Correção de erros de backup introduzidos na .6

Author: João Jandre

api/src/main/java/org/apache/cloudstack/backup/Backup.java

@@ -17,6 +17,7 @@
 
 package org.apache.cloudstack.backup;
 
+import java.io.Serializable;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
@@ -131,7 +132,7 @@ public void setBackupUuid(String backupUuid) {
         }
     }
 
-    class VolumeInfo {
+    class VolumeInfo implements Serializable {
         private String uuid;
         private Volume.Type type;
         private Long size;

server/src/main/java/org/apache/cloudstack/backup/BackupCompressionService.java

@@ -222,11 +222,19 @@ private void rescheduleLostJobs() {
             logger.debug("Searching lost compression jobs to reschedule in zone [{}].", dataCenterVO.getUuid());
             for (ClusterVO clusterVO : clusterDao.listByDcHyType(dataCenterVO.getId(), Hypervisor.HypervisorType.KVM.toString())) {
                 List<HostVO> hostVOS = hostDao.findRoutingByClusterId(clusterVO.getId());
+                if (hostVOS.isEmpty()) {
+                    logger.debug("No hosts found in cluster [{}]. Cannot reschedule jobs for it.", clusterVO.getUuid());
+                    continue;
+                }
                 Calendar date = Calendar.getInstance();
                 date.add(Calendar.SECOND, (int)Math.round(NativeBackupProvider.backupCompressionTimeout.valueIn(clusterVO.getId()) * -RESCHEDULE_TO_TIMEOUT_RATIO));
                 List<BackupCompressionJobVO> lostJobs = backupCompressionJobDao.listExecutingJobsByHostsAndStartTimeBefore(hostVOS.stream().map(HostVO::getId).toArray(),
                         date.getTime());
-                logger.debug("Found [{}] jobs to reschedule. Processing them as failures and rescheduling them.", lostJobs.size());
+                if (lostJobs.isEmpty()) {
+                    logger.debug("Found no compression jobs to reschedule for cluster [{}].", clusterVO.getUuid());
+                    continue;
+                }
+                logger.debug("Found [{}] compression jobs to reschedule for cluster [{}]. Processing them as failures and rescheduling them.", lostJobs.size(), clusterVO.getUuid());
                 lostJobs.forEach(job -> processJobResult(job, false));
             }
         }