I think the issue is you have to specify a *time *interval for "step." It
would be nice to consider the preceding N minutes as of every message. You
can somewhat approximate that using a very small step.
On Thu, Oct 22, 2020 at 2:29 AM Danny Chan <danny0...@apache.org> wrote:
> The SLIDING window always triggers as of each step, what do you mean by
> "stepless" ?
>
> Alex Cruise <a...@cluonflux.com> 于2020年10月21日周三 上午1:52写道：
>
>> whoops.. as usual, posting led me to find some answers myself. Does this
>> make sense given my requirements?
>>
>> Thanks!
>>
>> private class MyWindowAssigner(val windowSize: Time) :
>> WindowAssigner<Record, TimeWindow>() {
>> private val trigger = CountTrigger.of<TimeWindow>(1) as Trigger<Record
>> TimeWindow>
>>
>> override fun assignWindows(
>> element: Record,
>> timestamp: Long,
>> context: WindowAssignerContext
>> ): MutableCollection<TimeWindow> {
>> return mutableListOf(TimeWindow(timestamp -
>> windowSize.toMilliseconds(), timestamp))
>> }
>>
>> override fun getDefaultTrigger(env: StreamExecutionEnvironment?):
>> Trigger<Record, TimeWindow> {
>> return trigger
>> }
>>
>> override fun getWindowSerializer(executionConfig: ExecutionConfig?):
>> TypeSerializer<TimeWindow> {
>> return TimeWindow.Serializer()
>> }
>>
>> override fun isEventTime(): Boolean {
>> return true
>> }
>> }
>>
>>
>> On Tue, Oct 20, 2020 at 9:13 AM Alex Cruise <a...@cluonflux.com> wrote:
>>
>>> Hey folks!
>>>
>>> I have an application that wants to use "stepless" sliding windows, i.e.
>>> we produce aggregates on every event. The windows need to be of a fixed
>>> size, but to have their start and end times update continuously, and I'd
>>> like to trigger on every event. Is this a bad idea? I've googled and read
>>> the docs extensively and haven't been able to identify built-in
>>> functionality or examples that map cleanly to my requirements.
>>>
>>> OK, I just found DeltaTrigger, which looks promising... Does it make
>>> sense to write a WindowAssigner that makes a new Window on every event,
>>> allocation rates aside?
>>>
>>> Thanks!
>>>
>>> -0xe1a
>>>
>>
--
Jacob Sevart
Software Engineer, Safety
