The desire was to avoid the implicit disallowed combination wart in Python (until we could make sense of it), and also ValueState could be surprising with respect to older values overwriting newer ones. What was the specific example that was less natural?
On Thu, Apr 25, 2019 at 3:01 PM Maximilian Michels <m...@apache.org> wrote: > > @Pablo: Thanks for following up with the PR! :) > > @Brian: I was wondering about this as well. It makes the Python state > code a bit unnatural. I'd suggest to add a ValueState wrapper around > ListState/CombiningState. > > @Robert: Like Reuven pointed out, we can disallow ValueState for merging > windows with state. > > @Reza: Great. Let's make sure it has Python examples out of the box. > Either Pablo or me could help there. > > Thanks, > Max > > On 25.04.19 04:14, Reza Ardeshir Rokni wrote: > > Pablo, Kenneth and I have a new blog ready for publication which covers > > how to create a "looping timer" it allows for default values to be > > created in a window when no incoming elements exists. We just need to > > clear a few bits before publication, but would be great to have that > > also include a python example, I wrote it in java... > > > > Cheers > > > > Reza > > > > On Thu, 25 Apr 2019 at 04:34, Reuven Lax <re...@google.com > > <mailto:re...@google.com>> wrote: > > > > Well state is still not implemented for merging windows even for > > Java (though I believe the idea was to disallow ValueState there). > > > > On Wed, Apr 24, 2019 at 1:11 PM Robert Bradshaw <rober...@google.com > > <mailto:rober...@google.com>> wrote: > > > > It was unclear what the semantics were for ValueState for merging > > windows. (It's also a bit weird as it's inherently a race condition > > wrt element ordering, unlike Bag and CombineState, though you can > > always implement it as a CombineState that always returns the latest > > value which is a bit more explicit about the dangers here.) > > > > On Wed, Apr 24, 2019 at 10:08 PM Brian Hulette > > <bhule...@google.com <mailto:bhule...@google.com>> wrote: > > > > > > That's a great idea! I thought about this too after those > > posts came up on the list recently. I started to look into it, > > but I noticed that there's actually no implementation of > > ValueState in userstate. Is there a reason for that? I started > > to work on a patch to add it but I was just curious if there was > > some reason it was omitted that I should be aware of. > > > > > > We could certainly replicate the example without ValueState > > by using BagState and clearing it before each write, but it > > would be nice if we could draw a direct parallel. > > > > > > Brian > > > > > > On Fri, Apr 12, 2019 at 7:05 AM Maximilian Michels > > <m...@apache.org <mailto:m...@apache.org>> wrote: > > >> > > >> > It would probably be pretty easy to add the corresponding > > code snippets to the docs as well. > > >> > > >> It's probably a bit more work because there is no section > > dedicated to > > >> state/timer yet in the documentation. Tracked here: > > >> https://jira.apache.org/jira/browse/BEAM-2472 > > >> > > >> > I've been going over this topic a bit. I'll add the > > snippets next week, if that's fine by y'all. > > >> > > >> That would be great. The blog posts are a great way to get > > started with > > >> state/timers. > > >> > > >> Thanks, > > >> Max > > >> > > >> On 11.04.19 20:21, Pablo Estrada wrote: > > >> > I've been going over this topic a bit. I'll add the > > snippets next week, > > >> > if that's fine by y'all. > > >> > Best > > >> > -P. > > >> > > > >> > On Thu, Apr 11, 2019 at 5:27 AM Robert Bradshaw > > <rober...@google.com <mailto:rober...@google.com> > > >> > <mailto:rober...@google.com <mailto:rober...@google.com>>> > > wrote: > > >> > > > >> > That's a great idea! It would probably be pretty easy > > to add the > > >> > corresponding code snippets to the docs as well. > > >> > > > >> > On Thu, Apr 11, 2019 at 2:00 PM Maximilian Michels > > <m...@apache.org <mailto:m...@apache.org> > > >> > <mailto:m...@apache.org <mailto:m...@apache.org>>> wrote: > > >> > > > > >> > > Hi everyone, > > >> > > > > >> > > The Python SDK still lacks documentation on state > > and timers. > > >> > > > > >> > > As a first step, what do you think about updating > > these two blog > > >> > posts > > >> > > with the corresponding Python code? > > >> > > > > >> > > > > https://beam.apache.org/blog/2017/02/13/stateful-processing.html > > >> > > > > https://beam.apache.org/blog/2017/08/28/timely-processing.html > > >> > > > > >> > > Thanks, > > >> > > Max > > >> > > >
