public static boolean siblingNodesActiveReplicaCheck()

in helix-core/src/main/java/org/apache/helix/util/InstanceValidationUtil.java [417:477]
55 lines of code
18 McCabe index (conditional complexity)

  public static boolean siblingNodesActiveReplicaCheck(HelixDataAccessor dataAccessor,
      String instanceName, Set<String> toBeStoppedInstances) {
    PropertyKey.Builder propertyKeyBuilder = dataAccessor.keyBuilder();
    List<String> resources = dataAccessor.getChildNames(propertyKeyBuilder.idealStates());

    for (String resourceName : resources) {
      IdealState idealState = dataAccessor.getProperty(propertyKeyBuilder.idealStates(resourceName));
      if (idealState == null || !idealState.isEnabled() || !idealState.isValid()
          || TaskConstants.STATE_MODEL_NAME.equals(idealState.getStateModelDefRef())) {
        continue;
      }
      ExternalView externalView =
          dataAccessor.getProperty(propertyKeyBuilder.externalView(resourceName));
      if (externalView == null) {
        throw new HelixException(
            String.format("Resource %s does not have external view!", resourceName));
      }
      // Get the minActiveReplicas constraint for the resource
      int minActiveReplicas = externalView.getMinActiveReplicas();
      if (minActiveReplicas == -1) {
        _logger.warn("Resource {} is missing minActiveReplica field. Skip the sibling check",
            resourceName);
        continue;
      }
      String stateModeDef = externalView.getStateModelDefRef();
      StateModelDefinition stateModelDefinition =
          dataAccessor.getProperty(propertyKeyBuilder.stateModelDef(stateModeDef));
      Set<String> unhealthyStates = new HashSet<>(UNHEALTHY_STATES);
      if (stateModelDefinition != null) {
        unhealthyStates.add(stateModelDefinition.getInitialState());
      }
      for (String partition : externalView.getPartitionSet()) {
        Map<String, String> stateByInstanceMap = externalView.getStateMap(partition);
        // found the resource hosted on the instance
        if (stateByInstanceMap.containsKey(instanceName)) {
          // If this node's replica is in unhealthy state, skip the sibling check as removing this replica will not
          // negatively affect availability.
          if (unhealthyStates.contains(stateByInstanceMap.get(instanceName))) {
            continue;
          }
          int numHealthySiblings = 0;
          for (Map.Entry<String, String> entry : stateByInstanceMap.entrySet()) {
            String siblingInstanceName = entry.getKey();
            if (!siblingInstanceName.equals(instanceName) && (toBeStoppedInstances == null
                || !toBeStoppedInstances.contains(siblingInstanceName))
                && !unhealthyStates.contains(entry.getValue())) {
              numHealthySiblings++;
            }
          }
          if (numHealthySiblings < minActiveReplicas) {
            _logger.info(
                "Partition {} doesn't have enough active replicas in sibling nodes. NumHealthySiblings: {}, minActiveReplicas: {}",
                partition, numHealthySiblings, minActiveReplicas);
            return false;
          }
        }
      }
    }

    return true;
  }