ETA calculation based on past hour's progress (moving window)

go/logic/migrator.go

@@ -70,6 +70,8 @@ type Migrator struct {
 	applyEventsQueue chan tableWriteFunc
 
 	handledChangelogStates map[string]bool
+
+	progressHistory *ProgressHistory
 }
 
 func NewMigrator() *Migrator {
@@ -84,6 +86,7 @@ func NewMigrator() *Migrator {
 		copyRowsQueue:          make(chan tableWriteFunc),
 		applyEventsQueue:       make(chan tableWriteFunc, applyEventsQueueBuffer),
 		handledChangelogStates: make(map[string]bool),
+		progressHistory:        NewProgressHistory(),
 	}
 	return migrator
 }
@@ -782,19 +785,18 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	}
 
 	var etaSeconds float64 = math.MaxFloat64
+	this.progressHistory.markState()
 	eta := "N/A"
 	if progressPct >= 100.0 {
 		eta = "due"
-	} else if progressPct >= 1.0 {
+	} else if etaTime := this.progressHistory.getETA(); progressPct >= 0.1 && !etaTime.IsZero() {
-		elapsedRowCopySeconds := this.migrationContext.ElapsedRowCopyTime().Seconds()
+		etaDuration := etaTime.Sub(time.Now())
-		totalExpectedSeconds := elapsedRowCopySeconds * float64(rowsEstimate) / float64(totalRowsCopied)
-		etaSeconds = totalExpectedSeconds - elapsedRowCopySeconds
-		if etaSeconds >= 0 {
-			etaDuration := time.Duration(etaSeconds) * time.Second
 		eta = base.PrettifyDurationOutput(etaDuration)
-		} else {
+		etaSeconds = etaDuration.Seconds()
-			eta = "due"
 	}
+
+	if etaSeconds < 0 {
+		eta = "due"
 	}
 
 	state := "migrating"

go/logic/progress.go

@@ -7,6 +7,7 @@ package logic
 
 import (
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/github/gh-ost/go/base"
@@ -101,5 +102,14 @@ func (this *ProgressHistory) getETA() (eta time.Time) {
 	if !this.hasEnoughData() {
 		return eta
 	}
+
+	oldest := this.oldestState()
+	newest := this.newestState()
+	rowsEstimate := atomic.LoadInt64(&this.migrationContext.RowsEstimate) + atomic.LoadInt64(&this.migrationContext.RowsDeltaEstimate)
+	ratio := float64(rowsEstimate-oldest.rowsCopied) / float64(newest.rowsCopied-oldest.rowsCopied)
+	// ratio is also float64(totaltime-oldest.mark) / float64(newest.mark-oldest.mark)
+	totalTimeNanosecondsFromOldestMark := ratio * float64(newest.mark.Sub(oldest.mark).Nanoseconds())
+	eta = oldest.mark.Add(time.Duration(totalTimeNanosecondsFromOldestMark))
+
 	return eta
 }