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Posted to commits@beam.apache.org by lo...@apache.org on 2023/02/20 18:07:48 UTC
[beam] branch prism-elementmanager updated (3461896476e -> 8f626c73629)
This is an automated email from the ASF dual-hosted git repository.
lostluck pushed a change to branch prism-elementmanager
in repository https://gitbox.apache.org/repos/asf/beam.git
discard 3461896476e [prism] Add in element manager
omit a17d3429c6f Doc commment typo.
new 8f626c73629 [prism] Add in element manager
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Summary of changes:
sdks/go/test/integration/primitives/checkpointing.go | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[beam] 01/01: [prism] Add in element manager
Posted by lo...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
lostluck pushed a commit to branch prism-elementmanager
in repository https://gitbox.apache.org/repos/asf/beam.git
commit 8f626c73629e83f186f1d1776107b2221433c88d
Author: Robert Burke <ro...@frantil.com>
AuthorDate: Sun Feb 19 12:37:24 2023 -0800
[prism] Add in element manager
---
.../prism/internal/engine/elementmanager.go | 675 +++++++++++++++++++++
.../prism/internal/engine/elementmanager_test.go | 516 ++++++++++++++++
2 files changed, 1191 insertions(+)
diff --git a/sdks/go/pkg/beam/runners/prism/internal/engine/elementmanager.go b/sdks/go/pkg/beam/runners/prism/internal/engine/elementmanager.go
new file mode 100644
index 00000000000..aeabc81b812
--- /dev/null
+++ b/sdks/go/pkg/beam/runners/prism/internal/engine/elementmanager.go
@@ -0,0 +1,675 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package engine handles the operational components of a runner, to
+// track elements, watermarks, timers, triggers etc
+package engine
+
+import (
+ "bytes"
+ "container/heap"
+ "context"
+ "fmt"
+ "io"
+ "sync"
+
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/mtime"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/window"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/runtime/exec"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/typex"
+ "golang.org/x/exp/slog"
+)
+
+type element struct {
+ window typex.Window
+ timestamp mtime.Time
+ pane typex.PaneInfo
+
+ elmBytes []byte
+}
+
+type elements struct {
+ es []element
+ minTimestamp mtime.Time
+}
+
+type PColInfo struct {
+ GlobalID string
+ WDec exec.WindowDecoder
+ WEnc exec.WindowEncoder
+ EDec func(io.Reader) []byte
+}
+
+// ToData recodes the elements with their approprate windowed value header.
+func (es elements) ToData(info PColInfo) [][]byte {
+ var ret [][]byte
+ for _, e := range es.es {
+ var buf bytes.Buffer
+ exec.EncodeWindowedValueHeader(info.WEnc, []typex.Window{e.window}, e.timestamp, e.pane, &buf)
+ buf.Write(e.elmBytes)
+ ret = append(ret, buf.Bytes())
+ }
+ return ret
+}
+
+// elementHeap orders elements based on their timestamps
+// so we can always find the minimum timestamp of pending elements.
+type elementHeap []element
+
+func (h elementHeap) Len() int { return len(h) }
+func (h elementHeap) Less(i, j int) bool { return h[i].timestamp < h[j].timestamp }
+func (h elementHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
+
+func (h *elementHeap) Push(x any) {
+ // Push and Pop use pointer receivers because they modify the slice's length,
+ // not just its contents.
+ *h = append(*h, x.(element))
+}
+
+func (h *elementHeap) Pop() any {
+ old := *h
+ n := len(old)
+ x := old[n-1]
+ *h = old[0 : n-1]
+ return x
+}
+
+type Config struct {
+ // MaxBundleSize caps the number of elements permitted in a bundle.
+ // 0 or less means this is ignored.
+ MaxBundleSize int
+}
+
+// ElementManager handles elements, watermarks, and related errata to determine
+// if a stage is able to be executed. It is the core execution engine of Prism.
+//
+// Essentially, it needs to track the current watermarks for each PCollection
+// and transform/stage. But it's tricky, since the watermarks for the
+// PCollections are always relative to transforms/stages.
+//
+// Key parts:
+//
+// - The parallel input's PCollection's watermark is relative to committed consumed
+// elements. That is, the input elements consumed by the transform after a successful
+// bundle, can advance the watermark, based on the minimum of their elements.
+// - An output PCollection's watermark is relative to its producing transform,
+// which relates to *all of it's outputs*.
+//
+// This means that a PCollection's watermark is the minimum of all it's consuming transforms.
+//
+// So, the watermark manager needs to track:
+// Pending Elements for each stage, along with their windows and timestamps.
+// Each transform's view of the watermarks for the PCollections.
+//
+// Watermarks are advanced based on consumed input, except if the stage produces residuals.
+type ElementManager struct {
+ config Config
+
+ stages map[string]*stageState // The state for each stage.
+
+ consumers map[string][]string // Map from pcollectionID to stageIDs that consumes them as primary input.
+ sideConsumers map[string][]string // Map from pcollectionID to stageIDs that consumes them as side input.
+
+ pcolParents map[string]string // Map from pcollectionID to stageIDs that produce the pcollection.
+
+ refreshCond sync.Cond // refreshCond protects the following fields with it's lock, and unblocks bundle scheduling.
+ inprogressBundles set[string] // Active bundleIDs
+ watermarkRefreshes set[string] // Scheduled stageID watermark refreshes
+
+ pendingElements sync.WaitGroup // pendingElements counts all unprocessed elements in a job. Jobs with no pending elements terminate successfully.
