try/except around the ES node stats

In case the stat is missing, or a node doesn't have a stat (like a non data node).

cron/healthToMongo.py

@@ -79,14 +79,18 @@ def getEsNodesStats():
     jsonobj = r.json()
     results = []
     for nodeid in jsonobj['nodes']:
-        results.append({
-            'hostname': jsonobj['nodes'][nodeid]['host'],
-            'disk_free': jsonobj['nodes'][nodeid]['fs']['total']['free_in_bytes'] / (1024 * 1024 * 1024),
-            'disk_total': jsonobj['nodes'][nodeid]['fs']['total']['total_in_bytes'] / (1024 * 1024 * 1024),
-            'mem_heap_per': jsonobj['nodes'][nodeid]['jvm']['mem']['heap_used_percent'],
-            'cpu_usage': jsonobj['nodes'][nodeid]['os']['cpu_percent'],
-            'load': jsonobj['nodes'][nodeid]['os']['load_average']
-        })
+        try:
+            results.append({
+                'hostname': jsonobj['nodes'][nodeid]['host'],
+                'disk_free': jsonobj['nodes'][nodeid]['fs']['total']['free_in_bytes'] / (1024 * 1024 * 1024),
+                'disk_total': jsonobj['nodes'][nodeid]['fs']['total']['total_in_bytes'] / (1024 * 1024 * 1024),
+                'mem_heap_per': jsonobj['nodes'][nodeid]['jvm']['mem']['heap_used_percent'],
+                'cpu_usage': jsonobj['nodes'][nodeid]['os']['cpu_percent'],
+                'load': jsonobj['nodes'][nodeid]['os']['load_average']
+            })
+        except Exception as e:
+            #logger.error("exception %r appending ES node stats" %e)
+            continue
     return results