Hi Dominik, the reason why the AsyncFunction does not support state atm is that we would to have make sure that the right key is set not only when open and asyncInvoke is set but also when a potential asynchronous callback is being executed. It would be super easy to define a callback which keeps a reference to the state object. If the right key is not set when the callback is being executed, then you easily can corrupt your state. Moreover, all state accesses need to run under the checkpoint lock. Due to these problems, we decided to not support state for AsyncFunctions. Said differently, if state accesses would set the right key and execute under the checkpoint lock, then one could support state for AsyncFunctions.
Cheers, Till On Tue, Apr 30, 2019 at 12:20 PM Dominik Wosiński <wos...@gmail.com> wrote: > Hey, Currently when trying to get the state inside the *open* method for > Flink RichAsyncFunction we will get *State is not supported in rich async > functions *exception.Why doesn't AsyncFunction support state ? > > Thanks in advance, > Best Regards, > Dom. >