+}
+
+func NewElementManager(config Config) *ElementManager {
+ return &ElementManager{
+ config: config,
+ stages: map[string]*stageState{},
+ consumers: map[string][]string{},
+ sideConsumers: map[string][]string{},
+ pcolParents: map[string]string{},
+ watermarkRefreshes: set[string]{},
+ inprogressBundles: set[string]{},
+ refreshCond: sync.Cond{L: &sync.Mutex{}},
+ }
+}
+
+// AddStage adds a stage to this element manager, connecting it's PCollections and
+// nodes to the watermark propagation graph.
+func (em *ElementManager) AddStage(ID string, inputIDs, sides, outputIDs []string) {
+ slog.Debug("AddStage", slog.String("ID", ID), slog.Any("inputs", inputIDs), slog.Any("sides", sides), slog.Any("outputs", outputIDs))
+ ss := makeStageState(ID, inputIDs, sides, outputIDs)
+
+ em.stages[ss.ID] = ss
+ for _, outputIDs := range ss.outputIDs {
+ em.pcolParents[outputIDs] = ss.ID
+ }
+ for _, input := range inputIDs {
+ em.consumers[input] = append(em.consumers[input], ss.ID)
+ }
+ for _, side := range ss.sides {
+ em.sideConsumers[side] = append(em.sideConsumers[side], ss.ID)
+ }
+}
+
+// StageAggregates marks the given stage as an aggregation, which
+// means elements will only be processed based on windowing strategies.
+func (em *ElementManager) StageAggregates(ID string) {
+ em.stages[ID].aggregate = true
+}
+
+// Impulse marks and initializes the given stage as an impulse which
+// is a root transform that starts processing.
+func (em *ElementManager) Impulse(stageID string) {
+ stage := em.stages[stageID]
+ newPending := []element{{
+ window: window.GlobalWindow{},
+ timestamp: mtime.MinTimestamp,
+ pane: typex.NoFiringPane(),
+ elmBytes: []byte{0}, // Represents an encoded 0 length byte slice.
+ }}
+
+ consumers := em.consumers[stage.outputIDs[0]]
+ slog.Debug("Impulse", slog.String("stageID", stageID), slog.Any("outputs", stage.outputIDs), slog.Any("consumers", consumers))
+
+ em.pendingElements.Add(len(consumers))
+ for _, sID := range consumers {
+ consumer := em.stages[sID]
+ consumer.AddPending(newPending)
+ }
+ refreshes := stage.updateWatermarks(mtime.MaxTimestamp, mtime.MaxTimestamp, em)
+ em.addRefreshes(refreshes)
+}
+
+type RunBundle struct {
+ StageID string
+ BundleID string
+ Watermark mtime.Time
+}
+
+func (rb RunBundle) LogValue() slog.Value {
+ return slog.GroupValue(
+ slog.String("ID", rb.BundleID),
+ slog.String("stage", rb.StageID),
+ slog.Time("watermark", rb.Watermark.ToTime()))
+}
+
+// Bundles is the core execution loop. It produces a sequences of bundles able to be executed.
+// The returned channel is closed when the context is canceled, or there are no pending elements
+// remaining.
+func (em *ElementManager) Bundles(ctx context.Context, nextBundID func() string) <-chan RunBundle {
+ runStageCh := make(chan RunBundle)
+ ctx, cancelFn := context.WithCancel(ctx)
+ go func() {
+ em.pendingElements.Wait()
+ slog.Info("no more pending elements: terminating pipeline")
+ cancelFn()
+ // Ensure the watermark evaluation goroutine exits.
+ em.refreshCond.Broadcast()
+ }()
+ // Watermark evaluation goroutine.
+ go func() {
+ defer close(runStageCh)
+ for {
+ em.refreshCond.L.Lock()
+ // If there are no watermark refreshes available, we wait until there are.
+ for len(em.watermarkRefreshes) == 0 {
+ // Check to see if we must exit
+ select {
+ case <-ctx.Done():
+ em.refreshCond.L.Unlock()
+ return
+ default:
+ }
+ em.refreshCond.Wait() // until watermarks may have changed.
+ }
+
+ // We know there is some work we can do that may advance the watermarks,
+ // refresh them, and see which stages have advanced.
+ advanced := em.refreshWatermarks()
+
+ // Check each advanced stage, to see if it's able to execute based on the watermark.
+ for stageID := range advanced {
+ ss := em.stages[stageID]
+ watermark, ready := ss.bundleReady(em)
+ if ready {
+ bundleID, ok := ss.startBundle(watermark, nextBundID)
+ if !ok {
+ continue
+ }
+ rb := RunBundle{StageID: stageID, BundleID: bundleID, Watermark: watermark}
+
+ em.inprogressBundles.insert(rb.BundleID)
+ em.refreshCond.L.Unlock()
+
+ select {
+ case <-ctx.Done():
+ return
+ case runStageCh <- rb:
+ }
+ em.refreshCond.L.Lock()
+ }
+ }
+ em.refreshCond.L.Unlock()
+ }
+ }()
+ return runStageCh
+}
+
+// InputForBundle returns pre-allocated data for the given bundle, encoding the elements using
+// the PCollection's coders.
+func (em *ElementManager) InputForBundle(rb RunBundle, info PColInfo) [][]byte {
+ ss := em.stages[rb.StageID]
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+ es := ss.inprogress[rb.BundleID]
+ return es.ToData(info)
+}
+
+// PersistBundle uses the tentative bundle output to update the watermarks for the stage.
+// Each stage has two monotonically increasing watermarks, the input watermark, and the output
+// watermark.
