kvm: Handle the failures when setting up memory balloon stats period for KVM VMs (#8049)

Author: harikrishna-patnala

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java

@@ -1313,8 +1313,8 @@ protected void setupMemoryBalloonStatsPeriod(Connect conn) {
                 }
                 s_logger.debug(String.format("The memory balloon stats period [%s] has been set successfully for the VM (Libvirt Domain) with ID [%s] and name [%s].",
                         currentVmBalloonStatsPeriod, vmId, dm.getName()));
-            } catch (final LibvirtException e) {
-                s_logger.warn("Failed to set up memory balloon stats period." + e.getMessage());
+            } catch (final Exception e) {
+                s_logger.warn(String.format("Failed to set up memory balloon stats period for the VM %s with exception %s", parser.getName(), e.getMessage()));
             }
         }
     }

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtDomainXMLParser.java

@@ -59,6 +59,8 @@ public class LibvirtDomainXMLParser {
     private Integer vncPort;
     private String desc;
 
+    private String name;
+
     public boolean parseDomainXML(String domXML) {
         DocumentBuilder builder;
         try {
@@ -71,6 +73,7 @@ public boolean parseDomainXML(String domXML) {
             Element rootElement = doc.getDocumentElement();
 
             desc = getTagValue("description", rootElement);
+            name = getTagValue("name", rootElement);
 
             Element devices = (Element)rootElement.getElementsByTagName("devices").item(0);
             NodeList disks = devices.getElementsByTagName("disk");
@@ -303,15 +306,19 @@ public boolean parseDomainXML(String domXML) {
                 String path = getTagValue("backend", rng);
                 String bytes = getAttrValue("rate", "bytes", rng);
                 String period = getAttrValue("rate", "period", rng);
-
-                if (StringUtils.isEmpty(backendModel)) {
-                    def = new RngDef(path, Integer.parseInt(bytes), Integer.parseInt(period));
+                if (StringUtils.isAnyEmpty(bytes, period)) {
+                    s_logger.debug(String.format("Bytes and period in the rng section should not be null, please check the VM %s", name));
                 } else {
-                    def = new RngDef(path, RngBackendModel.valueOf(backendModel.toUpperCase()),
-                                     Integer.parseInt(bytes), Integer.parseInt(period));
+                    if (StringUtils.isEmpty(backendModel)) {
+                        def = new RngDef(path, Integer.parseInt(bytes), Integer.parseInt(period));
+                    } else {
+                        def = new RngDef(path, RngBackendModel.valueOf(backendModel.toUpperCase()),
+                                Integer.parseInt(bytes), Integer.parseInt(period));
+                    }
+                }
+                if (def != null) {
+                    rngDefs.add(def);
                 }
-
-                rngDefs.add(def);
             }
 
             NodeList watchDogs = devices.getElementsByTagName("watchdog");
@@ -418,4 +425,8 @@ public List<WatchDogDef> getWatchDogs() {
     public String getDescription() {
         return desc;
     }
+
+    public String getName() {
+        return name;
+    }
 }