Program: 115463
Project: 115463
Buggy source:
private boolean doProcess(ClusterInstanceActivatedEvent event,Topology topology){
  String applicationId=event.getAppId();
  String serviceName=event.getServiceName();
  String clusterId=event.getClusterId();
  if (TopologyApplicationFilter.apply(applicationId)) {
    return false;
  }
  if (TopologyServiceFilter.apply(serviceName)) {
    return false;
  }
  if (TopologyClusterFilter.apply(clusterId)) {
    return false;
  }
  Service service=topology.getService(event.getServiceName());
  if (service == null) {
    if (log.isWarnEnabled()) {
      log.warn(String.format("String_Node_Str",event.getServiceName()));
    }
    return false;
  }
  Cluster cluster=service.getCluster(event.getClusterId());
  if (cluster == null) {
    if (log.isDebugEnabled()) {
      log.debug(String.format("String_Node_Str",event.getServiceName(),event.getClusterId()));
      return false;
    }
  }
 else {
    cluster.addAccessUrlList(event.getInstanceId(),event.getAccessUrls());
    cluster.addLoadBalancerIps(event.getLoadBalancerIps());
    ClusterInstance context=cluster.getInstanceContexts(event.getInstanceId());
    if (context == null) {
      log.warn("String_Node_Str" + event.getClusterId() + "String_Node_Str"+ event.getInstanceId());
      return false;
    }
    ClusterStatus status=ClusterStatus.Active;
    if (!context.isStateTransitionValid(status)) {
      log.error("String_Node_Str" + context.getStatus() + "String_Node_Str"+ status);
    }
    context.setStatus(status);
  }
  notifyEventListeners(event);
  return true;
}

Fixed version (ground truth):
private boolean doProcess(ClusterInstanceActivatedEvent event,Topology topology){
  String applicationId=event.getAppId();
  String serviceName=event.getServiceName();
  String clusterId=event.getClusterId();
  if (TopologyApplicationFilter.apply(applicationId)) {
    return false;
  }
  if (TopologyServiceFilter.apply(serviceName)) {
    return false;
  }
  if (TopologyClusterFilter.apply(clusterId)) {
    return false;
  }
  Service service=topology.getService(event.getServiceName());
  if (service == null) {
    if (log.isWarnEnabled()) {
      log.warn(String.format("String_Node_Str",event.getServiceName()));
    }
    return false;
  }
  Cluster cluster=service.getCluster(event.getClusterId());
  if (cluster == null) {
    if (log.isDebugEnabled()) {
      log.debug(String.format("String_Node_Str",event.getServiceName(),event.getClusterId()));
      return false;
    }
  }
 else {
    ClusterInstance clusterInstance=cluster.getInstanceContexts(event.getInstanceId());
    if (clusterInstance == null) {
      log.warn(String.format("String_Node_Str",event.getAppId(),event.getClusterId(),event.getInstanceId()));
      return false;
    }
    if (clusterInstance.getStatus() == ClusterStatus.Active) {
      log.debug(String.format("String_Node_Str" + "String_Node_Str",event.getAppId(),event.getClusterId(),event.getInstanceId()));
    }
 else {
      cluster.addAccessUrlList(event.getInstanceId(),event.getAccessUrls());
      if ((event.getLoadBalancerIps() != null) && (event.getLoadBalancerIps().size() > 0)) {
        cluster.setLoadBalancerIps(event.getLoadBalancerIps());
      }
      ClusterStatus status=ClusterStatus.Active;
      if (!clusterInstance.isStateTransitionValid(status)) {
        log.error("String_Node_Str" + clusterInstance.getStatus() + "String_Node_Str"+ status);
      }
      clusterInstance.setStatus(status);
    }
  }
  notifyEventListeners(event);
  return true;
}