+//
+// MAX(CurrentInputWatermark, MIN(PendingElements, InputPCollectionWatermarks)
+// MAX(CurrentOutputWatermark, MIN(InputWatermark, WatermarkHolds))
+//
+// PersistBundle takes in the stage ID, ID of the bundle associated with the pending
+// input elements, and the committed output elements.
+func (em *ElementManager) PersistBundle(rb RunBundle, col2Coders map[string]PColInfo, d TentativeData, inputInfo PColInfo, residuals [][]byte, estimatedOWM map[string]mtime.Time) {
+ stage := em.stages[rb.StageID]
+ for output, data := range d.Raw {
+ info := col2Coders[output]
+ var newPending []element
+ slog.Debug("PersistBundle: processing output", "bundle", rb, slog.String("output", output))
+ for _, datum := range data {
+ buf := bytes.NewBuffer(datum)
+ if len(datum) == 0 {
+ panic(fmt.Sprintf("zero length data for %v: ", output))
+ }
+ for {
+ var rawBytes bytes.Buffer
+ tee := io.TeeReader(buf, &rawBytes)
+ ws, et, pn, err := exec.DecodeWindowedValueHeader(info.WDec, tee)
+ if err != nil {
+ if err == io.EOF {
+ break
+ }
+ slog.Error("PersistBundle: error decoding watermarks", err, "bundle", rb, slog.String("output", output))
+ panic("error decoding watermarks")
+ }
+ // TODO: Optimize unnecessary copies. This is doubleteeing.
+ elmBytes := info.EDec(tee)
+ for _, w := range ws {
+ newPending = append(newPending,
+ element{
+ window: w,
+ timestamp: et,
+ pane: pn,
+ elmBytes: elmBytes,
+ })
+ }
+ }
+ }
+ consumers := em.consumers[output]
+ slog.Debug("PersistBundle: bundle has downstream consumers.", "bundle", rb, slog.Int("newPending", len(newPending)), "consumers", consumers)
+ for _, sID := range consumers {
+ em.pendingElements.Add(len(newPending))
+ consumer := em.stages[sID]
+ consumer.AddPending(newPending)
+ }
+ }
+
+ // Return unprocessed to this stage's pending
+ var unprocessedElements []element
+ for _, residual := range residuals {
+ buf := bytes.NewBuffer(residual)
+ ws, et, pn, err := exec.DecodeWindowedValueHeader(inputInfo.WDec, buf)
+ if err != nil {
+ if err == io.EOF {
+ break
+ }
+ slog.Error("PersistBundle: error decoding residual header", err, "bundle", rb)
+ panic("error decoding residual header")
+ }
+
+ for _, w := range ws {
+ unprocessedElements = append(unprocessedElements,
+ element{
+ window: w,
+ timestamp: et,
+ pane: pn,
+ elmBytes: buf.Bytes(),
+ })
+ }
+ }
+ // Add unprocessed back to the pending stack.
+ if len(unprocessedElements) > 0 {
+ em.pendingElements.Add(len(unprocessedElements))
+ stage.AddPending(unprocessedElements)
+ }
+ // Clear out the inprogress elements associated with the completed bundle.
+ // Must be done after adding the new pending elements to avoid an incorrect
+ // watermark advancement.
+ stage.mu.Lock()
+ completed := stage.inprogress[rb.BundleID]
+ em.pendingElements.Add(-len(completed.es))
+ delete(stage.inprogress, rb.BundleID)
+ // If there are estimated output watermarks, set the estimated
+ // output watermark for the stage.
+ if len(estimatedOWM) > 0 {
+ estimate := mtime.MaxTimestamp
+ for _, t := range estimatedOWM {
+ estimate = mtime.Min(estimate, t)
+ }
+ stage.estimatedOutput = estimate
+ }
+ stage.mu.Unlock()
+
+ // TODO support state/timer watermark holds.
+ em.addRefreshAndClearBundle(stage.ID, rb.BundleID)
+}
+
+func (em *ElementManager) addRefreshes(stages set[string]) {
+ em.refreshCond.L.Lock()
+ defer em.refreshCond.L.Unlock()
+ em.watermarkRefreshes.merge(stages)
+ em.refreshCond.Broadcast()
+}
+
+func (em *ElementManager) addRefreshAndClearBundle(stageID, bundID string) {
+ em.refreshCond.L.Lock()
+ defer em.refreshCond.L.Unlock()
+ delete(em.inprogressBundles, bundID)
+ em.watermarkRefreshes.insert(stageID)
+ em.refreshCond.Broadcast()
+}
+
+// refreshWatermarks incrementally refreshes the watermarks, and returns the set of stages where the
+// the watermark may have advanced.
+// Must be called while holding em.refreshCond.L
+func (em *ElementManager) refreshWatermarks() set[string] {
+ // Need to have at least one refresh signal.
+ nextUpdates := set[string]{}
+ refreshed := set[string]{}
+ var i int
+ for stageID := range em.watermarkRefreshes {
+ // clear out old one.
+ em.watermarkRefreshes.remove(stageID)
+ ss := em.stages[stageID]
+ refreshed.insert(stageID)
+
+ dummyStateHold := mtime.MaxTimestamp
+
+ refreshes := ss.updateWatermarks(ss.minPendingTimestamp(), dummyStateHold, em)
+ nextUpdates.merge(refreshes)
+ // cap refreshes incrementally.
