1 files changed, 118 insertions, 18 deletions
diff --git a/weed/shell/command_volume_fix_replication.go b/weed/shell/command_volume_fix_replication.go
index 210f4819d..4e1a6078b 100644
--- a/weed/shell/command_volume_fix_replication.go
+++ b/weed/shell/command_volume_fix_replication.go
@@ -145,31 +145,131 @@ func keepDataNodesSorted(dataNodes []location) {
 	})
 }
 
+/*
+  if on an existing data node {
+    return false
+  }
+  if different from existing dcs {
+    if lack on different dcs {
+      return true
+    }else{
+      return false
+    }
+  }
+  if not on primary dc {
+    return false
+  }
+  if different from existing racks {
+    if lack on different racks {
+      return true
+    }else{
+      return false
+    }
+  }
+  if not on primary rack {
+    return false
+  }
+  if lacks on same rack {
+    return true
+  } else {
+    return false
+  }
+*/
 func satisfyReplicaPlacement(replicaPlacement *super_block.ReplicaPlacement, existingLocations []location, possibleLocation location) bool {
 
-	existingDataCenters := make(map[string]bool)
-	existingRacks := make(map[string]bool)
-	existingDataNodes := make(map[string]bool)
+	existingDataNodes := make(map[string]int)
 	for _, loc := range existingLocations {
-		existingDataCenters[loc.DataCenter()] = true
-		existingRacks[loc.Rack()] = true
-		existingDataNodes[loc.String()] = true
+		existingDataNodes[loc.String()] += 1
+	}
+	sameDataNodeCount := existingDataNodes[possibleLocation.String()]
+	// avoid duplicated volume on the same data node
+	if sameDataNodeCount > 0 {
+		return false
+	}
+
+	existingDataCenters := make(map[string]int)
+	for _, loc := range existingLocations {
+		existingDataCenters[loc.DataCenter()] += 1
+	}
+	primaryDataCenters, _ := findTopKeys(existingDataCenters)
+
+	// ensure data center count is within limit
+	if _, found := existingDataCenters[possibleLocation.DataCenter()]; !found {
+		// different from existing dcs
+		if len(existingDataCenters) < replicaPlacement.DiffDataCenterCount+1 {
+			// lack on different dcs
+			return true
+		} else {
+			// adding this would go over the different dcs limit
+			return false
+		}
+	}
+	// now this is same as one of the existing data center
+	if !isAmong(possibleLocation.DataCenter(), primaryDataCenters) {
+		// not on one of the primary dcs
+		return false
 	}
 
-	if replicaPlacement.DiffDataCenterCount >= len(existingDataCenters) {
-		// check dc, good if different from any existing data centers
-		_, found := existingDataCenters[possibleLocation.DataCenter()]
-		return !found
-	} else if replicaPlacement.DiffRackCount >= len(existingRacks) {
-		// check rack, good if different from any existing racks
-		_, found := existingRacks[possibleLocation.Rack()]
-		return !found
-	} else if replicaPlacement.SameRackCount >= len(existingDataNodes) {
-		// check data node, good if different from any existing data nodes
-		_, found := existingDataNodes[possibleLocation.String()]
-		return !found
+	// now this is one of the primary dcs
+	existingRacks := make(map[string]int)
+	for _, loc := range existingLocations {
+		if loc.DataCenter()!=possibleLocation.DataCenter() {
+			continue
+		}
+		existingRacks[loc.Rack()] += 1
+	}
+	primaryRacks, _ := findTopKeys(existingRacks)
+	sameRackCount := existingRacks[possibleLocation.Rack()]
+
+	// ensure rack count is within limit
+	if _, found := existingRacks[possibleLocation.Rack()]; !found {
+		// different from existing racks
+		if len(existingRacks) < replicaPlacement.DiffRackCount+1 {
+			// lack on different racks
+			return true
+		} else {
+			// adding this would go over the different racks limit
+			return false
+		}
+	}
+	// now this is same as one of the existing racks
+	if !isAmong(possibleLocation.Rack(), primaryRacks) {
+		// not on the primary rack
+		return false
 	}
 
+	// now this is on the primary rack
+
+	// different from existing data nodes
+	if sameRackCount < replicaPlacement.SameRackCount+1 {
+		// lack on same rack
+		return true
+	} else {
+		// adding this would go over the same data node limit
+		return false
+	}
+
+}
+
+func findTopKeys(m map[string]int) (topKeys []string, max int) {
+	for k, c := range m {
+		if max < c {
+			topKeys = topKeys[:0]
+			topKeys = append(topKeys, k)
+			max = c
+		} else if max == c {
+			topKeys = append(topKeys, k)
+		}
+	}
+	return
+}
+
+func isAmong(key string, keys []string) bool {
+	for _, k := range keys {
+		if k == key {
+			return true
+		}
+	}
 	return false
 }