This configuration parameter specifies, in hours, how often to renew the Kerberos credentials stored in the cache for users who have logged on successfully. Because Kerberos tickets expire after a set period of time, you can use this configuration parameter to periodically renew the existing Kerberos ticket to keep existing credentials valid.
In most cases, you set this configuration parameter using group policy. You can, however, set it manually in the configuration file if you are not using group policy or want to temporarily override group policy.
If you are manually setting this parameter, the parameter value must be a positive integer. A value of zero disables renewal. For example, to set the renewal interval to 8 hours:
krb5.cache.renew.interval = 8
If this parameter is not defined in the configuration file, its default value is 4 hours. The default value of 4 hours allows two attempts at renewal over a typical Kerberos ticket lifespan of 10 hours. If possible, you should allow enough time for at least two renewal attempts if you reset the value to something other than the 4-hour default.