+ if i < 10 {
+ i++
+ } else {
+ break
+ }
+ }
+ em.watermarkRefreshes.merge(nextUpdates)
+ return refreshed
+}
+
+type set[K comparable] map[K]struct{}
+
+func (s set[K]) remove(k K) {
+ delete(s, k)
+}
+
+func (s set[K]) insert(k K) {
+ s[k] = struct{}{}
+}
+
+func (s set[K]) merge(o set[K]) {
+ for k := range o {
+ s.insert(k)
+ }
+}
+
+// stageState is the internal watermark and input tracking for a stage.
+type stageState struct {
+ ID string
+ inputID string // PCollection ID of the parallel input
+ outputIDs []string // PCollection IDs of outputs to update consumers.
+ sides []string // PCollection IDs of side inputs that can block execution.
+
+ // Special handling bits
+ aggregate bool // whether this state needs to block for aggregation.
+ strat winStrat // Windowing Strategy for aggregation fireings.
+
+ mu sync.Mutex
+ upstreamWatermarks sync.Map // watermark set from inputPCollection's parent.
+ input mtime.Time // input watermark for the parallel input.
+ output mtime.Time // Output watermark for the whole stage
+ estimatedOutput mtime.Time // Estimated watermark output from DoFns
+
+ pending elementHeap // pending input elements for this stage that are to be processesd
+ inprogress map[string]elements // inprogress elements by active bundles, keyed by bundle
+}
+
+// makeStageState produces an initialized stageState.
+func makeStageState(ID string, inputIDs, sides, outputIDs []string) *stageState {
+ ss := &stageState{
+ ID: ID,
+ outputIDs: outputIDs,
+ sides: sides,
+ strat: defaultStrat{},
+
+ input: mtime.MinTimestamp,
+ output: mtime.MinTimestamp,
+ estimatedOutput: mtime.MinTimestamp,
+ }
+
+ // Initialize the upstream watermarks to minTime.
+ for _, pcol := range inputIDs {
+ ss.upstreamWatermarks.Store(pcol, mtime.MinTimestamp)
+ }
+ if len(inputIDs) == 1 {
+ ss.inputID = inputIDs[0]
+ }
+ return ss
+}
+
+// AddPending adds elements to the pending heap.
+func (ss *stageState) AddPending(newPending []element) {
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+ ss.pending = append(ss.pending, newPending...)
+ heap.Init(&ss.pending)
+}
+
+// updateUpstreamWatermark is for the parent of the input pcollection
+// to call, to update downstream stages with it's current watermark.
+// This avoids downstream stages inverting lock orderings from
+// calling their parent stage to get their input pcollection's watermark.
+func (ss *stageState) updateUpstreamWatermark(pcol string, upstream mtime.Time) {
+ // A stage will only have a single upstream watermark, so
+ // we simply set this.
+ ss.upstreamWatermarks.Store(pcol, upstream)
+}
+
+// UpstreamWatermark gets the minimum value of all upstream watermarks.
+func (ss *stageState) UpstreamWatermark() (string, mtime.Time) {
+ upstream := mtime.MaxTimestamp
+ var name string
+ ss.upstreamWatermarks.Range(func(key, val any) bool {
+ // Use <= to ensure if available we get a name.
+ if val.(mtime.Time) <= upstream {
+ upstream = val.(mtime.Time)
+ name = key.(string)
+ }
+ return true
+ })
+ return name, upstream
+}
+
+// InputWatermark gets the current input watermark for the stage.
+func (ss *stageState) InputWatermark() mtime.Time {
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+ return ss.input
+}
+
+// OutputWatermark gets the current output watermark for the stage.
+func (ss *stageState) OutputWatermark() mtime.Time {
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+ return ss.output
+}
+
+// startBundle initializes a bundle with elements if possible.
+// A bundle only starts if there are elements at all, and if it's
+// an aggregation stage, if the windowing stratgy allows it.
+func (ss *stageState) startBundle(watermark mtime.Time, genBundID func() string) (string, bool) {
+ defer func() {
+ if e := recover(); e != nil {
+ panic(fmt.Sprintf("generating bundle for stage %v at %v panicked\n%v", ss.ID, watermark, e))
+ }
+ }()
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+
+ var toProcess, notYet []element
+ for _, e := range ss.pending {
+ if !ss.aggregate || ss.aggregate && ss.strat.EarliestCompletion(e.window) <= watermark {
+ toProcess = append(toProcess, e)
+ } else {
+ notYet = append(notYet, e)
+ }
+ }
+ ss.pending = notYet
+ heap.Init(&ss.pending)
+
+ if len(toProcess) == 0 {
+ return "", false
+ }
+ // Is THIS is where basic splits should happen/per element processing?
+ es := elements{
+ es: toProcess,
+ minTimestamp: toProcess[0].timestamp,
+ }
+ if ss.inprogress == nil {
+ ss.inprogress = make(map[string]elements)
+ }
+ bundID := genBundID()
+ ss.inprogress[bundID] = es
+ return bundID, true
+}
+
+// minimumPendingTimestamp returns the minimum pending timestamp from all pending elements,
+// including in progress ones.
+//
+// Assumes that the pending heap is initialized if it's not empty.
