compactor: support finer retention period in compactor.go

compactor/compactor.go

@@ -29,8 +29,7 @@ var (
 )
 
 const (
-	checkCompactionInterval   = 5 * time.Minute
-	executeCompactionInterval = time.Hour
+	checkCompactionInterval = 5 * time.Minute
 
 	ModePeriodic = "periodic"
 	ModeRevision = "revision"
@@ -57,7 +56,7 @@ type RevGetter interface {
 	Rev() int64
 }
 
-func New(mode string, retention int, rg RevGetter, c Compactable) (Compactor, error) {
+func New(mode string, retention time.Duration, rg RevGetter, c Compactable) (Compactor, error) {
 	switch mode {
 	case ModePeriodic:
 		return NewPeriodic(retention, rg, c), nil

compactor/periodic.go

@@ -26,10 +26,10 @@ import (
 )
 
 // Periodic compacts the log by purging revisions older than
-// the configured retention time. Compaction happens hourly.
+// the configured retention time.
 type Periodic struct {
-	clock        clockwork.Clock
-	periodInHour int
+	clock  clockwork.Clock
+	period time.Duration
 
 	rg RevGetter
 	c  Compactable
@@ -38,60 +38,60 @@ type Periodic struct {
 	ctx    context.Context
 	cancel context.CancelFunc
 
-	mu     sync.Mutex
+	// mu protects paused
+	mu     sync.RWMutex
 	paused bool
 }
 
 // NewPeriodic creates a new instance of Periodic compactor that purges
-// the log older than h hours.
-func NewPeriodic(h int, rg RevGetter, c Compactable) *Periodic {
+// the log older than h Duration.
+func NewPeriodic(h time.Duration, rg RevGetter, c Compactable) *Periodic {
 	return &Periodic{
-		clock:        clockwork.NewRealClock(),
-		periodInHour: h,
-		rg:           rg,
-		c:            c,
+		clock:  clockwork.NewRealClock(),
+		period: h,
+		rg:     rg,
+		c:      c,
 	}
 }
 
+// periodDivisor divides Periodic.period in into checkCompactInterval duration
+const periodDivisor = 10
+
 func (t *Periodic) Run() {
 	t.ctx, t.cancel = context.WithCancel(context.Background())
 	t.revs = make([]int64, 0)
 	clock := t.clock
-
+	checkCompactInterval := t.period / time.Duration(periodDivisor)
 	go func() {
 		last := clock.Now()
 		for {
 			t.revs = append(t.revs, t.rg.Rev())
 			select {
 			case <-t.ctx.Done():
 				return
-			case <-clock.After(checkCompactionInterval):
+			case <-clock.After(checkCompactInterval):
 				t.mu.Lock()
 				p := t.paused
 				t.mu.Unlock()
 				if p {
 					continue
 				}
 			}
-
-			if clock.Now().Sub(last) < executeCompactionInterval {
+			if clock.Now().Sub(last) < t.period {
 				continue
 			}
-
-			rev, remaining := t.getRev(t.periodInHour)
+			rev, remaining := t.getRev()
 			if rev < 0 {
 				continue
 			}
-
-			plog.Noticef("Starting auto-compaction at revision %d (retention: %d hours)", rev, t.periodInHour)
+			plog.Noticef("Starting auto-compaction at revision %d (retention: %v)", rev, t.period)
 			_, err := t.c.Compact(t.ctx, &pb.CompactionRequest{Revision: rev})
 			if err == nil || err == mvcc.ErrCompacted {
 				t.revs = remaining
-				last = clock.Now()
 				plog.Noticef("Finished auto-compaction at revision %d", rev)
 			} else {
-				plog.Noticef("Failed auto-compaction at revision %d (%v)", err, rev)
-				plog.Noticef("Retry after %v", checkCompactionInterval)
+				plog.Noticef("Failed auto-compaction at revision %d (%v)", rev, err)
+				plog.Noticef("Retry after %v", checkCompactInterval)
 			}
 		}
 	}()
@@ -113,8 +113,8 @@ func (t *Periodic) Resume() {
 	t.paused = false
 }
 
