Mailing-List: contact user-help@flink.apache.org; run by ezmlm
Precedence: bulk
From: Nico Kruber <nico@data-artisans.com>
To: user@flink.apache.org
Cc: Gwenhael Pasquiers <gwenhael.pasquiers@ericsson.com>
Subject: Re: Event-time and first watermark
Date: Thu, 03 Aug 2017 16:29:50 +0200
Message-ID: <25456674.YmTk4gz1t5@nico-work>
Organization: data Artisans
In-Reply-To: <AM4PR0701MB22285425E4072328426EC20AF7B10@AM4PR0701MB2228.eurprd07.prod.outlook.com>
References: <AM4PR0701MB22285425E4072328426EC20AF7B10@AM4PR0701MB2228.eurprd07.prod.outlook.com>
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="nextPart3455282.dCrjDyTSWk"; micalg="pgp-sha1"; protocol="application/pgp-signature"
archived-at: Thu, 03 Aug 2017 14:30:01 -0000

--nextPart3455282.dCrjDyTSWk
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset="UTF-8"

Hi Gwenhael,
"A Watermark(t) declares that event time has reached time t in that stream,=
=20
meaning that there should be no more elements from the stream with a timest=
amp=20
t=E2=80=99 <=3D t (i.e. events with timestamps older or equal to the waterm=
ark)." [1]

Therefore, they should be behind the actual event with timestamp t.

What is it that you want to achieve in the end? What do you want to use the=
=20
watermark for? They are basically a means to defining when an event time wi=
ndow=20
ends.


Nico

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/
event_time.html#event-time-and-watermarks

On Thursday, 3 August 2017 10:24:35 CEST Gwenhael Pasquiers wrote:
> Hi,
>=20
> From my tests it seems that the initial watermark value is Long.MIN_VALUE
> even though my first data passed through the timestamp extractor before
> arriving into my ProcessFunction. It looks like the watermark "lags" behi=
nd
> the data by one message.
>=20
> Is there a way to have a watermark more "up to date" ? Or is the only way=
 to
> compute it myself into my ProcessFunction ?
>=20
> Thanks.


--nextPart3455282.dCrjDyTSWk
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: This is a digitally signed message part.
Content-Transfer-Encoding: 7Bit

-----BEGIN PGP SIGNATURE-----

iF0EABECAB0WIQTIh4KsbsNd3l7wd+cg8nJL2uqeWQUCWYMzXgAKCRAg8nJL2uqe
WdAIAKCcVgM+lwfUDqn4TeGEsy9aI3D+fACguZXNZiuotw1M9r9iJclOumtsE2E=
=ewja
-----END PGP SIGNATURE-----

--nextPart3455282.dCrjDyTSWk--