+func (ss *stageState) minPendingTimestamp() mtime.Time {
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+ minPending := mtime.MaxTimestamp
+ if len(ss.pending) != 0 {
+ minPending = ss.pending[0].timestamp
+ }
+ for _, es := range ss.inprogress {
+ minPending = mtime.Min(minPending, es.minTimestamp)
+ }
+ return minPending
+}
+
+func (ss *stageState) String() string {
+ pcol, up := ss.UpstreamWatermark()
+ return fmt.Sprintf("[%v] IN: %v OUT: %v UP: %q %v, aggregation: %v", ss.ID, ss.input, ss.output, pcol, up, ss.aggregate)
+}
+
+// updateWatermarks performs the following operations:
+//
+// Watermark_In' = MAX(Watermark_In, MIN(U(TS_Pending), U(Watermark_InputPCollection)))
+// Watermark_Out' = MAX(Watermark_Out, MIN(Watermark_In', U(StateHold)))
+// Watermark_PCollection = Watermark_Out_ProducingPTransform
+func (ss *stageState) updateWatermarks(minPending, minStateHold mtime.Time, em *ElementManager) set[string] {
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+
+ // PCollection watermarks are based on their parents's output watermark.
+ _, newIn := ss.UpstreamWatermark()
+
+ // Set the input watermark based on the minimum pending elements,
+ // and the current input pcollection watermark.
+ if minPending < newIn {
+ newIn = minPending
+ }
+
+ // If bigger, advance the input watermark.
+ if newIn > ss.input {
+ ss.input = newIn
+ }
+ // The output starts with the new input as the basis.
+ newOut := ss.input
+
+ // If we're given an estimate, and it's further ahead, we use that instead.
+ if ss.estimatedOutput > ss.output {
+ newOut = ss.estimatedOutput
+ }
+
+ // We adjust based on the minimum state hold.
+ if minStateHold < newOut {
+ newOut = minStateHold
+ }
+ refreshes := set[string]{}
+ // If bigger, advance the output watermark
+ if newOut > ss.output {
+ ss.output = newOut
+ for _, outputCol := range ss.outputIDs {
+ consumers := em.consumers[outputCol]
+
+ for _, sID := range consumers {
+ em.stages[sID].updateUpstreamWatermark(outputCol, ss.output)
+ refreshes.insert(sID)
+ }
+ // Inform side input consumers, but don't update the upstream watermark.
+ for _, sID := range em.sideConsumers[outputCol] {
+ refreshes.insert(sID)
+ }
+ }
+ }
+ return refreshes
+}
+
+// bundleReady returns the maximum allowed watermark for this stage, and whether
+// it's permitted to execute by side inputs.
+func (ss *stageState) bundleReady(em *ElementManager) (mtime.Time, bool) {
+ ss.mu.Lock()
+ defer ss.mu.Unlock()
+ // If the upstream watermark and the input watermark are the same,
+ // then we can't yet process this stage.
+ inputW := ss.input
+ _, upstreamW := ss.UpstreamWatermark()
+ if inputW == upstreamW {
+ slog.Debug("bundleReady: insufficient upstream watermark",
+ slog.String("stage", ss.ID),
+ slog.Group("watermark",
+ slog.Any("upstream", upstreamW),
+ slog.Any("input", inputW)))
+ return mtime.MinTimestamp, false
+ }
+ ready := true
+ for _, side := range ss.sides {
+ pID := em.pcolParents[side]
+ parent := em.stages[pID]
+ ow := parent.OutputWatermark()
+ if upstreamW > ow {
+ ready = false
+ }
+ }
+ return upstreamW, ready
+}
diff --git a/sdks/go/pkg/beam/runners/prism/internal/engine/elementmanager_test.go b/sdks/go/pkg/beam/runners/prism/internal/engine/elementmanager_test.go
new file mode 100644
index 00000000000..69f8b73cd90
--- /dev/null
+++ b/sdks/go/pkg/beam/runners/prism/internal/engine/elementmanager_test.go
@@ -0,0 +1,516 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package engine
+
+import (
+ "container/heap"
+ "context"
+ "fmt"
+ "io"
+ "testing"
+
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/coder"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/mtime"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/window"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/runtime/exec"
+ "github.com/apache/beam/sdks/v2/go/pkg/beam/core/typex"
+ "github.com/google/go-cmp/cmp"
+)
+
+func TestElementHeap(t *testing.T) {
+ elements := elementHeap{
+ element{timestamp: mtime.EndOfGlobalWindowTime},
+ element{timestamp: mtime.MaxTimestamp},
+ element{timestamp: 3},
+ element{timestamp: mtime.MinTimestamp},
+ element{timestamp: 2},
+ element{timestamp: mtime.ZeroTimestamp},
+ element{timestamp: 1},
+ }
+ heap.Init(&elements)
+ heap.Push(&elements, element{timestamp: 4})
+
+ if got, want := elements.Len(), len(elements); got != want {