-func (t *Periodic) getRev(h int) (int64, []int64) {
-	i := len(t.revs) - int(time.Duration(h)*time.Hour/checkCompactionInterval)
+func (t *Periodic) getRev() (int64, []int64) {
+	i := len(t.revs) - periodDivisor
 	if i < 0 {
 		return -1, t.revs
 	}

compactor/periodic_test.go

@@ -26,39 +26,36 @@ import (
 
 func TestPeriodic(t *testing.T) {
 	retentionHours := 2
+	retentionDuration := time.Duration(retentionHours) * time.Hour
 
 	fc := clockwork.NewFakeClock()
 	rg := &fakeRevGetter{testutil.NewRecorderStream(), 0}
 	compactable := &fakeCompactable{testutil.NewRecorderStream()}
 	tb := &Periodic{
-		clock:        fc,
-		periodInHour: retentionHours,
-		rg:           rg,
-		c:            compactable,
+		clock:  fc,
+		period: retentionDuration,
+		rg:     rg,
+		c:      compactable,
 	}
 
 	tb.Run()
 	defer tb.Stop()
-
-	n := int(time.Hour / checkCompactionInterval)
-	// collect 5 hours of revisions
-	for i := 0; i < 5; i++ {
-		// advance one hour, one revision for each interval
-		for j := 0; j < n; j++ {
-			rg.Wait(1)
-			fc.Advance(checkCompactionInterval)
-		}
-
-		// compaction doesn't happen til 2 hours elapses
-		if i+1 < retentionHours {
+	checkCompactInterval := retentionDuration / time.Duration(periodDivisor)
+	n := periodDivisor
+	// simulate 5 hours worth of intervals.
+	for i := 0; i < n/retentionHours*5; i++ {
+		rg.Wait(1)
+		fc.Advance(checkCompactInterval)
+		// compaction doesn't happen til 2 hours elapses.
+		if i < n {
 			continue
 		}
-
+		// after 2 hours, compaction happens at every checkCompactInterval.
 		a, err := compactable.Wait(1)
 		if err != nil {
 			t.Fatal(err)
 		}
-		expectedRevision := int64(1 + (i+1)*n - retentionHours*n)
+		expectedRevision := int64(i + 1 - n)
 		if !reflect.DeepEqual(a[0].Params[0], &pb.CompactionRequest{Revision: expectedRevision}) {
 			t.Errorf("compact request = %v, want %v", a[0].Params[0], &pb.CompactionRequest{Revision: expectedRevision})
 		}
@@ -75,21 +72,23 @@ func TestPeriodicPause(t *testing.T) {
 	fc := clockwork.NewFakeClock()
 	compactable := &fakeCompactable{testutil.NewRecorderStream()}
 	rg := &fakeRevGetter{testutil.NewRecorderStream(), 0}
+	retentionDuration := time.Hour
 	tb := &Periodic{
-		clock:        fc,
-		periodInHour: 1,
-		rg:           rg,
-		c:            compactable,
+		clock:  fc,
+		period: retentionDuration,
+		rg:     rg,
+		c:      compactable,
 	}
 
 	tb.Run()
 	tb.Pause()
 
 	// tb will collect 3 hours of revisions but not compact since paused
-	n := int(time.Hour / checkCompactionInterval)
+	checkCompactInterval := retentionDuration / time.Duration(periodDivisor)
+	n := periodDivisor
 	for i := 0; i < 3*n; i++ {
 		rg.Wait(1)
-		fc.Advance(checkCompactionInterval)
+		fc.Advance(checkCompactInterval)
 	}
 	// tb ends up waiting for the clock
 
@@ -102,14 +101,14 @@ func TestPeriodicPause(t *testing.T) {
 	// tb resumes to being blocked on the clock
 	tb.Resume()
 
-	// unblock clock, will kick off a compaction at hour 3:05
+	// unblock clock, will kick off a compaction at hour 3:06
 	rg.Wait(1)
-	fc.Advance(checkCompactionInterval)
+	fc.Advance(checkCompactInterval)
 	a, err := compactable.Wait(1)
 	if err != nil {
 		t.Fatal(err)
 	}
-	// compact the revision from hour 2:05
+	// compact the revision from hour 2:06
 	wreq := &pb.CompactionRequest{Revision: int64(1 + 2*n + 1)}
 	if !reflect.DeepEqual(a[0].Params[0], wreq) {
 		t.Errorf("compact request = %v, want %v", a[0].Params[0], wreq.Revision)