I intend to augment every event in a session with a unique ID. To keep
the session lean, there is a PurgingTrigger on this aggregate that fires
on a count of 1.
>> (except that the number of keys can grow).
Want to confirm that the keys are GCed ( along with state ) once the
(windows close + lateness ) ?
On Fri, Mar 12, 2021 at 5:32 AM Roman Khachatryan <ro...@apache.org> wrote:
> Hi Vishal,
>
> There is no leak in the code you provided (except that the number of
> keys can grow).
> But as you figured out the state is scoped to key, not to window+key.
>
> Could you explain what you are trying to achieve and why do you need to
> combine
> sliding windows with state scoped to window+key?
>
> Regards,
> Roman
>
> On Fri, Mar 12, 2021 at 5:13 AM Vishal Santoshi
> <vishal.santo...@gmail.com> wrote:
> >
> > Essentially, Does this code leak state
> >
> > private static class SessionIdProcessWindowFunction<KEY extends
> java.io.Serializable, VALUE extends java.io.Serializable>
> > extends
> > ProcessWindowFunction<KeyedSession<KEY, VALUE>,
> KeyedSessionWithSessionID<KEY, VALUE>, KEY, TimeWindow> {
> > private static final long serialVersionUID = 1L;
> > private final static ValueStateDescriptor<String> sessionId = new
> ValueStateDescriptor<String>("session_uid",
> > String.class);
> >
> > @Override
> > public void process(KEY key,
> > ProcessWindowFunction<KeyedSession<KEY, VALUE>,
> KeyedSessionWithSessionID<KEY, VALUE>, KEY, TimeWindow>.Context context,
> > Iterable<KeyedSession<KEY, VALUE>> elements,
> Collector<KeyedSessionWithSessionID<KEY, VALUE>> out)
> > throws Exception {
> > // I need this scoped to key/window
> > if (getRuntimeContext().getState(sessionId).value() == null) {
> > UUID uuid = UUID.randomUUID();
> > getRuntimeContext().getState(sessionId).update(uuid.toString());
> > }
> > String uuid = getRuntimeContext().getState(sessionId).value();
> > out.collect(new KeyedSessionWithSessionID<>(elements.iterator().next(),
> uuid));
> > }
> > }
> >
> > On Thu, Mar 11, 2021 at 11:09 PM Vishal Santoshi <
> vishal.santo...@gmail.com> wrote:
> >>
> >> Hello folks,
> >> The suggestion is to use windowState() for a key key
> per window state and clear the state explicitly. Also it seems that
> getRuntime().getState() will return a globalWindow() where state is shared
> among windows with the same key. I desire of course to have state scoped to
> a key per window and was wanting to use windowState().. The caveat is that
> my window is a Session Window and when I try to use clear() I am thrown
> this exception ( Session Windows are Merging Windows )
> >>
> >> Caused by: java.lang.UnsupportedOperationException: Per-window state is
> not allowed when using merging windows.
> >>
> >>
> >> The questions are
> >>
> >> * How do I have state per session window/ per key and still be able to
> clear it ?
> >> * Does getRuntime().getState() give me the clear() semantics for free
> along with state per window per key and thus I have understood
> getRuntime().getState() wrong ?
> >>
> >> Regards.
> >>
> >>
> >>
>