+ t.Errorf("elements.Len() = %v, want %v", got, want)
+ }
+ if got, want := elements[0].timestamp, mtime.MinTimestamp; got != want {
+ t.Errorf("elements[0].timestamp = %v, want %v", got, want)
+ }
+
+ wanted := []mtime.Time{mtime.MinTimestamp, mtime.ZeroTimestamp, 1, 2, 3, 4, mtime.EndOfGlobalWindowTime, mtime.MaxTimestamp}
+ for i, want := range wanted {
+ if got := heap.Pop(&elements).(element).timestamp; got != want {
+ t.Errorf("[%d] heap.Pop(&elements).(element).timestamp = %v, want %v", i, got, want)
+ }
+ }
+}
+
+func TestStageState_minPendingTimestamp(t *testing.T) {
+
+ newState := func() *stageState {
+ return makeStageState("test", []string{"testInput"}, nil, []string{"testOutput"})
+ }
+ t.Run("noElements", func(t *testing.T) {
+ ss := newState()
+ got := ss.minPendingTimestamp()
+ want := mtime.MaxTimestamp
+ if got != want {
+ t.Errorf("ss.minPendingTimestamp() = %v, want %v", got, want)
+ }
+ })
+
+ want := mtime.ZeroTimestamp - 20
+ t.Run("onlyPending", func(t *testing.T) {
+ ss := newState()
+ ss.pending = elementHeap{
+ element{timestamp: mtime.EndOfGlobalWindowTime},
+ element{timestamp: mtime.MaxTimestamp},
+ element{timestamp: 3},
+ element{timestamp: want},
+ element{timestamp: 2},
+ element{timestamp: mtime.ZeroTimestamp},
+ element{timestamp: 1},
+ }
+ heap.Init(&ss.pending)
+
+ got := ss.minPendingTimestamp()
+ if got != want {
+ t.Errorf("ss.minPendingTimestamp() = %v, want %v", got, want)
+ }
+ })
+
+ t.Run("onlyInProgress", func(t *testing.T) {
+ ss := newState()
+ ss.inprogress = map[string]elements{
+ "a": {
+ es: []element{
+ {timestamp: mtime.EndOfGlobalWindowTime},
+ {timestamp: mtime.MaxTimestamp},
+ },
+ minTimestamp: mtime.EndOfGlobalWindowTime,
+ },
+ "b": {
+ es: []element{
+ {timestamp: 3},
+ {timestamp: want},
+ {timestamp: 2},
+ {timestamp: 1},
+ },
+ minTimestamp: want,
+ },
+ "c": {
+ es: []element{
+ {timestamp: mtime.ZeroTimestamp},
+ },
+ minTimestamp: mtime.ZeroTimestamp,
+ },
+ }
+
+ got := ss.minPendingTimestamp()
+ if got != want {
+ t.Errorf("ss.minPendingTimestamp() = %v, want %v", got, want)
+ }
+ })
+
+ t.Run("minInPending", func(t *testing.T) {
+ ss := newState()
+ ss.pending = elementHeap{
+ {timestamp: 3},
+ {timestamp: want},
+ {timestamp: 2},
+ {timestamp: 1},
+ }
+ heap.Init(&ss.pending)
+ ss.inprogress = map[string]elements{
+ "a": {
+ es: []element{
+ {timestamp: mtime.EndOfGlobalWindowTime},
+ {timestamp: mtime.MaxTimestamp},
+ },
+ minTimestamp: mtime.EndOfGlobalWindowTime,
+ },
+ "c": {
+ es: []element{
+ {timestamp: mtime.ZeroTimestamp},
+ },
+ minTimestamp: mtime.ZeroTimestamp,
+ },
+ }
+
+ got := ss.minPendingTimestamp()
+ if got != want {
+ t.Errorf("ss.minPendingTimestamp() = %v, want %v", got, want)
+ }
+ })
+ t.Run("minInProgress", func(t *testing.T) {
+ ss := newState()
+ ss.pending = elementHeap{
+ {timestamp: 3},
+ {timestamp: 2},
+ {timestamp: 1},
+ }
+ heap.Init(&ss.pending)
+ ss.inprogress = map[string]elements{
+ "a": {
+ es: []element{
+ {timestamp: want},
+ {timestamp: mtime.EndOfGlobalWindowTime},
+ {timestamp: mtime.MaxTimestamp},
+ },
+ minTimestamp: want,
+ },
+ "c": {
+ es: []element{
+ {timestamp: mtime.ZeroTimestamp},
+ },
+ minTimestamp: mtime.ZeroTimestamp,
+ },
+ }
+
+ got := ss.minPendingTimestamp()
+ if got != want {
+ t.Errorf("ss.minPendingTimestamp() = %v, want %v", got, want)
+ }
+ })
+}
+
+func TestStageState_getUpstreamWatermark(t *testing.T) {
+ impulse := makeStageState("impulse", nil, nil, []string{"output"})
+ _, up := impulse.UpstreamWatermark()
+ if got, want := up, mtime.MaxTimestamp; got != want {
+ t.Errorf("impulse.getUpstreamWatermark() = %v, want %v", got, want)
+ }
+
+ dofn := makeStageState("dofn", []string{"input"}, nil, []string{"output"})
+ dofn.updateUpstreamWatermark("input", 42)
+
+ _, up = dofn.UpstreamWatermark()
+ if got, want := up, mtime.Time(42); got != want {
+ t.Errorf("dofn.getUpstreamWatermark() = %v, want %v", got, want)
+ }
+
+ flatten := makeStageState("flatten", []string{"a", "b", "c"}, nil, []string{"output"})
+ flatten.updateUpstreamWatermark("a", 50)
+ flatten.updateUpstreamWatermark("b", 42)
+ flatten.updateUpstreamWatermark("c", 101)
+ _, up = flatten.UpstreamWatermark()
+ if got, want := up, mtime.Time(42); got != want {
+ t.Errorf("flatten.getUpstreamWatermark() = %v, want %v", got, want)
+ }
+}
+
