Grid Services Monitoring Working Group

Displaying Aggregated Service Metrics in Ganglia

NOTE: The publisher script distributed with the Nagios prototype has changed and currently this ganglia integration is not possible.

The Nagios-based monitoring prototype is distributed with a "publisher" .cgi script to calculate aggregate service metrics and publish these through the web interface as XML.

Whilst other Nagios-Ganglia integration methods are possible this documented describes a simple integration of this XML publisher interface allowing aggregated metrics to be displayed in graphical form in the Ganglia monitoring system Cluster view as shown in the screen clip below.

• ganglia_shot.PNG:
  

1. Download the script wlcg2ganglia.pl from the repository here and install in /opt/lcg/sbin/.
2. Check you have the prerequisite perl module XML::XPath (rpm perl-XML-XPath) installed.
3. Install a cron (e.g. on the Ganglia server) to fetch the aggregate metrics published on the Nagios server and push them into Ganglia. Note ganglia 3.0.4 or above is required because of the use of gmetric host 'spoofing' feature. e.g. create /etc/cron.d/wlcg2ganglia with contents as follows

         PATH=/sbin:/bin:/usr/sbin:/usr/bin
         * * * * * nobody /opt/lcg/sbin/wlcg2ganglia.pl -s CERN_PPS \
                   -u https://pps-monitoring.cern.ch/cgi-bin/publisher.cgi  >> /dev/null 2>&1 

4. Patch 2 ganglia .php files in /var/www/html/ganglia using the patch data below.

When completed 3 additional summary graphs for local and remote (SAM & NPM) metrics should be displayed in the Ganglia Cluster view.

*** graph.php   2007-07-30 17:10:16.000000000 +0200
--- graph.php_iann      2007-07-30 17:06:00.000000000 +0200
***************
*** 210,217 ****
--- 210,241 ----
                 ."DEF:'bytes_out'='${rrd_dir}/pkts_out.rrd':'sum':AVERAGE "
                 ."LINE2:'bytes_in'#$mem_cached_color:'In' "
                 ."LINE2:'bytes_out'#$mem_used_color:'Out' ";
           }
+       #
+       # Handle aggregate WLCG metrics
+       # (eg. sam, local and npm, but this code does not care
+       # and looks for org.wlcg.aggregate-status.xxxx_report)
+       #
+       else if (strncmp($graph,"org.wlcg.aggregate-status.",26) == 0 )
+          {
+              # Construct the name of the rrd file from the graph name
+              $metric = substr($graph,0,strlen($graph)-7);
+              # Chop the graph name up to make a useful title string
+              $style =  substr($metric,4,strlen($metric)-4);
+              $style =  substr($metric,4,strlen($metric)-4);
+
+              $upper_limit = "--upper-limit 10";
+              $lower_limit = "--lower-limit 0";
+
+              $vertical_label = "--vertical-label Services ";
+
+              $series ="DEF:'ok'='${rrd_dir}/${metric}.rrd':'sum':AVERAGE "
+                      ."DEF:'total'='${rrd_dir}/${metric}.rrd':'num':AVERAGE "
+                      ."CDEF:'crit'=total,ok,- "
+                      ."AREA:'ok'#00FF00:'OK' "
+                      ."STACK:'crit'#FF0000:'CRITICAL' ";
+          }
        else
           {
              /* Got a strange value for $graph */
              exit();

*** cluster_view.php    2007-07-30 17:18:54.000000000 +0200
--- cluster_view.php_iann       2007-07-30 17:18:14.000000000 +0200
***************
*** 36,44 ****
  #
  $graph_args = "c=$cluster_url&$get_metric_string&st=$cluster[LOCALTIME]";
  $tpl->assign("graph_args", $graph_args);
  if (!isset($optional_graphs))
!       $optional_graphs = array();
  foreach ($optional_graphs as $g) {
        $tpl->newBlock('optional_graphs');
        $tpl->assign('name',$g);
        $tpl->assign('graph_args',$graph_args);
--- 36,46 ----
  #
  $graph_args = "c=$cluster_url&$get_metric_string&st=$cluster[LOCALTIME]";
  $tpl->assign("graph_args", $graph_args);
  if (!isset($optional_graphs))
!       $optional_graphs = array("org.wlcg.aggregate-status.sam",
!                                  "org.wlcg.aggregate-status.local",
!                                  "org.wlcg.aggregate-status.npm");
  foreach ($optional_graphs as $g) {
        $tpl->newBlock('optional_graphs');
        $tpl->assign('name',$g);
        $tpl->assign('graph_args',$graph_args);

-- IanNeilson - 31 Jul 2007

• ganglia_shot.PNG: