protected void initReconfigurable(Configuration confToLoad) {
    this.allowFallbackToSimpleAuth = confToLoad.getBoolean(FALLBACK_TO_INSECURE_CLIENT_AUTH, false);
    if (isSecurityEnabled && allowFallbackToSimpleAuth) {
      LOG.warn("********* WARNING! *********");
      LOG.warn("This server is configured to allow connections from INSECURE clients");
      LOG.warn("(" + FALLBACK_TO_INSECURE_CLIENT_AUTH + " = true).");
      LOG.warn("While this option is enabled, client identities cannot be secured, and user");
      LOG.warn("impersonation is possible!");
      LOG.warn("For secure operation, please disable SIMPLE authentication as soon as possible,");
      LOG.warn("by setting " + FALLBACK_TO_INSECURE_CLIENT_AUTH + " = false in hbase-site.xml");
      LOG.warn("****************************");
    }
  }
Constructs a server listening on the named port and address.
@param server           hosting instance of {@link Server}. We will do authentications if an
                        instance else pass null for no authentication check.
@param name             Used keying this rpc servers' metrics and for naming the Listener
                        thread.
@param services         A list of services.
@param bindAddress      Where to listen
@param reservoirEnabled Enable ByteBufferPool or not.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java