+func TestStageState_updateWatermarks(t *testing.T) {
+ inputCol := "testInput"
+ outputCol := "testOutput"
+ newState := func() (*stageState, *stageState, *ElementManager) {
+ underTest := makeStageState("underTest", []string{inputCol}, nil, []string{outputCol})
+ outStage := makeStageState("outStage", []string{outputCol}, nil, nil)
+ em := &ElementManager{
+ consumers: map[string][]string{
+ inputCol: {underTest.ID},
+ outputCol: {outStage.ID},
+ },
+ stages: map[string]*stageState{
+ outStage.ID: outStage,
+ underTest.ID: underTest,
+ },
+ }
+ return underTest, outStage, em
+ }
+
+ tests := []struct {
+ name string
+ initInput, initOutput mtime.Time
+ upstream, minPending, minStateHold mtime.Time
+ wantInput, wantOutput, wantDownstream mtime.Time
+ }{
+ {
+ name: "initialized",
+ initInput: mtime.MinTimestamp,
+ initOutput: mtime.MinTimestamp,
+ upstream: mtime.MinTimestamp,
+ minPending: mtime.EndOfGlobalWindowTime,
+ minStateHold: mtime.EndOfGlobalWindowTime,
+ wantInput: mtime.MinTimestamp, // match default
+ wantOutput: mtime.MinTimestamp, // match upstream
+ wantDownstream: mtime.MinTimestamp, // match upstream
+ }, {
+ name: "upstream",
+ initInput: mtime.MinTimestamp,
+ initOutput: mtime.MinTimestamp,
+ upstream: mtime.ZeroTimestamp,
+ minPending: mtime.EndOfGlobalWindowTime,
+ minStateHold: mtime.EndOfGlobalWindowTime,
+ wantInput: mtime.ZeroTimestamp, // match upstream
+ wantOutput: mtime.ZeroTimestamp, // match upstream
+ wantDownstream: mtime.ZeroTimestamp, // match upstream
+ }, {
+ name: "useMinPending",
+ initInput: mtime.MinTimestamp,
+ initOutput: mtime.MinTimestamp,
+ upstream: mtime.ZeroTimestamp,
+ minPending: -20,
+ minStateHold: mtime.EndOfGlobalWindowTime,
+ wantInput: -20, // match minPending
+ wantOutput: -20, // match minPending
+ wantDownstream: -20, // match minPending
+ }, {
+ name: "useStateHold",
+ initInput: mtime.MinTimestamp,
+ initOutput: mtime.MinTimestamp,
+ upstream: mtime.ZeroTimestamp,
+ minPending: -20,
+ minStateHold: -30,
+ wantInput: -20, // match minPending
+ wantOutput: -30, // match state hold
+ wantDownstream: -30, // match state hold
+ }, {
+ name: "noAdvance",
+ initInput: 20,
+ initOutput: 30,
+ upstream: mtime.MinTimestamp,
+ wantInput: 20, // match original input
+ wantOutput: 30, // match original output
+ wantDownstream: mtime.MinTimestamp, // not propagated
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ ss, outStage, em := newState()
+ ss.input = test.initInput
+ ss.output = test.initOutput
+ ss.updateUpstreamWatermark(inputCol, test.upstream)
+ ss.updateWatermarks(test.minPending, test.minStateHold, em)
+ if got, want := ss.input, test.wantInput; got != want {
+ pcol, up := ss.UpstreamWatermark()
+ t.Errorf("ss.updateWatermarks(%v,%v); ss.input = %v, want %v (upstream %v %v)", test.minPending, test.minStateHold, got, want, pcol, up)
+ }
+ if got, want := ss.output, test.wantOutput; got != want {
+ pcol, up := ss.UpstreamWatermark()
+ t.Errorf("ss.updateWatermarks(%v,%v); ss.output = %v, want %v (upstream %v %v)", test.minPending, test.minStateHold, got, want, pcol, up)
+ }
+ _, up := outStage.UpstreamWatermark()
+ if got, want := up, test.wantDownstream; got != want {
+ t.Errorf("outStage.getUpstreamWatermark() = %v, want %v", got, want)
+ }
+ })
+ }
+
+}
+
+func TestElementManager(t *testing.T) {
+ t.Run("impulse", func(t *testing.T) {
+ em := NewElementManager(Config{})
+ em.AddStage("impulse", nil, nil, []string{"output"})
+ em.AddStage("dofn", []string{"output"}, nil, nil)
+
+ em.Impulse("impulse")
+
+ if got, want := em.stages["impulse"].OutputWatermark(), mtime.MaxTimestamp; got != want {
+ t.Fatalf("impulse.OutputWatermark() = %v, want %v", got, want)
+ }
+
+ var i int
+ ch := em.Bundles(context.Background(), func() string {
+ defer func() { i++ }()
+ return fmt.Sprintf("%v", i)
+ })
+ rb, ok := <-ch
+ if !ok {
+ t.Error("Bundles channel unexpectedly closed")
+ }
+ if got, want := rb.StageID, "dofn"; got != want {
+ t.Errorf("stage to execute = %v, want %v", got, want)
+ }
+ em.PersistBundle(rb, nil, TentativeData{}, PColInfo{}, nil, nil)
+ _, ok = <-ch
+ if ok {
+ t.Error("Bundles channel expected to be closed")
+ }
+ if got, want := i, 1; got != want {
+ t.Errorf("got %v bundles, want %v", got, want)
+ }
+ })
+
+ info := PColInfo{
+ GlobalID: "generic_info", // GlobalID isn't used except for debugging.
