Program: 116168
Project: 116168
Buggy source:
@Override protected void onEvent(Event event){
  ClusterInstanceCreatedEvent clusterInstanceCreatedEvent=(ClusterInstanceCreatedEvent)event;
  AbstractClusterMonitor clusterMonitor=AutoscalerContext.getInstance().getClusterMonitor(clusterInstanceCreatedEvent.getClusterId());
  String instanceId=((ClusterInstanceCreatedEvent)event).getInstanceId();
  if (clusterMonitor != null) {
    TopologyManager.acquireReadLockForCluster(clusterInstanceCreatedEvent.getServiceName(),clusterInstanceCreatedEvent.getClusterId());
    try {
      Service service=TopologyManager.getTopology().getService(clusterInstanceCreatedEvent.getServiceName());
      if (service != null) {
        Cluster cluster=service.getCluster(clusterInstanceCreatedEvent.getClusterId());
        if (cluster != null) {
          try {
            if (cluster.isKubernetesCluster()) {
              clusterMonitor.setClusterContext(ClusterContextFactory.getKubernetesClusterContext(instanceId,cluster));
            }
 else {
              VMClusterContext clusterContext=(VMClusterContext)clusterMonitor.getClusterContext();
              if (clusterContext == null) {
                clusterContext=ClusterContextFactory.getVMClusterContext(instanceId,cluster);
                clusterMonitor.setClusterContext(clusterContext);
              }
              clusterContext.addInstanceContext(instanceId,cluster);
              if (clusterMonitor.getInstance(instanceId) == null) {
                ClusterInstance clusterInstance=cluster.getInstanceContexts(instanceId);
                ClusterInstance instance=new ClusterInstance(clusterInstance.getAlias(),cluster.getClusterId(),clusterInstance.getInstanceId());
                instance.setParentId(clusterInstance.getParentId());
                instance.setNetworkPartitionId(clusterInstance.getNetworkPartitionId());
                instance.setPartitionId(clusterInstance.getPartitionId());
                instance.setStatus(clusterInstance.getStatus());
                clusterMonitor.addInstance(instance);
              }
            }
            if (clusterMonitor.hasMonitoringStarted().compareAndSet(false,true)) {
              clusterMonitor.startScheduler();
              log.info("String_Node_Str" + clusterInstanceCreatedEvent.getClusterId() + "String_Node_Str");
            }
          }
 catch (          PolicyValidationException e) {
            log.error(e.getMessage(),e);
          }
catch (          PartitionValidationException e) {
            log.error(e.getMessage(),e);
          }
        }
      }
 else {
        log.error("String_Node_Str" + clusterInstanceCreatedEvent.getServiceName() + "String_Node_Str"+ clusterInstanceCreatedEvent.getClusterId());
      }
    }
  finally {
      TopologyManager.releaseReadLockForCluster(clusterInstanceCreatedEvent.getServiceName(),clusterInstanceCreatedEvent.getClusterId());
    }
  }
 else {
    log.error("String_Node_Str" + clusterInstanceCreatedEvent.getClusterId());
  }
}

Fixed version (ground truth):
@Override protected void onEvent(Event event){
  ClusterInstanceCreatedEvent clusterInstanceCreatedEvent=(ClusterInstanceCreatedEvent)event;
  AbstractClusterMonitor clusterMonitor=AutoscalerContext.getInstance().getClusterMonitor(clusterInstanceCreatedEvent.getClusterId());
  ClusterInstance clusterInstance=((ClusterInstanceCreatedEvent)event).getClusterInstance();
  String instanceId=clusterInstance.getInstanceId();
  if (clusterMonitor != null) {
    TopologyManager.acquireReadLockForCluster(clusterInstanceCreatedEvent.getServiceName(),clusterInstanceCreatedEvent.getClusterId());
    try {
      Service service=TopologyManager.getTopology().getService(clusterInstanceCreatedEvent.getServiceName());
      if (service != null) {
        Cluster cluster=service.getCluster(clusterInstanceCreatedEvent.getClusterId());
        if (cluster != null) {
          try {
            if (cluster.isKubernetesCluster()) {
              clusterMonitor.setClusterContext(ClusterContextFactory.getKubernetesClusterContext(instanceId,cluster));
            }
 else {
              VMClusterContext clusterContext=(VMClusterContext)clusterMonitor.getClusterContext();
              if (clusterContext == null) {
                clusterContext=ClusterContextFactory.getVMClusterContext(instanceId,cluster);
                clusterMonitor.setClusterContext(clusterContext);
              }
              clusterContext.addInstanceContext(instanceId,cluster);
              if (clusterMonitor.getInstance(instanceId) == null) {
                ClusterInstance clusterInstance1=cluster.getInstanceContexts(instanceId);
                clusterMonitor.addInstance(clusterInstance1);
              }
            }
            if (clusterMonitor.hasMonitoringStarted().compareAndSet(false,true)) {
              clusterMonitor.startScheduler();
              log.info("String_Node_Str" + clusterInstanceCreatedEvent.getClusterId() + "String_Node_Str");
            }
          }
 catch (          PolicyValidationException e) {
            log.error(e.getMessage(),e);
          }
catch (          PartitionValidationException e) {
            log.error(e.getMessage(),e);
          }
        }
      }
 else {
        log.error("String_Node_Str" + clusterInstanceCreatedEvent.getServiceName() + "String_Node_Str"+ clusterInstanceCreatedEvent.getClusterId());
      }
    }
  finally {
      TopologyManager.releaseReadLockForCluster(clusterInstanceCreatedEvent.getServiceName(),clusterInstanceCreatedEvent.getClusterId());
    }
  }
 else {
    log.error("String_Node_Str" + clusterInstanceCreatedEvent.getClusterId());
  }
}