The timer will actually fire and will be removed at the original time, but we don't trigger any action on it. We also remove the tombstone state afterwards.
So we use more memory yes depending on the length and number of timers that were deleted. But it is eventually cleaned up. Gyula Ted Yu <yuzhih...@gmail.com> ezt írta (időpont: 2017. ápr. 21., P, 21:38): > A bit curious: wouldn't using "tombstone" markers constitute some memory > leak (since Timers are not released) ? > > Cheers > > On Fri, Apr 21, 2017 at 12:23 PM, Gyula Fóra <gyf...@apache.org> wrote: > >> Hi! >> >> I thought I would drop my opinion here maybe it is relevant. >> >> We have used the Flink internal timer implementation in many of our >> production applications, this supports the Timer deletion but the deletion >> actually turned out to be a huge performance bottleneck because of the bad >> deletion performance of the Priority queue. >> >> In many of our cases deletion could have been avoided by some more clever >> registration/firing logic and we also ended up completely avoiding deletion >> and instead using "tombstone" markers by setting a flag in the state which >> timers not to fire when they actually trigger. >> >> Gyula >> >> >> >> Aljoscha Krettek <aljos...@apache.org> ezt írta (időpont: 2017. ápr. >> 21., P, 14:47): >> >>> Hi, >>> the reasoning behind the limited user facing API was that we were (are) >>> not sure whether we would be able to support efficient deletion of timers >>> for different ways of storing timers. >>> >>> @Stephan, If I remember correctly you were the strongest advocate for >>> not allowing timer deletion. What’s your thinking on this? There was also a >>> quick discussion on https://issues.apache.org/jira/browse/FLINK-3089 where >>> Xiaogang explained that the (new, not merged) RocksDB based timers would >>> have efficient timer deletion. >>> >>> Best, >>> Aljoscha >>> >>> On 20. Apr 2017, at 11:56, Jagadish Bihani <jagad...@helpshift.com> >>> wrote: >>> >>> Hi >>> >>> I am working on a use case where I want to start a timer for a given >>> event type and when that timer expires it will perform certain action. This >>> can be done using Process Function. >>> >>> But I also want to cancel scheduled timer in case of some other types of >>> events. I also checked the implementation of HeapInternalTimerService which >>> implements InternalTimerService interface has those implementations >>> already. Also SimpleTimerService which overrides TimerService also uses >>> InternalTimerService and simply passes VoidNamespace.INSTANCE. >>> >>> So in a way we are using InternalTimerService interface's >>> implementations everywhere. >>> >>> So what is the reason that ProcessFunction.Context uses TimerService? >>> Any reason 'deleteEventTimeTimer' is not exposed to users? If I want to use >>> the deleteEvent functionality how should I go about it? >>> >>> -- >>> Thanks and Regards, >>> Jagadish Bihani >>> >>> >>> >
