Greenplum External Queries fail with "javax.security.auth.login.LoginException: connect timed out"

Products

• VMware Tanzu Greenplum

Issue/Introduction

Symptoms:
Greenplum External queries are failing. 

The Greenplum Master log or Segment logs show the following during failed external queries to a Hadoop platform:

Exception in thread ""main"" java.io.IOException: Login failure for gpadmin/[email protected] from keytab /home/gpadmin/gpadmin.hadoop.keytab: javax.security.auth.login.LoginException: connect timed out
        at org.apache.hadoop.security.UserGroupInformation.loginUserFromKeytab(UserGroupInformation.java:987)

Environment

Cause

When Kerberos security is enabled, this can occur when there are issues communicating with the Kerberos KDC host(s) configured in the /etc/krb5.conf on the segment hosts. The issues can be network related or related to resource issues on the remote Kerberos KDC host itself.

Resolution

This can happen if the /var/log file system on the Kerberos KDC host fills up.  Amongst other things, you should also look for issues on the remote Kerberos KDC server host, such as:

- Issues with KDC file systems, logging, etc
- Available memory
- Available CPU
- Load
- Socket connections
- Kerberos settings