Datanode principal Kerberos issue

[#1]

SYMPTOM: User has latest HDP integrated with kerberos.

While starting the datanode user gets the message: Login failure for dn/host1@EXAMPLE.NET from keytab /etc/security/keytabs/dn.service.keytab. But the principal is dn/host1.bc@EXAMPLE.NET

Where host1 is the hostname of the datanode host and

EXAMPLE.NET is the REALM name.

ERROR: The output of klist command is as below -

$klist -kt /etc/security/keytabs/dn.service.keytab 
Keytab name: FILE:/etc/security/keytabs/dn.service.keytab 
KVNO Timestamp Principal 
---- ------------------- ------------------------------------------------------ 
0 12/21/2016 10:38:13 dn/host1.bc@EXAMPLE.NET

In logs it shows - dn/host1@EXAMPLE.NET

Where as it should show - dn/host1.bc@EXAMPLE.NET

ROOT CAUSE: This is issue with entries in /etc/host file.

RESOLUTION: User has below entry in /etc/hosts file -

<ipaddress> <hostname> <FQDN> <FQDN> Now the order is changed to <ipaddress> <FQDN> <hostname> <FQDN>

Which resolved the issue.