It seems to me that watermark hold cannot change it (currently),
because in the current implementation timers fire according to
input watermark, but watermark holds apply to output watermark.
If I didn't miss anything.
Dne 10. 6. 2019 18:15 napsal uživatel Lukasz Cwik
<lc...@google.com> <mailto:lc...@google.com>:
I see. Is there a missing watermark hold for timers less then T2?
On Mon, Jun 10, 2019 at 9:08 AM Jan Lukavský <je...@seznam.cz
<mailto:je...@seznam.cz>> wrote:
Yes, there is no difference between GC and user timers in
this case. I think the problem is simply that when
watermark moves from time T1 to T2, DirectRunner fires
all timers that fire until T2, but that can create new
timers for time between T1 and T2, and these will be
fired later, although should have been fired before T2.
Jan
On 6/10/19 5:48 PM, Kenneth Knowles wrote:
Reading your Jira, I believe this problem will
manifest without the interaction of user timers and
GC. Interesting case. It surrounds whether a runner
makes a timer available or fires it prior to the
bundle being committed.
I have commented elsewhere about this part, quoting
the Jira:
> have experimented with this a little and have not
yet figured out what the correct solution should be.
What I tried:
> 1) hold input watermark for min(setup timers)
> 2) fire timers based not on input watermark, but on
output watermark (output watermark is held by min
timer stamp)
Neither of these quite works. What we need is a
separate "element input watermark" and "timer input
watermark". The overall input watermark that drives
GC is the min of these. The output watermark is also
held to this overall input watermark. User timers
fire according to the element input watermark.
Kenn
On Mon, Jun 10, 2019 at 8:44 AM Lukasz Cwik
<lc...@google.com <mailto:lc...@google.com>> wrote:
Jan are you editing the implementation of how
timers work within the DirectRunner or are trying
to build support for time sorted input on top of
the Beam model for timers?
Because I think you will need to do the former.
On Mon, Jun 10, 2019 at 8:41 AM Jan Lukavský
<je...@seznam.cz <mailto:je...@seznam.cz>> wrote:
Hm, that would probably work, thanks!
But, should the timers behave like that? I'm
trying to fix tris by introducing a sequence
of watermarks
inputs watermark -> timer watermark ->
output watermark
as suggested in the JIRA, and it actually
seems to be working as expected. It even
cleans some code paths, but I'm debugging
some strange behavior this exposed -
`WatermarkHold.watermarkHoldTagForTimestampCombiner`
seems to have stopped clearing itself after
this change and some Pipelines therefore
stopped working. I'm little lost why this
happened. I can push code I have if anyone
interested.
Jan
On 6/10/19 5:32 PM, Lukasz Cwik wrote:
We hit an instance of this problem before
and solved it rescheduling the GC timer
again if there was a conflicting timer
that was also meant to fire.
On Mon, Jun 10, 2019 at 8:17 AM Jan
Lukavský <je...@seznam.cz
<mailto:je...@seznam.cz>> wrote:
For a single key. I'm getting into
collision of timerId
`__StatefulParDoGcTimerId`
(StatefulDoFnRunner) and my timerId
for flushing sorted elements in
implementation of
@RequiresTimeSortedInput. The timers
are being swapped at the end of input
(but it can happen anywhere near end
of window), which results in state
being cleared before it gets flushed,
which means data loss.
Jan
On 6/10/19 5:08 PM, Reuven Lax wrote:
Do you mean for a single key or
across keys?
On Mon, Jun 10, 2019, 5:11 AM Jan
Lukavský <je...@seznam.cz
<mailto:je...@seznam.cz>> wrote:
Hi,
I have come across issue [1],
where I'm not sure how to
solve this in
most elegant way.
Any suggestions?
Thanks,
Jan
[1]
https://issues.apache.org/jira/browse/BEAM-7520
It seems to me that watermark hold cannot change it (currently), because in
the current implementation timers fire according to input watermark, but
watermark holds apply to output watermark. If I didn't miss anything.
Dne 10. 6. 2019 18:15 napsal uživatel Lukasz Cwik<lc...@google.com>
<mailto:lc...@google.com>:
I see. Is there a missing watermark hold for timers less then T2?
On Mon, Jun 10, 2019 at 9:08 AM Jan Lukavský<je...@seznam.cz>
<mailto:je...@seznam.cz> wrote:
Yes, there is no difference between GC and user timers in this case. I
think the problem is simply that when watermark moves from time T1 to T2,
DirectRunner fires all timers that fire until T2, but that can create new
timers for time between T1 and T2, and these will be fired later, although
should have been fired before T2.
Jan
On 6/10/19 5:48 PM, Kenneth Knowles wrote:
Reading your Jira, I believe this problem will manifest without the
interaction of user timers and GC. Interesting case. It surrounds whether a
runner makes a timer available or fires it prior to the bundle being committed.
I have commented elsewhere about this part, quoting the Jira:
have experimented with this a little and have not yet figured out what the
correct solution should be. What I tried:
1) hold input watermark for min(setup timers)
2) fire timers based not on input watermark, but on output watermark
(output watermark is held by min timer stamp)
Neither of these quite works. What we need is a separate "element input watermark"
and "timer input watermark". The overall input watermark that drives GC is the min of
these. The output watermark is also held to this overall input watermark. User timers fire
according to the element input watermark.
Kenn
On Mon, Jun 10, 2019 at 8:44 AM Lukasz Cwik<lc...@google.com>
<mailto:lc...@google.com> wrote:
Jan are you editing the implementation of how timers work within the
DirectRunner or are trying to build support for time sorted input on top of the
Beam model for timers?
Because I think you will need to do the former.
On Mon, Jun 10, 2019 at 8:41 AM Jan Lukavský<je...@seznam.cz>
<mailto:je...@seznam.cz> wrote:
Hm, that would probably work, thanks!
But, should the timers behave like that? I'm trying to fix tris by
introducing a sequence of watermarks
inputs watermark -> timer watermark -> output watermark
as suggested in the JIRA, and it actually seems to be working as expected.
It even cleans some code paths, but I'm debugging some strange behavior this
exposed - `WatermarkHold.watermarkHoldTagForTimestampCombiner` seems to have
stopped clearing itself after this change and some Pipelines therefore stopped
working. I'm little lost why this happened. I can push code I have if anyone
interested.
Jan
On 6/10/19 5:32 PM, Lukasz Cwik wrote:
We hit an instance of this problem before and solved it rescheduling the GC
timer again if there was a conflicting timer that was also meant to fire.
On Mon, Jun 10, 2019 at 8:17 AM Jan Lukavský<je...@seznam.cz>
<mailto:je...@seznam.cz> wrote:
For a single key. I'm getting into collision of timerId
`__StatefulParDoGcTimerId` (StatefulDoFnRunner) and my timerId for flushing
sorted elements in implementation of @RequiresTimeSortedInput. The timers are
being swapped at the end of input (but it can happen anywhere near end of
window), which results in state being cleared before it gets flushed, which
means data loss.
Jan
On 6/10/19 5:08 PM, Reuven Lax wrote:
Do you mean for a single key or across keys?
On Mon, Jun 10, 2019, 5:11 AM Jan Lukavský<je...@seznam.cz>
<mailto:je...@seznam.cz> wrote:
Hi,
I have come across issue [1], where I'm not sure how to solve this in
most elegant way.
Any suggestions?
Thanks,
Jan
[1]https://issues.apache.org/jira/browse/BEAM-7520
