diff --git a/xCAT-rmc/plugin/rmcmon.pm b/xCAT-rmc/plugin/rmcmon.pm
index e8cfeb459..b128a8787 100644
--- a/xCAT-rmc/plugin/rmcmon.pm
+++ b/xCAT-rmc/plugin/rmcmon.pm
@@ -13,8 +13,18 @@ use xCAT::Utils;
 use xCAT::GlobalDef;
 
 #print "xCAT_monitoring::rmcmon loaded\n";
-
 1;
+
+#now the RMC domain can automatically setup when xCAT starts. predefined conditions and sensor are defined on ms.
+#TODO: conveting all print statement to logging
+#TODO: predefined responses
+#TODO: node status monitoring for xCAT.
+#TODO: script to define sensors on the nodes.
+#TODO: how to push the sensor scripts to nodes?
+#TODO: what to do when stop is called? stop all the associations or just the ones that were predefined? or leve them there?
+#TODO: do we need to stop all the RMC daemons when stop is called?
+#I will come back to work on these once I have SNMP stuff done. 
+
 #-------------------------------------------------------------------------------
 =head1  xCAT_monitoring:rmcmon  
 =head2    Package Description
@@ -66,29 +76,115 @@ sub start {
       return (1, "rmc deamon cannot be started\n");
     }
   }
+
+  #enable remote client connection
+  `/usr/bin/rmcctrl -p`;
   
   #get a list of managed nodes
-  $result=`/usr/bin/lsrsrc-api -s IBM.MngNode::::Name`;
+  $result=`/usr/bin/lsrsrc-api -s IBM.MngNode::::Name 2>&1`;  
+  if ($?) {
+    if ($result !~ /2612-023/) {#2612-023 no resources found error
+      print "$result\n";
+      return (1,$result);
+    }
+    $result='';
+  }
   chomp($result);
   my @rmc_nodes=split(/\n/, $result);
+  #print "all defined nodes=@rmc_nodes\n";
 
-  foreach (keys(%$noderef)) {
-    my $server=$_;
+  my $localhostname=hostname();
+  my $mon_nodes=$noderef->{$localhostname};
 
-    my $mon_nodes=$noderef->{$_};
+  #check what has changed 
+  my %summary;
+  foreach (@rmc_nodes) { $summary{$_}=-1;}
+  if ($mon_nodes) {
     foreach(@$mon_nodes) {
-      my $node_pair=$_;
-      my $node=$node_pair->[0];
-      my $nodetype=$node_pair->[1];
-       
+      my $node=$_->[0];
+      my $nodetype=$_->[1];
+      if ((!$nodetype) || ($nodetype =~ /$::NODETYPE_OSI/)) { 
+        $summary{$node}++;
+      }  
+    }     
+  }
+
+  my @nodes_to_add=();
+  my @nodes_to_remove=();
+  foreach(keys(%summary)) {
+    #print "node=$_ summary=$summary{$_}\n";
+    if ($summary{$_}==1) {push(@nodes_to_add, $_);}  
+    elsif ($summary{$_}==-1) {push(@nodes_to_remove, $_);}      
+  }
+ 
+  #add new nodes to the RMC cluster
+  if (@nodes_to_add>0) { 
+    my %nodes_status=xCAT_monitoring::rmcmon::pingNodeStatus(@nodes_to_add); 
+    my $active_nodes=$nodes_status{$::STATUS_ACTIVE};
+    my $inactive_nodes=$nodes_status{$::STATUS_INACTIVE};
+    if (@$inactive_nodes>0) { 
+      print "The following nodes cannot be added to the RMC cluster because they are inactive:\n  @$inactive_nodes\n"
     }
+    if (@$active_nodes>0) {
+     print "active nodes to add:\n  @$active_nodes\n";
+     addNodes_noChecking(@$active_nodes);
+    }
+  }  
+
+  #remove unwanted nodes to the RMC cluster
+  if (@nodes_to_remove>0) {
+    print "nodes to remove @nodes_to_remove\n"; 
+    removeNodes_noChecking(@nodes_to_remove);
+  }  
+
+  #start condition-response assosciations 
+  my $result=`$::XCATROOT/sbin/rmcmon/mkrmcresources $::XCATROOT/lib/perl/xCAT_monitoring/rmc/resources/ms 2>&1`;
+  if ($?) {
+    print "Error when creating predefined resources on $localhostname:\n$result\n";
+  }
+
+  return (0, "started");
+}
+
+
+#--------------------------------------------------------------------------------
+=head3    pingNodeStatus
+      This function takes an array of nodes and returns their status using fping.
+    Arguments:
+       nodes-- an array of nodes.
+    Returns:
+       a hash that has the node status. The format is: 
+          {active=>[node1, node3,...], unreachable=>[node4, node2...]}
+=cut
+#--------------------------------------------------------------------------------
+sub pingNodeStatus {
+  my ($class, @mon_nodes)=@_;
+  %status=();
+  my @active_nodes=();
+  my @inactive_nodes=();
+  if ((@mon_nodes)&& (@mon_nodes > 0)) {
+    #get all the active nodes
+    my $nodes= join(' ', @mon_nodes);
+    my $temp=`fping -a $nodes 2> /dev/null`;
+    chomp($temp);
+    @active_nodes=split(/\n/, $temp);
+
+    #get all the inactive nodes by substracting the active nodes from all.
+    my %temp2;
+    if ((@active_nodes) && ( @active_nodes > 0)) {
+      foreach(@active_nodes) { $temp2{$_}=1};
+        foreach(@mon_nodes) {
+          if (!$temp2{$_}) { push(@inactive_nodes, $_);}
+        }
+    }
+    else {@inactive_nodes=@mon_nodes;}     
   }
 
