Fix issue with allocator not considering subsequent clusters (apache#10603)

* Fix issue with allocator not considering subsequent clusters

* add missing return

* remove unused import

* update as per inputs

Author: Pearl1594

plugins/host-allocators/random/src/main/java/com/cloud/agent/manager/allocator/impl/RandomAllocator.java

@@ -94,15 +94,17 @@ private List<Host> findSuitableHosts(VirtualMachineProfile vmProfile, Deployment
             return suitableHosts;
         }
         String offeringHostTag = offering.getHostTag();
+
         VMTemplateVO template = (VMTemplateVO)vmProfile.getTemplate();
         String templateTag = template.getTemplateTag();
         String hostTag = null;
-        if (ObjectUtils.anyNull(offeringHostTag, templateTag)) {
-            hostTag = offeringHostTag;
-            hostTag = hostTag == null ? templateTag : String.format("%s, %s", hostTag, templateTag);
-            logger.debug(String.format("Looking for hosts in dc [%s], pod [%s], cluster [%s] and complying with host tag(s): [%s]", dcId, podId, clusterId, hostTag));
+        if (ObjectUtils.anyNotNull(offeringHostTag, templateTag)) {
+            hostTag = ObjectUtils.allNotNull(offeringHostTag, templateTag) ?
+                    String.format("%s, %s", offeringHostTag, templateTag) :
+                    ObjectUtils.firstNonNull(offeringHostTag, templateTag);
+            logger.debug("Looking for hosts in dc [{}], pod [{}], cluster [{}] and complying with host tag(s): [{}]", dcId, podId, clusterId, hostTag);
         } else {
-            logger.debug("Looking for hosts in dc: " + dcId + "  pod:" + podId + "  cluster:" + clusterId);
+            logger.debug("Looking for hosts in dc: {} pod: {} cluster: {}", dcId , podId, clusterId);
         }
         if (hosts != null) {
             // retain all computing hosts, regardless of whether they support routing...it's random after all

server/src/main/java/com/cloud/agent/manager/allocator/impl/FirstFitAllocator.java

@@ -25,7 +25,6 @@
 import javax.inject.Inject;
 import javax.naming.ConfigurationException;
 
-import com.cloud.utils.exception.CloudRuntimeException;
 import org.apache.cloudstack.framework.config.dao.ConfigurationDao;
 import org.apache.cloudstack.utils.reflectiontostringbuilderutils.ReflectionToStringBuilderUtils;
 import org.springframework.stereotype.Component;
@@ -137,8 +136,8 @@ public List<Host> allocateTo(VirtualMachineProfile vmProfile, DeploymentPlan pla
             // FirstFitAllocator should be used for user VMs only since it won't care whether the host is capable of routing or not
             return new ArrayList<>();
         }
-
-        logger.debug("Looking for hosts in zone [{}], pod [{}], cluster [{}]", dcId, podId, clusterId);
+        String paramAsStringToLog = String.format("zone [%s], pod [%s], cluster [%s]", dcId, podId, clusterId);
+        logger.debug("Looking for hosts in {}", paramAsStringToLog);
 
         String hostTagOnOffering = offering.getHostTag();
         String hostTagOnTemplate = template.getTemplateTag();
@@ -221,8 +220,8 @@ public List<Host> allocateTo(VirtualMachineProfile vmProfile, DeploymentPlan pla
 
 
         if (clusterHosts.isEmpty()) {
-            logger.error("No suitable host found for vm [{}] with tags [{}].", vmProfile, hostTagOnOffering);
-            throw new CloudRuntimeException(String.format("No suitable host found for vm [%s].", vmProfile));
+            logger.warn("No suitable host found for VM [{}] with tags {} in {}.", vmProfile, hostTagOnOffering, paramAsStringToLog);
+            return null;
         }
         // add all hosts that we are not considering to the avoid list
         List<HostVO> allhostsInCluster = _hostDao.listAllUpAndEnabledNonHAHosts(type, clusterId, podId, dcId, null);