diff --git a/internal/client/client.go b/internal/client/client.go
index 780415e6..9e76f01e 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -121,6 +121,7 @@ func (r *Runtime) Info() (cs Source, host string) {
 
 // SetInfo sets a host as a client information from the cs.
 func (r *Runtime) SetInfo(cs Source, hosts []string) {
+	// TODO(s.chzhen):  Use contract where hosts must contain non-empty host.
 	if len(hosts) == 1 && hosts[0] == "" {
 		hosts = []string{}
 	}
diff --git a/internal/client/storage.go b/internal/client/storage.go
index 66601812..23bb6ca8 100644
--- a/internal/client/storage.go
+++ b/internal/client/storage.go
@@ -237,21 +237,21 @@ func (s *Storage) ClientRuntime(ip netip.Addr) (rc *Runtime) {
 
 // UpdateRuntime updates the stored runtime client with information from rc.  If
 // no such client exists, saves the copy of rc in storage.  rc must not be nil.
-func (s *Storage) UpdateRuntime(rc *Runtime) {
+func (s *Storage) UpdateRuntime(rc *Runtime) (added bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	s.updateRuntimeLocked(rc)
+	return s.updateRuntimeLocked(rc)
 }
 
 // updateRuntimeLocked updates the stored runtime client with information from
 // rc.  rc must not be nil.  Storage.mu is expected to be locked.
-func (s *Storage) updateRuntimeLocked(rc *Runtime) {
+func (s *Storage) updateRuntimeLocked(rc *Runtime) (added bool) {
 	stored := s.runtimeIndex.Client(rc.ip)
 	if stored == nil {
 		s.runtimeIndex.Add(rc.Clone())
 
-		return
+		return true
 	}
 
 	if rc.whois != nil {
@@ -273,11 +273,13 @@ func (s *Storage) updateRuntimeLocked(rc *Runtime) {
 	if rc.hostsFile != nil {
 		stored.hostsFile = slices.Clone(rc.hostsFile)
 	}
+
+	return false
 }
 
 // BatchUpdateBySource updates the stored runtime clients information from the
-// specified source.
-func (s *Storage) BatchUpdateBySource(src Source, rcs []*Runtime) {
+// specified source and returns the number of added and removed clients.
+func (s *Storage) BatchUpdateBySource(src Source, rcs []*Runtime) (added, removed int) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
@@ -286,14 +288,19 @@ func (s *Storage) BatchUpdateBySource(src Source, rcs []*Runtime) {
 	}
 
 	for _, rc := range rcs {
-		s.updateRuntimeLocked(rc)
+		if s.updateRuntimeLocked(rc) {
+			added++
+		}
 	}
 
 	for ip, rc := range s.runtimeIndex.index {
 		if rc.isEmpty() {
 			delete(s.runtimeIndex.index, ip)
+			removed++
 		}
 	}
+
+	return added, removed
 }
 
 // SizeRuntime returns the number of the runtime clients.
diff --git a/internal/client/storage_test.go b/internal/client/storage_test.go
index 4a534580..5ac02747 100644
--- a/internal/client/storage_test.go
+++ b/internal/client/storage_test.go
@@ -659,7 +659,7 @@ func TestStorage_UpdateRuntime(t *testing.T) {
 		added := client.NewRuntime(ip)
 		added.SetInfo(client.SourceARP, []string{addedARP})
 
-		s.UpdateRuntime(added)
+		require.True(t, s.UpdateRuntime(added))
 		require.Equal(t, 1, s.SizeRuntime())
 
 		got := s.ClientRuntime(ip)
@@ -672,7 +672,7 @@ func TestStorage_UpdateRuntime(t *testing.T) {
 		added := client.NewRuntime(ip2)
 		added.SetInfo(client.SourceARP, []string{addedSecondARP})
 
-		s.UpdateRuntime(added)
+		require.True(t, s.UpdateRuntime(added))
 		require.Equal(t, 2, s.SizeRuntime())
 
 		got := s.ClientRuntime(ip2)
@@ -682,7 +682,7 @@ func TestStorage_UpdateRuntime(t *testing.T) {
 	})
 
 	t.Run("update_first_client", func(t *testing.T) {
-		s.UpdateRuntime(updated)
+		require.False(t, s.UpdateRuntime(updated))
 		got := s.ClientRuntime(ip)
 		require.Equal(t, 2, s.SizeRuntime())
 
