Allow deeper sleep (#10883)

Allow each crawler operation to sleep up to 10 seconds on very heavily loaded systems.

This will of course make minimum crawler speed less, but should be more effective at stopping.

cmd/data-crawler.go

@@ -775,13 +775,16 @@ func (i *crawlItem) objectPath() string {
 	return path.Join(i.prefix, i.objectName)
 }
 
-// sleepDuration multiplies the duration d by x and sleeps if is more than 100 micro seconds.
+// sleepDuration multiplies the duration d by x
-// sleep is limited to max 1 second.
+// and sleeps if is more than 100 micro seconds.
+// Sleep is limited to max 15 seconds.
 func sleepDuration(d time.Duration, x float64) {
+	const maxWait = 15 * time.Second
+	const minWait = 100 * time.Microsecond
 	// Don't sleep for really small amount of time
-	if d := time.Duration(float64(d) * x); d > time.Microsecond*100 {
+	if d := time.Duration(float64(d) * x); d > minWait {
-		if d > time.Second {
+		if d > maxWait {
-			d = time.Second
+			d = maxWait
 		}
 		time.Sleep(d)
 	}