@Override
      public void fromData(DataInput in,
          DeserializationContext context) throws IOException, ClassNotFoundException {
        super.fromData(in, context);
        int flags = in.readByte();
        hasRegisteredInterest = (flags & HAS_REGISTERED_INTEREST_BIT) != 0;
        isPrimary = (flags & IS_PRIMARY_BIT) != 0;
      }
HARegions have their own advisors so that interest registration state can be tracked
geode-core/src/main/java/org/apache/geode/internal/cache/HARegion.java