Hi, > > This raises a couple of questions: > - Is it a bug though, that the state restoring goes wrong like it does for my > job? Based on my experience it seems like rescaling sometimes works, but then > you can have these random errors.
If there is a problem, I would still consider it a bug because it should work correctly. > - If it's not supported properly, why not refuse to restore a checkpoint if > it would require rescaling? It should work properly, but I would preferred to keep this at the level of a "hidden feature“ until it got some more exposure and also some questions about the future of differences between savepoints and checkpoints are solved. > - We have sometimes had Flink jobs where the state has become so heavy that > cancelling with a savepoint times out & fails. Incremental checkpoints are > still working because they don't timeout as long as the state is growing > linearly. In that case if we want to scale up (for example to enable > successful savepoint creation ;) ), the only thing we can do is to restore > from the latest checkpoint. But then we have no way to scale up by increasing > the cluster size, because we can't create a savepoint with a smaller cluster > but on the other hand can't restore a checkpoint to a bigger cluster, if > rescaling from a checkpoint is not supposed to be relied on. So in this case > we're stuck and forced to start from an empty state? IMO there is a very good chance that this will simply become a normal feature in the near future. Best, Stefan
