From 3483e18d4bdfb4207dd30ddf0a6b0beac570428f Mon Sep 17 00:00:00 2001
From: Michael Quigley <michael@quigley.com>
Date: Wed, 30 Apr 2025 14:47:13 -0400
Subject: [PATCH] batch size in loopers (#953)

---
 canary/looper.go                  |  3 +++
 canary/publicHttpLooper.go        | 12 +++++++++++-
 cmd/zrok/testCanaryPublicProxy.go | 16 ++++++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/canary/looper.go b/canary/looper.go
index b23cdff9..013dbf20 100644
--- a/canary/looper.go
+++ b/canary/looper.go
@@ -16,6 +16,9 @@ type LooperOptions struct {
 	MaxDwell       time.Duration
 	MinPacing      time.Duration
 	MaxPacing      time.Duration
+	BatchSize      uint
+	MinBatchPacing time.Duration
+	MaxBatchPacing time.Duration
 	TargetName     string
 	BindAddress    string
 	SnapshotQueue  chan *Snapshot
diff --git a/canary/publicHttpLooper.go b/canary/publicHttpLooper.go
index 0e0f6603..0200569c 100644
--- a/canary/publicHttpLooper.go
+++ b/canary/publicHttpLooper.go
@@ -168,6 +168,16 @@ func (l *PublicHttpLooper) iterate() {
 	defer func() { l.results.StopTime = time.Now() }()
 
 	for i := uint(0); i < l.opt.Iterations && !l.abort; i++ {
+		if i > 0 && l.opt.BatchSize > 0 && i%l.opt.BatchSize == 0 {
+			batchPacingMs := l.opt.MaxBatchPacing.Milliseconds()
+			batchPacingDelta := l.opt.MaxBatchPacing.Milliseconds() - l.opt.MinBatchPacing.Milliseconds()
+			if batchPacingDelta > 0 {
+				batchPacingMs = (rand.Int63() % batchPacingDelta) + l.opt.MinBatchPacing.Milliseconds()
+			}
+			logrus.Debug("sleeping %d ms for batch pacing", batchPacingMs)
+			time.Sleep(time.Duration(batchPacingMs) * time.Millisecond)
+		}
+
 		snapshot := NewSnapshot("public-proxy", l.id, uint64(i))
 
 		if i > 0 && i%l.opt.StatusInterval == 0 {
@@ -227,8 +237,8 @@ func (l *PublicHttpLooper) iterate() {
 		pacingDelta := l.opt.MaxPacing.Milliseconds() - l.opt.MinPacing.Milliseconds()
 		if pacingDelta > 0 {
 			pacingMs = (rand.Int63() % pacingDelta) + l.opt.MinPacing.Milliseconds()
-			time.Sleep(time.Duration(pacingMs) * time.Millisecond)
 		}
+		time.Sleep(time.Duration(pacingMs) * time.Millisecond)
 
 		l.results.Loops++
 	}
diff --git a/cmd/zrok/testCanaryPublicProxy.go b/cmd/zrok/testCanaryPublicProxy.go
index 190b5222..d8e60c1c 100644
--- a/cmd/zrok/testCanaryPublicProxy.go
+++ b/cmd/zrok/testCanaryPublicProxy.go
@@ -31,6 +31,10 @@ type testCanaryPublicProxy struct {
 	maxDwell          time.Duration
 	minPacing         time.Duration
 	maxPacing         time.Duration
+	batchSize         uint
+	batchPacing       time.Duration
+	minBatchPacing    time.Duration
+	maxBatchPacing    time.Duration
 	frontendSelection string
 	canaryConfig      string
 }
@@ -55,6 +59,10 @@ func newTestCanaryPublicProxy() *testCanaryPublicProxy {
 	cmd.Flags().DurationVar(&command.maxDwell, "max-dwell", 1*time.Second, "Maximum dwell time")
 	cmd.Flags().DurationVar(&command.minPacing, "min-pacing", 0, "Minimum pacing time")
 	cmd.Flags().DurationVar(&command.maxPacing, "max-pacing", 0, "Maximum pacing time")
+	cmd.Flags().UintVar(&command.batchSize, "batch-size", 0, "Iterate in batches of this size")
+	cmd.Flags().DurationVar(&command.batchPacing, "batch-pacing", 0, "Fixed batch pacing time")
+	cmd.Flags().DurationVar(&command.minBatchPacing, "min-batch-pacing", 0, "Minimum batch pacing time")
+	cmd.Flags().DurationVar(&command.maxBatchPacing, "max-batch-pacing", 0, "Maximum batch pacing time")
 	cmd.Flags().StringVar(&command.frontendSelection, "frontend-selection", "public", "Select frontend selection")
 	cmd.Flags().StringVar(&command.canaryConfig, "canary-config", "", "Path to canary configuration file")
 	return command
@@ -105,6 +113,14 @@ func (cmd *testCanaryPublicProxy) run(_ *cobra.Command, _ []string) {
 			MaxDwell:       cmd.maxDwell,
 			MinPacing:      cmd.minPacing,
 			MaxPacing:      cmd.maxPacing,
+			BatchSize:      cmd.batchSize,
+		}
+		if cmd.batchPacing > 0 {
+			looperOpts.MinBatchPacing = cmd.batchPacing
+			looperOpts.MaxBatchPacing = cmd.batchPacing
+		} else {
+			looperOpts.MinBatchPacing = cmd.minBatchPacing
+			looperOpts.MaxBatchPacing = cmd.maxBatchPacing
 		}
 		if sc != nil {
 			looperOpts.SnapshotQueue = sc.InputQueue