What do you mean you are blocked? Can't programmers just code up migration tools to the current version of Kryo or whatever serialization platform you choose?
Can't you follow the Kryo migration guide that supports loading data serialized with Kryo v2 and reserializing with Kryo v5? https://github.com/EsotericSoftware/kryo/wiki/Migration-to-v5 I'd presume you would make a tool to upgrade files with Kryo persisted state in savepoints and checkpoints, that would allow for users to register custom serializers. I also presume that new versions of Flink would politely refuse to start with old format state files and require the migration process to be completed. Kryo v2 also pulls in objenesis v2.1 from 2013, before Java 8. Versions older than 3.x aren't supposed to compile nor run correctly under Java 11+. On Thu, Feb 9, 2023 at 2:34 AM Chesnay Schepler <ches...@apache.org> wrote: > > you can't reasonably stay on the 2015 version forever, refuse to > adopt any of the updates or fixes in the 8 years since then, and > reasonably expect things to continue to work well. > > We are well aware that Kryo is a ticking time bomb. > > > Is there any possibility a future release of Flink can upgrade to a > recent version of Kryo serialization? > > Of course there is, but someone needs to figure out a way to do this > without breaking everything or providing a reasonable upgrade path, > which has been blocking us so far. > > On 09/02/2023 07:34, Clayton Wohl wrote: > > I've noticed the latest Flink is using the Kryo serializer library > > version 2.24.0 which is back from 2015! > > > > The Kryo project is actively maintained, it's on version 5.4.0, so > > 2.24.0 is really quite ancient. I presume the concern is maintaining > > compatibility with persisted savepoints. That's a valid concern, but > > you can't reasonably stay on the 2015 version forever, refuse to adopt > > any of the updates or fixes in the 8 years since then, and reasonably > > expect things to continue to work well. > > > > Is there any possibility a future release of Flink can upgrade to a > > recent version of Kryo serialization? > > > > > > > >
