public List<Map<String, Object>> getAllVisibleRegionNames() {
		if (config.isClustered()) {
			return allRegionNames.get().stream().map(region -> {
				Map<String, Object> regionInfo = new HashMap<>();
				String subregionAttributes = region.get(SUBREGION_ATTR_KEY);
				regionInfo.put(REGION_ATTR_KEY, region.get(REGION_ATTR_KEY));
				regionInfo.put(SUBREGION_ATTR_KEY, convertSubregionsStringToSet(subregionAttributes));
				return regionInfo;
			}).collect(toList());
		} else {
			return emptyList();
		}
	}
Get region list of all clustered controller.

@return region list
ngrinder-controller/src/main/java/org/ngrinder/region/service/RegionService.java