+ WDec: exec.MakeWindowDecoder(coder.NewGlobalWindow()),
+ WEnc: exec.MakeWindowEncoder(coder.NewGlobalWindow()),
+ EDec: func(r io.Reader) []byte {
+ b, err := io.ReadAll(r)
+ if err != nil {
+ t.Fatalf("error decoding \"generic_info\" data:%v", err)
+ }
+ return b
+ },
+ }
+ es := elements{
+ es: []element{{
+ window: window.GlobalWindow{},
+ timestamp: mtime.MinTimestamp,
+ pane: typex.NoFiringPane(),
+ elmBytes: []byte{3, 65, 66, 67}, // "ABC"
+ }},
+ minTimestamp: mtime.MinTimestamp,
+ }
+
+ t.Run("dofn", func(t *testing.T) {
+ em := NewElementManager(Config{})
+ em.AddStage("impulse", nil, nil, []string{"input"})
+ em.AddStage("dofn1", []string{"input"}, nil, []string{"output"})
+ em.AddStage("dofn2", []string{"output"}, nil, nil)
+ em.Impulse("impulse")
+
+ var i int
+ ch := em.Bundles(context.Background(), func() string {
+ defer func() { i++ }()
+ t.Log("generating bundle", i)
+ return fmt.Sprintf("%v", i)
+ })
+ rb, ok := <-ch
+ if !ok {
+ t.Error("Bundles channel unexpectedly closed")
+ }
+ t.Log("received bundle", i)
+
+ td := TentativeData{}
+ for _, d := range es.ToData(info) {
+ td.WriteData("output", d)
+ }
+ outputCoders := map[string]PColInfo{
+ "output": info,
+ }
+
+ em.PersistBundle(rb, outputCoders, td, info, nil, nil)
+ rb, ok = <-ch
+ if !ok {
+ t.Error("Bundles channel not expected to be closed")
+ }
+ // Check the data is what's expected:
+ data := em.InputForBundle(rb, info)
+ if got, want := len(data), 1; got != want {
+ t.Errorf("data len = %v, want %v", got, want)
+ }
+ if !cmp.Equal([]byte{127, 223, 59, 100, 90, 28, 172, 9, 0, 0, 0, 1, 15, 3, 65, 66, 67}, data[0]) {
+ t.Errorf("unexpected data, got %v", data[0])
+ }
+ em.PersistBundle(rb, outputCoders, TentativeData{}, info, nil, nil)
+ rb, ok = <-ch
+ if ok {
+ t.Error("Bundles channel expected to be closed", rb)
+ }
+
+ if got, want := i, 2; got != want {
+ t.Errorf("got %v bundles, want %v", got, want)
+ }
+ })
+
+ t.Run("side", func(t *testing.T) {
+ em := NewElementManager(Config{})
+ em.AddStage("impulse", nil, nil, []string{"input"})
+ em.AddStage("dofn1", []string{"input"}, nil, []string{"output"})
+ em.AddStage("dofn2", []string{"input"}, []string{"output"}, nil)
+ em.Impulse("impulse")
+
+ var i int
+ ch := em.Bundles(context.Background(), func() string {
+ defer func() { i++ }()
+ t.Log("generating bundle", i)
+ return fmt.Sprintf("%v", i)
+ })
+ rb, ok := <-ch
+ if !ok {
+ t.Error("Bundles channel unexpectedly closed")
+ }
+ t.Log("received bundle", i)
+
+ if got, want := rb.StageID, "dofn1"; got != want {
+ t.Fatalf("stage to execute = %v, want %v", got, want)
+ }
+
+ td := TentativeData{}
+ for _, d := range es.ToData(info) {
+ td.WriteData("output", d)
+ }
+ outputCoders := map[string]PColInfo{
+ "output": info,
+ "input": info,
+ "impulse": info,
+ }
+
+ em.PersistBundle(rb, outputCoders, td, info, nil, nil)
+ rb, ok = <-ch
+ if !ok {
+ t.Fatal("Bundles channel not expected to be closed")
+ }
+ if got, want := rb.StageID, "dofn2"; got != want {
+ t.Fatalf("stage to execute = %v, want %v", got, want)
+ }
+ em.PersistBundle(rb, outputCoders, TentativeData{}, info, nil, nil)
+ rb, ok = <-ch
+ if ok {
+ t.Error("Bundles channel expected to be closed")
+ }
+
+ if got, want := i, 2; got != want {
+ t.Errorf("got %v bundles, want %v", got, want)
+ }
+ })
+ t.Run("residual", func(t *testing.T) {
+ em := NewElementManager(Config{})
+ em.AddStage("impulse", nil, nil, []string{"input"})
+ em.AddStage("dofn", []string{"input"}, nil, nil)
+ em.Impulse("impulse")
+
+ var i int
+ ch := em.Bundles(context.Background(), func() string {
+ defer func() { i++ }()
+ t.Log("generating bundle", i)
+ return fmt.Sprintf("%v", i)
+ })
+ rb, ok := <-ch
+ if !ok {
+ t.Error("Bundles channel unexpectedly closed")
+ }
+ t.Log("received bundle", i)
+
+ // Add a residual
+ resid := es.ToData(info)
+ em.PersistBundle(rb, nil, TentativeData{}, info, resid, nil)
+ rb, ok = <-ch
+ if !ok {
+ t.Error("Bundles channel not expected to be closed")
+ }
+ // Check the data is what's expected:
+ data := em.InputForBundle(rb, info)
+ if got, want := len(data), 1; got != want {
+ t.Errorf("data len = %v, want %v", got, want)
+ }
+ if !cmp.Equal([]byte{127, 223, 59, 100, 90, 28, 172, 9, 0, 0, 0, 1, 15, 3, 65, 66, 67}, data[0]) {
+ t.Errorf("unexpected data, got %v", data[0])
+ }
+ em.PersistBundle(rb, nil, TentativeData{}, info, nil, nil)
+ rb, ok = <-ch
+ if ok {
+ t.Error("Bundles channel expected to be closed", rb)
+ }
+
+ if got, want := i, 2; got != want {
+ t.Errorf("got %v bundles, want %v", got, want)
+ }
+ })
+}