   
-
-  #TODO: start condition-response assosciations 
-
-  return (0, "started");
+  $status{$::STATUS_ACTIVE}=\@active_nodes;
+  $status{$::STATUS_INACTIVE}=\@inactive_nodes;
+ 
+  return %status;
 }
 
 
@@ -176,7 +272,7 @@ sub stopNodeStatusMon {
 
 #--------------------------------------------------------------------------------
 =head3    addNodes
-      This function gdds the nodes into the RMC cluster.
+      This function adds the nodes into the RMC cluster.
     Arguments:
       nodes --nodes to be added. It is a  hash reference keyed by the monitoring server 
         nodes and each value is a ref to an array of [nodes, nodetype, status] arrays  monitored 
@@ -188,130 +284,143 @@ sub stopNodeStatusMon {
 =cut
 #--------------------------------------------------------------------------------
 sub addNodes {
-  $noderef=shift;
+  my $noderef=shift;
   if ($noderef =~ /xCAT_monitoring::rmcmon/) {
     $noderef=shift;
   }
-  my $VERBOSE=shift;
-
-  #if ($VERBOSE) { print "rmcmon::addNodes called $noderef=$noderef\n"};
+  
+  #print "rmcmon::addNodes get called\n";
+  
 
   my $ms_host_name=hostname();
-  chomp($ms_host_name);
+  my $mon_nodes=$noderef->{$ms_host_name};
 
-  foreach (keys(%$noderef)) {
-    my $server=$_;
-    #if ($VERBOSE) { print "  monitoring server: $server\n";}
+  my @nodes_to_add=();
+  foreach(@$mon_nodes) {
+    my $node_pair=$_;
+    my $node=$node_pair->[0];
+    my $nodetype=$node_pair->[1];
+    if ((!$nodetype) || ($nodetype =~ /$::NODETYPE_OSI/)) {
+      #RMC deals only with osi type. empty type is treated as osi type
+      #check if the node has already defined
+      $result=`lsrsrc-api -s IBM.MngNode::"Name=\\\"\"$node\\\"\"" 2>&1`;
+      if (($?) && ($result !~ /2612-023/)) { #2612-023 no resources found error
+	print "$result\n";
+        next;
+      } 
 