@@ -744,7 +744,9 @@ func TestStorage_BatchUpdateBySource(t *testing.T) {
 	})
 
 	t.Run("populate_storage_with_first_clients", func(t *testing.T) {
-		s.BatchUpdateBySource(defSrc, firstClients)
+		added, removed := s.BatchUpdateBySource(defSrc, firstClients)
+		require.Equal(t, len(firstClients), added)
+		require.Equal(t, 0, removed)
 		require.Equal(t, len(firstClients), s.SizeRuntime())
 
 		rc := s.ClientRuntime(cliFirstIP1)
@@ -754,7 +756,9 @@ func TestStorage_BatchUpdateBySource(t *testing.T) {
 	})
 
 	t.Run("update_storage", func(t *testing.T) {
-		s.BatchUpdateBySource(defSrc, updatedClients)
+		added, removed := s.BatchUpdateBySource(defSrc, updatedClients)
+		require.Equal(t, len(updatedClients), added)
+		require.Equal(t, len(firstClients), removed)
 		require.Equal(t, len(updatedClients), s.SizeRuntime())
 
 		rc := s.ClientRuntime(cliUpdatedIP3)
@@ -767,7 +771,9 @@ func TestStorage_BatchUpdateBySource(t *testing.T) {
 	})
 
 	t.Run("remove_all", func(t *testing.T) {
-		s.BatchUpdateBySource(defSrc, []*client.Runtime{})
+		added, removed := s.BatchUpdateBySource(defSrc, []*client.Runtime{})
+		require.Equal(t, 0, added)
+		require.Equal(t, len(updatedClients), removed)
 		require.Equal(t, 0, s.SizeRuntime())
 	})
 }
diff --git a/internal/home/clients.go b/internal/home/clients.go
index e64f5d15..819564bc 100644
--- a/internal/home/clients.go
+++ b/internal/home/clients.go
@@ -642,7 +642,6 @@ func (clients *clientsContainer) addFromHostsFile(hosts *hostsfile.DefaultStorag
 	clients.lock.Lock()
 	defer clients.lock.Unlock()
 
-	added := 0
 	var rcs []*client.Runtime
 	hosts.RangeNames(func(addr netip.Addr, names []string) (cont bool) {
 		// Only the first name of the first record is considered a canonical
@@ -652,15 +651,13 @@ func (clients *clientsContainer) addFromHostsFile(hosts *hostsfile.DefaultStorag
 		rc := client.NewRuntime(addr)
 		rc.SetInfo(client.SourceHostsFile, []string{names[0]})
 
-		added++
 		rcs = append(rcs, rc)
 
 		return true
 	})
 
-	clients.storage.BatchUpdateBySource(client.SourceHostsFile, rcs)
-
-	log.Debug("clients: added %d client aliases from system hosts file", added)
+	added, removed := clients.storage.BatchUpdateBySource(client.SourceHostsFile, rcs)
+	log.Debug("clients: added %d, removed %d client aliases from system hosts file", added, removed)
 }
 
 // addFromSystemARP adds the IP-hostname pairings from the output of the arp -a
@@ -684,19 +681,16 @@ func (clients *clientsContainer) addFromSystemARP() {
 	clients.lock.Lock()
 	defer clients.lock.Unlock()
 
-	added := 0
 	var rcs []*client.Runtime
 	for _, n := range ns {
 		rc := client.NewRuntime(n.IP)
 		rc.SetInfo(client.SourceARP, []string{n.Name})
 
-		added++
 		rcs = append(rcs, rc)
 	}
 
-	clients.storage.BatchUpdateBySource(client.SourceARP, rcs)
-
-	log.Debug("clients: added %d client aliases from arp neighborhood", added)
+	added, removed := clients.storage.BatchUpdateBySource(client.SourceARP, rcs)
+	log.Debug("clients: added %d, removed %d client aliases from arp neighborhood", added, removed)
 }
 
 // close gracefully closes all the client-specific upstream configurations of