diff --git a/docker/prometheus/prometheus.yml b/docker/prometheus/prometheus.yml
index 34f669d56..2f0ead441 100644
--- a/docker/prometheus/prometheus.yml
+++ b/docker/prometheus/prometheus.yml
@@ -8,6 +8,7 @@ scrape_configs:
     static_configs:
       - targets:
           - 'prometheus:9090'
+          - 'master:9324'
           - 'volume:9325'
           - 'filer:9326'
           - 's3:9327'
\ No newline at end of file
diff --git a/docker/seaweedfs-compose.yml b/docker/seaweedfs-compose.yml
index 706f10180..cce1c39ef 100644
--- a/docker/seaweedfs-compose.yml
+++ b/docker/seaweedfs-compose.yml
@@ -6,7 +6,8 @@ services:
     ports:
       - 9333:9333
       - 19333:19333
-    command: "master -ip=master -ip.bind=0.0.0.0"
+      - 9324:9324
+    command: "master -ip=master -ip.bind=0.0.0.0 -metricsPort=9324"
   volume:
     image: chrislusf/seaweedfs # use a remote image
     ports:
diff --git a/weed/server/filer_ui/filer.html b/weed/server/filer_ui/filer.html
index 785f82887..f9c35440e 100644
--- a/weed/server/filer_ui/filer.html
+++ b/weed/server/filer_ui/filer.html
@@ -225,6 +225,10 @@
         handleFiles(files);
     }
 
+    function reloadPage() {
+        window.location.reload(true);
+    }
+
     var uploadList = {};
 
     function handleFiles(files) {
@@ -277,7 +281,7 @@
         }
         if (allFinish) {
             console.log('All Finish');
-            window.location.reload();
+            reloadPage();
         }
     }
 
@@ -318,7 +322,7 @@
         xhr.open('POST', url, false);
         xhr.setRequestHeader('Content-Type', '');
         xhr.send();
-        window.location.reload();
+        reloadPage();
     }
 
     function handleRename(originName, basePath) {
@@ -333,7 +337,7 @@
         xhr.open('POST', url, false);
         xhr.setRequestHeader('Content-Type', '');
         xhr.send();
-        window.location.reload();
+        reloadPage();
     }
 
     function handleDelete(path) {
@@ -348,7 +352,7 @@
         var xhr = new XMLHttpRequest();
         xhr.open('DELETE', url, false);
         xhr.send();
-        window.location.reload();
+        reloadPage();
     }
 </script>
 </html>
diff --git a/weed/server/volume_grpc_client_to_master.go b/weed/server/volume_grpc_client_to_master.go
index d4f3b2853..078b78eb2 100644
--- a/weed/server/volume_grpc_client_to_master.go
+++ b/weed/server/volume_grpc_client_to_master.go
@@ -119,15 +119,15 @@ func (vs *VolumeServer) doHeartbeat(masterAddress pb.ServerAddress, grpcDialOpti
 				return
 			}
 			if len(in.DuplicatedUuids) > 0 {
-				var duplictedDir []string
+				var duplicateDir []string
 				for _, loc := range vs.store.Locations {
 					for _, uuid := range in.DuplicatedUuids {
 						if uuid == loc.DirectoryUuid {
-							duplictedDir = append(duplictedDir, loc.Directory)
+							duplicateDir = append(duplicateDir, loc.Directory)
 						}
 					}
 				}
-				glog.Errorf("Shut down Volume Server due to duplicated volume directories: %v", duplictedDir)
+				glog.Errorf("Shut down Volume Server due to duplicate volume directories: %v", duplicateDir)
 				os.Exit(1)
 			}
 			if in.GetVolumeSizeLimit() != 0 && vs.store.GetVolumeSizeLimit() != in.GetVolumeSizeLimit() {
diff --git a/weed/stats/metrics.go b/weed/stats/metrics.go
index 8381999c2..943aafff9 100644
--- a/weed/stats/metrics.go
+++ b/weed/stats/metrics.go
@@ -44,6 +44,14 @@ var (
 			Help:      "Counter of master received heartbeat.",
 		}, []string{"type"})
 
+	MasterReplicaPlacementMismatch = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: "SeaweedFS",
+			Subsystem: "master",
+			Name:      "replica_placement_mismatch",
+			Help:      "replica placement mismatch",
+		}, []string{"collection", "id"})
+
 	MasterLeaderChangeCounter = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Namespace: "SeaweedFS",
@@ -165,6 +173,7 @@ func init() {
 	Gather.MustRegister(MasterRaftIsleader)
 	Gather.MustRegister(MasterReceivedHeartbeatCounter)
 	Gather.MustRegister(MasterLeaderChangeCounter)
+	Gather.MustRegister(MasterReplicaPlacementMismatch)
 
 	Gather.MustRegister(FilerRequestCounter)
 	Gather.MustRegister(FilerRequestHistogram)
diff --git a/weed/topology/node.go b/weed/topology/node.go
index 4772cb411..c5956177a 100644
--- a/weed/topology/node.go
+++ b/weed/topology/node.go
@@ -3,6 +3,7 @@ package topology
 import (
 	"errors"
 	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/stats"
 	"github.com/chrislusf/seaweedfs/weed/storage/erasure_coding"
 	"github.com/chrislusf/seaweedfs/weed/storage/needle"
 	"github.com/chrislusf/seaweedfs/weed/storage/types"
@@ -246,6 +247,14 @@ func (n *NodeImpl) CollectDeadNodeAndFullVolumes(freshThreshHold int64, volumeSi
 				} else if float64(v.Size) > float64(volumeSizeLimit)*growThreshold {
 					n.GetTopology().chanCrowdedVolumes <- v
 				}
+				copyCount := v.ReplicaPlacement.GetCopyCount()
+				if copyCount > 1 {
+					if copyCount > len(n.GetTopology().Lookup(v.Collection, v.Id)) {
+						stats.MasterReplicaPlacementMismatch.WithLabelValues(v.Collection, v.Id.String()).Set(1)
+					} else {
+						stats.MasterReplicaPlacementMismatch.WithLabelValues(v.Collection, v.Id.String()).Set(0)
+					}
+				}
 			}
 		}
 	} else {