-    if ($server ne $ms_host_name) {
-      next; #only handle the nodes which has this node as the monitor server
-    } 
-
-    #check if rsct is installed and running
-    if (! -e "/usr/bin/lsrsrc") {
-      print "RSCT is not installed.\n";
-      return 1;
-    }
-    my $result=`/usr/bin/lssrc -s ctrmc`;
-    if ($result !~ /active/) {
-      #restart rmc daemon
-      $result=`startsrc -s ctrmc`;
-      if ($?) {
-        print "rmc deamon cannot be started\n";
-        return 1;
-      }
-    }
-
-    #enable remote client connection
-    `/usr/bin/rmcctrl -p`;
-
-    #ms node id, hostname, ip defs
-    my $ms_node_id;
-    my $ms_name,$ms_aliases,$ms_addrtype,$ms_length,@ms_addrs;
-    my $ms_ipaddresses;
-
-    #if ($VERBOSE) {
-    #  print "    ms_host_name=$ms_host_name, ms_nam=$ms_name, ms_aliases=$ms_aliases, ms_ip_addr=$ms_ipaddresses, ms_node_id=$ms_node_id\n";
-    #}
-
-    my $mon_nodes=$noderef->{$_};
-    my $first_time=1;
-    foreach(@$mon_nodes) {
-      my $node_pair=$_;
-      my $node=$node_pair->[0];
-      my $nodetype=$node_pair->[1]; 
-      if ((!$nodetype) || ($nodetype =~ /$::NODETYPE_OSI/)) {
-        #RMC deals only with osi type. empty type is treated as osi type
-        #check if the node has already defined
-        $result=`lsrsrc-api -s IBM.MngNode::"Name=\\\"\"$node\\\"\"" 2>&1`;
-        if ($? == 0) { #resource has already defined
-	  next;
-        }
-
-        #TODO: check all nodes at the same time or use the 'status' value in the node
+      #TODO: check all nodes at the same time or use the 'status' value in the node
+      if ($ms_host_name ne $node) {
         `fping -a $node 2> /dev/null`;
         if ($?) {
-	  print "Cannot add the node $node into the RMC domian. The node is inactive.\n";
-	  next;
-        }
-
-        if ($first_time) {
-	  $first_time=0;
-
-          #enable remote client connection
-          `/usr/bin/rmcctrl -p`;
-
-          #get ms node id, hostname, ip etc
-          $ms_node_id=`head -n 1 /var/ct/cfg/ct_node_id`;
-          chomp($ms_node_id);
-          ($ms_name,$ms_aliases,$ms_addrtype,$ms_length,@ms_addrs) = gethostbyname($ms_host_name);
-          chomp($ms_name);
-
-          $ms_ipaddresses="{";
-          foreach (@ms_addrs) {
-            $ms_ipaddresses .= '"' .inet_ntoa($_) . '",';
-          }
-          chop($ms_ipaddresses);
-          $ms_ipaddresses .= "}";
-        }
-
-        #get info for the node
-        $mn_node_id=`psh $node "head -n 1 /var/ct/cfg/ct_node_id" 2>&1`;
-        $mn_node_id =~ s/.*([0-9 a-g]{16}).*/$1/s;
-
-        my ($mn_name,$mn_aliases,$mn_addrtype,$mn_length,@mn_addrs) = gethostbyname($node);
-        chomp($mn_name);
-        my $mn_ipaddresses="{";
-        foreach (@mn_addrs) {
-          $mn_ipaddresses .= '"'.inet_ntoa($_) . '",';
-        }
-        chop($mn_ipaddresses);
-        $mn_ipaddresses .= "}";
-        #if ($VERBOSE) {
-        #  print "    mn_name=$mn_name, mn_aliases=$mn_aliases,   mn_ipaddr=$mn_ipaddresses,  mn_node_id=$mn_node_id\n";          
-        #}
-
-        # define resource in IBM.MngNode class on server
-        $result=`mkrsrc-api IBM.MngNode::Name::"$node"::KeyToken::"$node"::IPAddresses::"$mn_ipaddresses"::NodeID::0x$mn_node_id 2>&1`;
-        if ($?) {
-          print "define resource in IBM.MngNode class result=$result\n"; 
-        }
-
-        #copy the configuration script and run it locally
-        $result=`scp $::XCATROOT/sbin/rmcmon/configrmcnode $node:/tmp 2>&1`;
-        if ($?) {
-          print "rmcmon:addNodes: cannot copy the file configrmcnode to node $node\n";
+          print "Cannot add the node $node into the RMC domian. The node is inactive.\n";
           next;
         }
+      }
 
-        $result=`psh $node /tmp/configrmcnode -a $node $ms_host_name $ms_ipaddresses 0x$ms_node_id 2>&1`;
-        if ($?) {
-          print "$result\n";
-        }
-      } 
-    }
+      push(@nodes_to_add, $node); 
+    } 
   }
 
