code: public static void setLocalDirStickyBit(String dir) {
      try {
        // Support for sticky bit is platform specific. Check if the path starts with "/" and if so,
        // assume that the host supports the chmod command.
        if (dir.startsWith(AlluxioURI.SEPARATOR)) {
          // TODO(peis): This is very slow. Consider removing this.
          Runtime.getRuntime().exec("chmod +t " + dir);
        }
      } catch (IOException e) {
        LOG.info("Can not set the sticky bit of the directory: {}", dir, e);
      }
    }
docs: Sticky bit can be set primarily on directories in UNIX / Linux.
  
  If the sticky bit of is enabled on a directory, only the owner and the root user can delete /
  rename the files or directories within that directory. No one else can delete other users data
  in this directory(Where sticky bit is set).
  
  This is a security measure to avoid deletion of folders and their content (sub-folders and
  files), though other users have full permissions.
  
  Setting the sticky bit of a file is a no-op.
  
  @param dir absolute dir path to set the sticky bit