private static boolean skipForSplit(final RegionState state, final RegionInfo regionInfo) {
    final String name = regionInfo.getEncodedName();
    return logTraceReason(() -> state == null,
      "skipping split of region {} because no state information is available.", name)
      || logTraceReason(() -> !Objects.equals(state.getState(), RegionState.State.OPEN),
        "skipping merge of region {} because it is not open.", name);
  }
Determine if a region in {@link RegionState} should be considered for a split operation.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java