+  if (@nodes_to_add>0) {
+    return addNodes_noChecking(@nodes_to_add);
+  }
+   
+  return 0;
+}
+
+#--------------------------------------------------------------------------------
+=head3    addNodes_noChecking
+      This function gdds the nodes into the RMC cluster, it does not check the OSI type and
+      if the node has already defined. 
+    Arguments:
+      nodes --an array of nodes to be added. 
+    Returns:
+       none
+=cut
+#--------------------------------------------------------------------------------
+sub addNodes_noChecking {
+ 
+  @mon_nodes = @_;
+  #print "rmcmon::addNodes_noChecking get called with @mon_nodes\n";
+  my $ms_host_name=hostname();
+
+  my $ms_node_id;
+  my $mn_node_id;
+  my $ms_name,$ms_aliases,$ms_addrtype,$ms_length,@ms_addrs;
+  my $ms_ipaddresses;
+
+  my $first_time=1;
+  foreach(@mon_nodes) {
+      
+    my $node=$_;
+
+    if ($first_time) {
+      $first_time=0;
+      #get ms node id, hostname, ip etc
+      $ms_node_id=`head -n 1 /var/ct/cfg/ct_node_id`;
+      chomp($ms_node_id);
+      ($ms_name,$ms_aliases,$ms_addrtype,$ms_length,@ms_addrs) = gethostbyname($ms_host_name);
+      chomp($ms_name);
+
+      $ms_ipaddresses="{";
+      foreach (@ms_addrs) {
+        $ms_ipaddresses .= '"' .inet_ntoa($_) . '",';
+      }
+      chop($ms_ipaddresses);
+      $ms_ipaddresses .= "}";
+    }
+
+    #get info for the node
+    if($ms_host_name eq $node) {
+      $mn_node_id=$ms_node_id;
+    } else { 
+      $mn_node_id=`$::XCATROOT/bin/psh --nonodecheck $node "head -n 1 /var/ct/cfg/ct_node_id" 2>&1`;
+      if ($?) {
+	print "Cannot get NodeID for $node. $mn_node_id\n";
+        next;
+      }
+      if ($mn_node_id =~ s/.*([0-9 a-g]{16}).*/$1/s) {;}
+      else { print "No node id found for $node:\n$mn_node_id\n"; next;}
+    }
+
+    my ($mn_name,$mn_aliases,$mn_addrtype,$mn_length,@mn_addrs) = gethostbyname($node);
+    chomp($mn_name);
+    my $mn_ipaddresses="{";
+    foreach (@mn_addrs) {
+      $mn_ipaddresses .= '"'.inet_ntoa($_) . '",';
+    }
+    chop($mn_ipaddresses);
+    $mn_ipaddresses .= "}";
+    #  print "    mn_name=$mn_name, mn_aliases=$mn_aliases,   mn_ipaddr=$mn_ipaddresses,  mn_node_id=$mn_node_id\n";          
+
+    # define resource in IBM.MngNode class on server
+    $result=`mkrsrc-api IBM.MngNode::Name::"$node"::KeyToken::"$node"::IPAddresses::"$mn_ipaddresses"::NodeID::0x$mn_node_id 2>&1`;
+    if ($?) {
+      print "define resource in IBM.MngNode class result=$result\n";
+      next; 
+    }
+
+    #copy the configuration script and run it locally
+    if($ms_host_name eq $node) {
+      $result=`/usr/bin/mkrsrc-api IBM.MCP::MNName::"$node"::KeyToken::"$ms_host_name"::IPAddresses::"$ms_ipaddresses"::NodeID::0x$ms_node_id`;      
+      if ($?) {
+        print "$result\n";
+        next;
+      }
+    } else {
+      $result=`scp $::XCATROOT/sbin/rmcmon/configrmcnode $node:/tmp 2>&1`;
+      if ($?) {
+        print "rmcmon:addNodes: cannot copy the file configrmcnode to node $node\n";
+        next;
+      }
+
+      $result=`$::XCATROOT/bin/psh --nonodecheck $node /tmp/configrmcnode -a $node $ms_host_name $ms_ipaddresses 0x$ms_node_id 2>&1`;
+      if ($?) {
+        print "$result\n";
+      }
+    }
+  } 
 
   return 0;
 }
@@ -330,59 +439,91 @@ sub addNodes {
 =cut
 #--------------------------------------------------------------------------------
 sub removeNodes {
-  $noderef=shift;
+  my $noderef=shift;
   if ($noderef =~ /xCAT_monitoring::rmcmon/) {
     $noderef=shift;
   }
-  my $VERBOSE=shift;
 
