[FLINK-20085] Remove RemoteFunctionStateMigrator code paths from StateFun

• Type: Improvement
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: statefun-3.0.0
• Component/s: Stateful Functions
• Labels: pull-request-available

Release Note

Starting from version 2.3.0, directly upgrading from savepoints written with versions earlier than 2.2.0 is no longer supported. This means that users on versions earlier than 2.2.0 and intend to upgrade to 2.3+ need to perform the upgrade incrementally, by first upgrading to 2.2.x, taking a new savepoint, and then upgrading to 2.3+ with the new savepoint.

• Assignee: Tzu-Li (Gordon) Tai
• Reporter: Tzu-Li (Gordon) Tai
• Created: 11/Nov/20 07:37
• Updated: 27/Apr/21 18:03
• Resolved: 14/Nov/20 01:40

Description

The RemoteFunctionStateMigrator was added to allow savepoints with versions <= 2.1.0 to have a migration path for upgrading to versions >= 2.2.0. The binary format of remote function state was changed due to demultiplexed remote state, introduced in 2.2.0.

With 2.2.0 already released with the new formats, it is now safe to fully remove this migration path.

For users, what this means that it would not be possible to directly upgrade from 2.0.x / 2.1.x to 2.3.x+. They'd have to perform incremental upgrades via 2.2.x, by restoring first with 2.2.x and then taking another savepoint, before upgrading to 2.3.x.

Issue Links

• links to: GitHub Pull Request #172