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Posted to github@beam.apache.org by GitBox <gi...@apache.org> on 2021/08/31 22:44:24 UTC
[GitHub] [beam] lostluck commented on a change in pull request #15430: [BEAM-3304] Helper functions for triggers
lostluck commented on a change in pull request #15430:
URL: https://github.com/apache/beam/pull/15430#discussion_r699718391
##########
File path: sdks/go/pkg/beam/core/graph/window/trigger.go
##########
@@ -35,3 +35,38 @@ const (
NeverTrigger string = "Trigger_Never_"
AfterSynchronizedProcessingTimeTrigger string = "Trigger_AfterSynchronizedProcessingTime_"
)
+
+// TriggerDefault constructs a default trigger that fires after the end of window.
+// No provision for late arriving data.
Review comment:
Does this mean it discards late data, or is it unspecified? Does that mean it fires once?
##########
File path: sdks/go/test/integration/primitives/windowinto.go
##########
@@ -121,7 +128,21 @@ func TriggerAlways(s beam.Scope) {
col := teststream.Create(s, con)
windowSize := 10 * time.Second
- validate(s.Scope("Fixed"), window.NewFixedWindows(windowSize), col, window.Trigger{Kind: window.AlwaysTrigger}, window.Discarding, 1.0, 2.0, 3.0)
+ validateEquals(s.Scope("Fixed"), window.NewFixedWindows(windowSize), col, window.TriggerAlways(), window.Discarding, 1.0, 2.0, 3.0)
+}
+
+func validateCount(s beam.Scope, wfn *window.Fn, in beam.PCollection, tr window.Trigger, m window.AccumulationMode, expected int) {
+ var accumulationMode beam.AccumulationMode
+ switch m {
+ case window.Accumulating:
+ accumulationMode = beam.PanesAccumulate()
+ case window.Discarding:
+ accumulationMode = beam.PanesDiscard()
+ }
Review comment:
Same comment here.
##########
File path: sdks/go/test/integration/primitives/windowinto.go
##########
@@ -110,7 +117,7 @@ func TriggerDefault(s beam.Scope) {
col := teststream.Create(s, con)
windowSize := 10 * time.Second
- validate(s.Scope("Fixed"), window.NewFixedWindows(windowSize), col, window.Trigger{Kind: window.DefaultTrigger}, window.Accumulating, 6.0, 9.0)
+ validateEquals(s.Scope("Fixed"), window.NewFixedWindows(windowSize), col, window.TriggerDefault(), window.Discarding, 6.0, 9.0)
Review comment:
Why did the accumulation mode change from Accumulating to Discarding here?
##########
File path: sdks/go/test/integration/primitives/windowinto.go
##########
@@ -93,8 +93,15 @@ func WindowSums_Lifted(s beam.Scope) {
WindowSums(s.Scope("Lifted"), stats.SumPerKey)
}
-func validate(s beam.Scope, wfn *window.Fn, in beam.PCollection, tr window.Trigger, m window.AccumulationMode, expected ...interface{}) {
- windowed := beam.WindowInto(s, wfn, in, beam.WindowTrigger{Name: tr}, beam.AccumulationMode{Mode: m})
+func validateEquals(s beam.Scope, wfn *window.Fn, in beam.PCollection, tr window.Trigger, m window.AccumulationMode, expected ...interface{}) {
+ var accumulationMode beam.AccumulationMode
+ switch m {
+ case window.Accumulating:
+ accumulationMode = beam.PanesAccumulate()
+ case window.Discarding:
+ accumulationMode = beam.PanesDiscard()
+ }
Review comment:
Consider instead changing `m` to be `beam.AccumulationMode` and just passing in the argument as before, rather than delegating to a switch, etc.
##########
File path: sdks/go/pkg/beam/core/graph/window/trigger.go
##########
@@ -35,3 +35,38 @@ const (
NeverTrigger string = "Trigger_Never_"
AfterSynchronizedProcessingTimeTrigger string = "Trigger_AfterSynchronizedProcessingTime_"
)
+
+// TriggerDefault constructs a default trigger that fires after the end of window.
+// No provision for late arriving data.
