你读一下 EvictingWindowOperator 相关代码或者说 Evictor#evictBefore 的调用链，里面关于 window
state 的处理是比较 hack 的，用文字说也起不到简练的作用
private void emitWindowContents(W window, Iterable>
contents, ListState> windowState) throws Exception {
timestampedCollector.setAbsoluteTimestamp(window.maxTimestamp());
// Work around type system restrictions...
FluentIterable> recordsWithTimestamp = FluentIterable
.from(contents)
.transform(new Function, TimestampedValue>() {
@Override
public TimestampedValue apply(StreamRecord input) {
return TimestampedValue.from(input);
}
});
evictorContext.evictBefore(recordsWithTimestamp,
Iterables.size(recordsWithTimestamp));
FluentIterable projectedContents = recordsWithTimestamp
.transform(new Function, IN>() {
@Override
public IN apply(TimestampedValue input) {
return input.getValue();
}
});
processContext.window = triggerContext.window;
userFunction.process(triggerContext.key, triggerContext.window,
processContext, projectedContents, timestampedCollector);
evictorContext.evictAfter(recordsWithTimestamp,
Iterables.size(recordsWithTimestamp));
//work around to fix FLINK-4369, remove the evicted elements from
the windowState.
//this is inefficient, but there is no other way to remove elements
from ListState, which is an AppendingState.
windowState.clear();
for (TimestampedValue record : recordsWithTimestamp) {
windowState.add(record.getStreamRecord());
}
}
Best,
tison.
USERNAME 于2020年1月21日周二 下午8:25写道：
> evict 丢弃掉的数据，在内存或者RocksDB中也会同步删除吗？
>
>
>
>
>
>
> 在 2020-01-21 17:27:38，"tison" 写道：
> >正好看到这一部分，还是有的，你考虑下滑动的计数窗口
> >
> >[1] 会在 fire 之后把整个 windowState 丢掉，[2] 其实会重新计算 evict 之后的 windowState
> >
> >Best,
> >tison.
> >
> >
> >USERNAME 于2020年1月21日周二 下午5:21写道：
> >
> >> 大家，新年快乐~
> >>
> >>
> >> [1] TriggerResult.FIRE_AND_PURGE
> >>
> >>
> https://github.com/apache/flink/blob/1662d5d0cda6a813e5c59014acfd7615b153119f/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/windowing/evictors/CountEvictor.java#L74
> >> [2] CountEvictor
> >>
> >>
> https://github.com/apache/flink/blob/1662d5d0cda6a813e5c59014acfd7615b153119f/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/WindowOperator.java#L377
> >>
> >>
>
