Hi, I think you should be able to use state for cleaning up your timers in Trigger.clear(). For this, you have to make sure to not clean up the state in Trigger.onMerge() and instead remove it in Trigger.clear().
I'm not sure whether this will be possible for your use case, though. Best, Aljoscha > On 26. Sep 2017, at 11:17, Stefan Richter <s.rich...@data-artisans.com> wrote: > > Hi, > > I think that it is currently not possible to delete timers that did not > trigger, because currently some of the data structures used for timers do not > support random deletes efficiently. For the second part of the question about > keeping the state of merged windows, I added Aljoscha in CC who might provide > more information about the topic. > > Best, > Stefan > >> Am 25.09.2017 um 22:59 schrieb Yan Zhou [FDS Science] <yz...@coupang.com>: >> >> Hi, >> >> I am implementing a merge-able trigger, and having a problem in clearing the >> registered timers for a merged window (a window has been merged into the >> merging result). For my implementation, the trigger registers multiple >> timers for each element at Trigger#onElement(). State is used to keep track >> of the registered event time, so that timer can be removed at >> Trigger#clear() later. >> >> However, clearing the registered timers in this way doesn't work if the >> window has been merged. The state of origin window is removed during >> merging. Method AbstractHeapMergingState#mergeNamespaces() removes the state >> of merged window. I think the ContinuousEventTimeTrigger shipped with flink >> would have same issue. >> >> My question is is there a way to keep the state for a merged window? One way >> I can think of is to implement a custom heap state that add the state back >> in AbstractHeapMergingState#mergeState() method. Or is there a way to clear >> the timers without using state? Can I twist the internal timer's source code >> to expose a method to remove all timers for a specified window? >> >> Please advise and thank you for your help. >> >> Best >> Yan >