+func TriggerDefault() Trigger {
+ return Trigger{Kind: DefaultTrigger}
+}
+
+// TriggerAlways constructs an always trigger that keeps firing immediately after an element is processed.
+func TriggerAlways() Trigger {
+ return Trigger{Kind: AlwaysTrigger}
+}
+
+// TriggerAfterCount constructs an element count trigger that fires after atleast `count` number of elements are processed.
+func TriggerAfterCount(count int32) Trigger {
+ return Trigger{Kind: ElementCountTrigger, ElementCount: count}
+}
+
+// TriggerAfterProcessingTime constructs a after processing time trigger that fires after 'delay' milliseconds of processing time has passed.
Review comment:
```suggestion
// TriggerAfterProcessingTime constructs an after processing time trigger that fires after 'delay' milliseconds of processing time have passed.
```
##########
File path: sdks/go/pkg/beam/core/graph/window/trigger.go
##########
@@ -35,3 +35,38 @@ const (
NeverTrigger string = "Trigger_Never_"
AfterSynchronizedProcessingTimeTrigger string = "Trigger_AfterSynchronizedProcessingTime_"
)
+
+// TriggerDefault constructs a default trigger that fires after the end of window.
+// No provision for late arriving data.
+func TriggerDefault() Trigger {
+ return Trigger{Kind: DefaultTrigger}
+}
+
+// TriggerAlways constructs an always trigger that keeps firing immediately after an element is processed.
Review comment:
Consider clarifying that this is equivalent to `TriggerRepeat(TriggerAfterCount(1))`. Does anything change here WRT late data or not?
##########
File path: sdks/go/pkg/beam/core/graph/window/trigger.go
##########
@@ -35,3 +35,38 @@ const (
NeverTrigger string = "Trigger_Never_"
AfterSynchronizedProcessingTimeTrigger string = "Trigger_AfterSynchronizedProcessingTime_"
)
+
+// TriggerDefault constructs a default trigger that fires after the end of window.
+// No provision for late arriving data.
+func TriggerDefault() Trigger {
+ return Trigger{Kind: DefaultTrigger}
+}
+
+// TriggerAlways constructs an always trigger that keeps firing immediately after an element is processed.
+func TriggerAlways() Trigger {
+ return Trigger{Kind: AlwaysTrigger}
+}
+
+// TriggerAfterCount constructs an element count trigger that fires after atleast `count` number of elements are processed.
+func TriggerAfterCount(count int32) Trigger {
+ return Trigger{Kind: ElementCountTrigger, ElementCount: count}
+}
+
+// TriggerAfterProcessingTime constructs a after processing time trigger that fires after 'delay' milliseconds of processing time has passed.
+func TriggerAfterProcessingTime(delay int64) Trigger {
+ return Trigger{Kind: AfterProcessingTimeTrigger, Delay: delay}
+}
+
+// TriggerRepeat constructs a repeat trigger that fires a trigger repeatedly once the condition has been met.
+// Ex: window.TriggerRepeat(window.TriggerAfterCount(1)) is same as window.TriggerAlways().
+func TriggerRepeat(tr Trigger) Trigger {
+ return Trigger{Kind: RepeatTrigger, SubTriggers: []Trigger{tr}}
+}
+
+// TriggerAfterEndOfWindow constructs an end of window trigger that is configurable for early firing trigger(before the end of window)
+// and late firing trigger(after the end of window).
+// As of now, the values of Early firing is set to TriggerDefault and Late firing is set to TriggerAlways.
+func TriggerAfterEndOfWindow() Trigger {
+ // TODO(BEAM-3304): modify it to take parameters for early and late firing trigger
+ return Trigger{Kind: AfterEndOfWindowTrigger}
+}
Review comment:
If we're going to change the parameters we shouldn't be putting this in yet. Adding parameters is a breaking incompatible change to users. We could however, have this explicit behavior and call the method: `TriggerAfterEndOfWindowAlways()`, so that way we can maintain the behavior for any users, and can later add the more general `TriggerAfterEndOfWindow()` function that takes parameters.
Separately, the proposed configuration, does it mean that there won't be any early firings?
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