@Override
  public void execute(FunctionContext context) {
    try {
      InternalCache cache = (InternalCache) context.getCache();
      DistributionConfig config = cache.getInternalDistributedSystem().getConfig();

      String bindAddress = RestAgent.getBindAddressForHttpService(config);

      final String protocolType = config.getHttpServiceSSLEnabled() ? "https" : "http";

      if (cache.isRESTServiceRunning()) {
        context.getResultSender()
            .lastResult(protocolType + "://" + bindAddress + ":" + config.getHttpServicePort());

      } else {
        context.getResultSender().lastResult("");
      }
    } catch (CacheClosedException ex) {
      context.getResultSender().lastResult("");
    }
  }
This property defines internal function that will get executed on each node to fetch active
REST service endpoints (servers).
geode-core/src/main/java/org/apache/geode/internal/cache/execute/util/FindRestEnabledServersFunction.java