-  #if ($VERBOSE) { print "rmcmon::removeNodes called\n"};
+  #print "rmcmon::removeNodes called\n";
+  my $ms_host_name=hostname();
+  my $mon_nodes=$noderef->{$ms_host_name};
 
-  my $local_host_name=hostname();
-  chomp($local_host_name);
-  foreach (keys(%$noderef)) {
-    $server=$_;
-    #print "  monitoring server: $server local_host_name=$local_host_name\n";
-    #only handle the nodes which has this node as the monitor server
-    if ($server ne $local_host_name) {next; } 
+  my @nodes_to_remove=();
 
-    my $mon_nodes=$noderef->{$_};
-    foreach(@$mon_nodes) {
-      my $node_pair=$_;
-      my $node=$node_pair->[0];
-      my $nodetype=$node_pair->[1]; 
-      if ((!$nodetype) || ($nodetype =~ /$::NODETYPE_OSI/)) {
-        #RMC deals only with osi type. empty type is treated as osi type
-
-
-        #remove resource in IBM.MngNode class on server
-        my $result=`rmrsrc-api -s IBM.MngNode::"Name=\\\"\"$node\\\"\"" 2>&1`;
-	if ($?) { print "remove resource in IBM.MngNode class result=$result\n"; }
-        if ($result =~ m/2612-023/) { #resource not found
-	  next;
-        }
-
-        # TODO: check all the nodes together or use the 'status' value
-        #if the node is inactive, forget it
-        `fping -a $node 2> /dev/null`;
-        if ($?) {
-	  next;
-        }
-
-        #copy the configuration script and run it locally
-        $result=`scp $::XCATROOT/sbin/rmcmon/configrmcnode $node:/tmp 2>&1 `;
-        if ($?) {
-          print "rmcmon:removeNodes: cannot copy the file configrmcnode to node $node\n";
-          next;
-        }
-
-        $result=`psh --nonodecheck $node /tmp/configrmcnode -d $node 2>&1`;
-        if ($?) {
-          print "$result\n";
-        }
-      }           
+  foreach(@$mon_nodes) {
+    my $node_pair=$_;
+    my $node=$node_pair->[0]; 
+    my $nodetype=$node_pair->[1]; 
+    if ((!$nodetype) || ($nodetype =~ /$::NODETYPE_OSI/)) {
+      #RMC deals only with osi type. empty type is treated as osi type
+      push(@nodes_to_remove, $node);
     }
   }
 
+  if (@nodes_to_remove>0) {
+    return removeNodes_noChecking(@nodes_to_remove);
+  }
+
+  return 0;
+}
+
+
+#--------------------------------------------------------------------------------
+=head3    removeNodes_noChecking
+      This function removes the nodes from the RMC cluster.
+    Arguments:
+      nodes --an array of node names to be removed. 
+    Returns:
+       none
+=cut
+#--------------------------------------------------------------------------------
+sub removeNodes_noChecking {
+  my @mon_nodes = @_;
+  my $ms_host_name=hostname();
+ 
+
+  #print "rmcmon::removeNodes_noChecking get called with @mon_nodes\n";
+
+  foreach(@mon_nodes) {
+    my $node=$_;
+
+    #remove resource in IBM.MngNode class on server
+    my $result=`rmrsrc-api -s IBM.MngNode::"Name=\\\"\"$node\\\"\"" 2>&1`;
+    if ($?) {  
+      if ($result =~ m/2612-023/) { #resource not found
+       next;
+      }
+      print "Remove resource in IBM.MngNode class result=$result\n";
+    }
+
+    # TODO: check all the nodes together or use the 'status' value
+    #if the node is inactive, forget it
+    if ($ms_host_name ne $node) {
+      `fping -a $node 2> /dev/null`;
+      if ($?) {
+       next;
+      }
+    }
+
+    if ($ms_host_name eq $node) {
+      $result= `/usr/bin/rmrsrc-api -s IBM.MCP::"MNName=\\\"\"$node\\\"\"" 2>&1`;
+      if ($?) {
+        print "$result\n";
+      }
+    } else {
+      #copy the configuration script and run it locally
+      $result=`scp $::XCATROOT/sbin/rmcmon/configrmcnode $node:/tmp 2>&1 `;
+      if ($?) {
+        print "rmcmon:removeNodes: cannot copy the file configrmcnode to node $node\n";
+        next;
+      }
+
+      $result=`$::XCATROOT/bin/psh --nonodecheck $node /tmp/configrmcnode -d $node 2>&1`;
+      if ($?) {
+        print "$result\n";
+      }
+    }
+  }           
+
   return 0;
 }
diff --git a/xCAT-rmc/scripts/perl/configrmcnode b/xCAT-rmc/scripts/perl/configrmcnode
index c29b17e86..0e586bbf6 100755
--- a/xCAT-rmc/scripts/perl/configrmcnode
+++ b/xCAT-rmc/scripts/perl/configrmcnode
@@ -37,9 +37,9 @@ if ($::ADD) {
   my $result=`/usr/bin/lssrc -s ctrmc`;
   if ($result !~ /active/) {
     #restart rmc daemon
-    $result=`startsrc -s ctrmc`;
+    $result=`startsrc -s ctrmc 2>&1`;
     if ($?) {
-      print "rmc deamon cannot be started\n";
+      print "rmc deamon cannot be started:$result\n";
       exit 1;
     }
   }
@@ -48,8 +48,10 @@ if ($::ADD) {
   `/usr/bin/rmcctrl -p; /usr/bin/refrsrc IBM.MCP`;
 
