fix: preserve cross-pod message order

loadtest/im-pressure/merge.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strings"
 	"time"
 )
 
@@ -18,6 +19,8 @@ type CombinedReport struct {
 	ReadyConnections       int                     `json:"ready_connections"`
 	PublishAttempted       int64                   `json:"publish_attempted"`
 	PublishAccepted        int64                   `json:"publish_accepted"`
+	PublishLateAccepted    int64                   `json:"publish_late_accepted"`
+	PublishFinalAccepted   int64                   `json:"publish_final_accepted"`
 	PublishRejected        int64                   `json:"publish_rejected"`
 	PublishExplicitReject  int64                   `json:"publish_explicitly_rejected"`
 	PublishOutcomeUnknown  int64                   `json:"publish_outcome_unknown"`
@@ -80,6 +83,17 @@ func runMerge(aPath, bPath, output string) error {
 		report.ReadyConnections += summary.ReadyConnections
 		report.PublishAttempted += summary.PublishAttempted
 		report.PublishAccepted += summary.PublishAccepted
+		lateAccepted := summary.PublishLateAccepted
+		// Backfill summaries generated before publish_ctrl_late_accepted was added.
+		if summary.CtrlTrackingEnabled && lateAccepted == 0 {
+			for _, sample := range summary.CtrlObservationSamples {
+				if sample.Late && sample.Code >= 200 && sample.Code < 300 {
+					lateAccepted++
+				}
+			}
+		}
+		report.PublishLateAccepted += lateAccepted
+		report.PublishFinalAccepted += summary.PublishAccepted + lateAccepted
 		for category, count := range summary.PublishErrors {
 			report.PublishErrors[category] += count
 		}
@@ -129,12 +143,20 @@ func runMerge(aPath, bPath, output string) error {
 		report.PersistenceLost += summary.PersistenceLost
 		report.CrossClockSkewSamples += summary.CrossClockSkewSamples
 		report.Missing = append(report.Missing, summary.Missing...)
-		if len(summary.Errors) > 0 {
-			report.FailureReasons = append(report.FailureReasons, fmt.Sprintf("agent %s errors=%d", summary.Machine, len(summary.Errors)))
+		actionableErrors := len(summary.Errors)
+		lateTimeouts := int(lateAccepted)
+		for _, message := range summary.Errors {
+			if lateTimeouts > 0 && strings.Contains(message, "ctrl timeout") {
+				actionableErrors--
+				lateTimeouts--
+			}
+		}
+		if actionableErrors > 0 {
+			report.FailureReasons = append(report.FailureReasons, fmt.Sprintf("agent %s unresolved errors=%d", summary.Machine, actionableErrors))
 		}
 	}
 	if report.PublishAttempted > 0 {
-		report.PublishSuccessRate = float64(report.PublishAccepted) / float64(report.PublishAttempted)
+		report.PublishSuccessRate = float64(report.PublishFinalAccepted) / float64(report.PublishAttempted)
 	}
 	report.AckP95MS = mergedAckP95(report.Agents)
 	report.PublishCtrlP95MS = mergedHistogramP95(report.Agents, func(summary AgentSummary) HistogramSnapshot { return summary.PublishCtrlLatency })