Help Center> MapReduce Service> User Guide (Kuala Lumpur Region)> FAQs> Kerberos Usage> How Do I Prevent Kerberos Authentication Expiration?
Updated on 2022-08-12 GMT+08:00

How Do I Prevent Kerberos Authentication Expiration?

  • Java applications:

    Before connecting to HBase, HDFS, or other big data components, call loginUserFromKeytab() to create a UGI. Then, start a scheduled thread to periodically check whether the Kerberos Authentication expires. Log in to the system again before the Kerberos Authentication expires.

    private static void startCheckKeytabTgtAndReloginJob() {
    //The credential is checked every 10 minutes, and updated before the expiration time.
            ThreadPool.updateConfigThread.scheduleWithFixedDelay(() -> {
                try {
                    UserGroupInformation.getLoginUser().checkTGTAndReloginFromKeytab();
                    logger.warn("get tgt:{}", UserGroupInformation.getLoginUser().getTGT());
                    logger.warn("Check Kerberos Tgt And Relogin From Keytab Finish.");
                } catch (IOException e) {
                    logger.error("Check Kerberos Tgt And Relogin From Keytab Error", e);
                }
            }, 0, 10, TimeUnit.MINUTES);
            logger.warn("Start Check Keytab TGT And Relogin Job Success.");
        }
  • Tasks executed in shell mode:
    1. Run the kinit command to authenticate the user.
    2. Create a scheduled task of the operating system or any other scheduled task to run the kinit command to authenticate the user periodically.
    3. Submit jobs to execute big data tasks.
  • Spark jobs:

    If you submit jobs using spark-shell, spark-submit, or spark-sql, you can specify Keytab and Principal in the command to perform authentication and periodically update the login credential and authorization tokens to prevent authentication expiration.

    Example:

    spark-shell --principal spark2x/hadoop.<System domain name>@<System domain name> --keytab ${BIGDATA_HOME}/FusionInsight_Spark2x_8.1.0.1/install/FusionInsight-Spark2x-2.4.5/keytab/spark2x/SparkResource/spark2x.keytab --master yarn