private void fetchResourceInformationFromHelix(String dcName) {
    HelixAdmin admin = adminForDc.get(dcName);
    Map<Integer, IdealState> resourceIdToIdealState = getIdealStateForAllResource(admin, dcName);
    TreeMap<Integer, Set<String>> resourceIdToInstances = getResourceNameToInstances(resourceIdToIdealState);
    Map<String, Set<Integer>> instanceToResourceIds = getInstanceToResourceIds(resourceIdToInstances);
    Map<String, Integer> partitionToResourceId = getPartitionToResourceId(resourceIdToIdealState);
    dcToResourceIdToIdealState.put(dcName, resourceIdToIdealState);
    dcToResourceIdToInstances.put(dcName, resourceIdToInstances);
    dcToInstanceToResourceIds.put(dcName, instanceToResourceIds);
    dcToPartitionToResourceId.put(dcName, partitionToResourceId);
  }
Return a map from partition to resource id, given the map from resource id to ideal state.
@param resourceIdToIdealState
@return
ambry-clustermap/src/main/java/com/github/ambry/clustermap/HelixBootstrapUpgradeUtil.java