   #define resource in IBM.MCP class on node       
-  $result=`/usr/bin/mkrsrc-api IBM.MCP::MNName::"$ARGV[0]"::KeyToken::"$ARGV[1]"::IPAddresses::"$ARGV[2]"::NodeID::$ARGV[3]`;
-  print "define resource in IBM.MCP class result=$result\n"; 
+  $result=`/usr/bin/mkrsrc-api IBM.MCP::MNName::"$ARGV[0]"::KeyToken::"$ARGV[1]"::IPAddresses::"$ARGV[2]"::NodeID::$ARGV[3] 2>&1`;
+  if ($?) { print "define resource in IBM.MCP class result=$result\n"; } 
+
+  #TODO: create predefined sensors. How does the scipts get on the node? mount? come with image?
 
   exit 0
 }
@@ -61,8 +63,10 @@ if ($::DELETE) {
   } 
 
   #remove resource in IBM.MCP class on the node
-  my $result= `/usr/bin/rmrsrc-api -s IBM.MCP::"MNName=\\\"\"$ARGV[0]\\\"\""`;
-  print "remove resource in IBM.MCP class result=$result\n"; 
+  my $result= `/usr/bin/rmrsrc-api -s IBM.MCP::"MNName=\\\"\"$ARGV[0]\\\"\"" 2>&1`;
+  if ($?) { print "remove resource in IBM.MCP class result=$result\n"; }
+
+  #TODO: remove predefined sensors,
   
   exit 0;
 }
diff --git a/xCAT-server-2.0/lib/xcat/monitoring/monitorctrl.pm b/xCAT-server-2.0/lib/xcat/monitoring/monitorctrl.pm
index b5d688008..0f4459898 100644
--- a/xCAT-server-2.0/lib/xcat/monitoring/monitorctrl.pm
+++ b/xCAT-server-2.0/lib/xcat/monitoring/monitorctrl.pm
@@ -23,7 +23,7 @@ use xCAT_monitoring::montbhandler;
 
 #stores the module name and the method that is used for the node status monitoring
 #for xCAT.
-$NODESTAT_MON_NAME;
+$NODESTAT_MON_NAME; 
 $masterpid;
 
 1;
@@ -344,6 +344,7 @@ sub startMonitoring {
     if ($aRef) {
       my $module_name=$aRef->[1];
 
+      undef $SIG{CHLD};
       #initialize and start monitoring
       my @ret1 = ${$module_name."::"}{start}->($monservers);
       $ret{$_}=\@ret1;
@@ -382,6 +383,7 @@ sub startNodeStatusMonitoring {
     my $aRef=$PRODUCT_LIST{$pname};
     if ($aRef) {
       my $module_name=$aRef->[1];
+      undef $SIG{CHLD};
       my $method = ${$module_name."::"}{supportNodeStatusMon}->();
       # return value 0 means not support. 1 means yes. 
       if ($method > 0) {