Question about processElement(...) and onTimer(...) in ProcessFunction

[Yassine MARZOUGUI]

Hi all,

In ProcessFuction, does processElement() still get called on incoming elements when onTimer() is called, or are elements buffered until onTimer() returns?

I am wondering because both processElement() and onTimer() can access and manipulate the state, so if for example state.clear() is called at the end of onTimer() is there a risk that a state update by processElement() that happened during the onTimer() call get cleared? Thank you in advance.

Best,

Yassine

[Fabian Hueske-2]

Hi Yassine,

as far as I know, the processElement() and onTimer() methods are not concurrently called.
This is definitely true for event-time timers (they are triggered by watermarks which are internally handled as records) and I'm pretty sure that the behavior is the same for processing time timers.

@Kostas (in CC) please correct me if I'm wrong here.

Best, Fabian

2017-03-14 8:04 GMT+01:00 Yassine MARZOUGUI <[hidden email]>:

Hi all,

In ProcessFuction, does processElement() still get called on incoming elements when onTimer() is called, or are elements buffered until onTimer() returns?

I am wondering because both processElement() and onTimer() can access and manipulate the state, so if for example state.clear() is called at the end of onTimer() is there a risk that a state update by processElement() that happened during the onTimer() call get cleared? Thank you in advance.

Best,

Yassine

[Yassine MARZOUGUI]

Thank you Fabian for you answer.

Best,

Yassine

On Mar 14, 2017 09:31, "Fabian Hueske" <[hidden email]> wrote:

Hi Yassine,

as far as I know, the processElement() and onTimer() methods are not concurrently called.
This is definitely true for event-time timers (they are triggered by watermarks which are internally handled as records) and I'm pretty sure that the behavior is the same for processing time timers.

@Kostas (in CC) please correct me if I'm wrong here.

Best, Fabian

2017-03-14 8:04 GMT+01:00 Yassine MARZOUGUI <[hidden email]>:

Hi all,

In ProcessFuction, does processElement() still get called on incoming elements when onTimer() is called, or are elements buffered until onTimer() returns?

I am wondering because both processElement() and onTimer() can access and manipulate the state, so if for example state.clear() is called at the end of onTimer() is there a risk that a state update by processElement() that happened during the onTimer() call get cleared? Thank you in advance.

Best,

Yassine