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https://issues.apache.org/jira/browse/KAFKA-8924?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Michał updated KAFKA-8924:
--------------------------
Description:
h2. Problem
The default creation of TimeWindows, like
{code}
TimeWindows.of(ofMillis(xxx))
{code}
calls an internal constructor
{code}
return new TimeWindows(sizeMs, sizeMs, -1, DEFAULT_RETENTION_MS);
{code}
And the *-1* parameter is the default grace period which I think is here for
backward compatibility
{code}
@SuppressWarnings("deprecation") // continuing to support
Windows#maintainMs/segmentInterval in fallback mode
@Override
public long gracePeriodMs() {
// NOTE: in the future, when we remove maintainMs,
// we should default the grace period to 24h to maintain the default
behavior,
// or we can default to (24h - size) if you want to be super accurate.
return graceMs != -1 ? graceMs : maintainMs() - size();
}
{code}
The problem is that if you use a TimeWindows with gracePeriod of *-1* together
with suppress *untilWindowCloses*, it never emits an event.
You can check the Suppress tests
(SuppressScenarioTest.shouldSupportFinalResultsForTimeWindows), where
[~vvcephei] was (maybe) aware of that and all the scenarios specify the
gracePeriod.
I will add a test without it on my branch and it will fail.
The test:
https://github.com/atais/kafka/commit/221a04dc40d636ffe93a0ad95dfc6bcad653f4db
h2. Now what can be done
One easy fix would be to change the default value to 0, which works fine for me
in my project, however, I am not aware of the impact it would have done due to
the changes in the *gracePeriodMs* method mentioned before.
was:
h2. Problem
The default creation of TimeWindows, like
{code}
TimeWindows.of(ofMillis(xxx))
{code}
calls an internal constructor
{code}
return new TimeWindows(sizeMs, sizeMs, -1, DEFAULT_RETENTION_MS);
{code}
And the *-1* parameter is the default grace period which I think is here for
backward compatibility
{code}
@SuppressWarnings("deprecation") // continuing to support
Windows#maintainMs/segmentInterval in fallback mode
@Override
public long gracePeriodMs() {
// NOTE: in the future, when we remove maintainMs,
// we should default the grace period to 24h to maintain the default
behavior,
// or we can default to (24h - size) if you want to be super accurate.
return graceMs != -1 ? graceMs : maintainMs() - size();
}
{code}
The problem is that if you use a TimeWindows with gracePeriod of *-1* together
with suppress *untilWindowCloses*, it never emits an event.
You can check the Suppress tests
(SuppressScenarioTest.shouldSupportFinalResultsForTimeWindows), where
[~vvcephei] was (maybe) aware of that and all the scenarios specify the
gracePeriod.
I will add a test without it on my branch and it will fail.
h2. Now what can be done
One easy fix would be to change the default value to 0, which works fine for me
in my project, however, I am not aware of the impact it would have done due to
the changes in the *gracePeriodMs* method mentioned before.
> Default grace period (-1) of TimeWindows causes suppress to never emit events
> ------------------------------------------------------------------------------
>
> Key: KAFKA-8924
> URL: https://issues.apache.org/jira/browse/KAFKA-8924
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Affects Versions: 2.3.0
> Reporter: Michał
> Priority: Major
>
> h2. Problem
> The default creation of TimeWindows, like
> {code}
> TimeWindows.of(ofMillis(xxx))
> {code}
> calls an internal constructor
> {code}
> return new TimeWindows(sizeMs, sizeMs, -1, DEFAULT_RETENTION_MS);
> {code}
> And the *-1* parameter is the default grace period which I think is here for
> backward compatibility
> {code}
> @SuppressWarnings("deprecation") // continuing to support
> Windows#maintainMs/segmentInterval in fallback mode
> @Override
> public long gracePeriodMs() {
> // NOTE: in the future, when we remove maintainMs,
> // we should default the grace period to 24h to maintain the default
> behavior,
> // or we can default to (24h - size) if you want to be super accurate.
> return graceMs != -1 ? graceMs : maintainMs() - size();
> }
> {code}
> The problem is that if you use a TimeWindows with gracePeriod of *-1*
> together with suppress *untilWindowCloses*, it never emits an event.
> You can check the Suppress tests
> (SuppressScenarioTest.shouldSupportFinalResultsForTimeWindows), where
> [~vvcephei] was (maybe) aware of that and all the scenarios specify the
> gracePeriod.
> I will add a test without it on my branch and it will fail.
> The test:
> https://github.com/atais/kafka/commit/221a04dc40d636ffe93a0ad95dfc6bcad653f4db
>
> h2. Now what can be done
> One easy fix would be to change the default value to 0, which works fine for
> me in my project, however, I am not aware of the impact it would have done
> due to the changes in the *gracePeriodMs* method mentioned before.
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