• Resolved: 18/May/20 19:52

Description

The DataStream API supportsstate TTL, and it can be made accessible to stateful functions users.

To facilitate uses cases as described in http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Window-processing-in-Stateful-Functions-td34966.html

 

The proposed approach would extend the PersistedValue, PersistedTable and PersistedBuffer

with another constructor that accepts ExpireAfter object

which has:

• java time duration
• refresh on read (boolean)

(we should never return an expired entry)

In addition, we need to extend the remote function state to support state expiration.