public static String read(String filename) {
      String result = AccessController.doPrivileged(new PrivilegedAction<String>() {
        @Override
        public String run() {
          String fileString = null;
          try {
            fileString = new String(Files.readAllBytes(Paths.get(filename)), StandardCharsets.UTF_8);
          } catch (Exception e) {
            LOG.warn("Unable to read file: {}", filename, e);
          }
          return fileString;
        }
      });
      return result;
    }
A servlet to print system specific configurations that are not exposed via JMX.
Currently it exposes
- kernel configs
- network configs
- memory configs

/system?refresh=true will run sysctl command again
llap-server/src/java/org/apache/hadoop/hive/llap/daemon/services/impl/SystemConfigurationServlet.java