[IGNITE-19889] Implement observable timestamp on server

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-beta2
• Labels: ignite-3
• Epic Link: RO transaction in past
• Assignee: Vladislav Pyatkov
• Reporter: Vladislav Pyatkov
• Created: 29/Jun/23 17:58
• Updated: 01/Sep/23 11:00
• Resolved: 01/Sep/23 11:00

Description

Motivation
Client timestamp is used to determine a read timestamp for RO transaction on client-side (IGNITE-19888). For consistency behavior, need to implement a similar timestamp on server.

Implementation note
The last server observable timestamp should update at least when the transaction commuted.
Any RO transaction should use the timestamp: for SQL (IGNITE-19898) and through key-value API (IGNITE-19887)

Definition of done
All serve-side created RO transactions should execute in past with timestamp has been determining by last observation time.

Issue Links

• is blocked by: IGNITE-19887 Transfer observable timestamp to read-only transaction
• is blocked by: IGNITE-19898 SQL implicit RO transaction should used observation timestamp
• is related to: IGNITE-19824 Implicit RO should be used in implicit single gets
• links to: GitHub Pull Request #2514