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How to Troubleshoot Name Resolution Check Failures on BDA V4.1 and Higher Clusters (Doc ID 2029779.1)

Last updated on DECEMBER 28, 2020

Applies to:

Big Data Appliance Integrated Software - Version 3.1.0 and later
Linux x86-64

Purpose

NOTE: In the examples that follow, user details, cluster names, hostnames, directory paths, filenames, etc. represent a fictitious sample (and are used to provide an illustrative example only). Any similarity to actual persons, or entities, living or dead, is purely coincidental and not intended in any manner.

  

How to troubleshoot name resolution failures on the BDA when raised by the Cloudera Manager (CM) Host Inspector or the BDA utilities bdachecknet or bdacheckcluster. Name resolution failures can prevent the cluster from starting in Cloudera Manager. 

Consider an example of name resolution failures from the Host Inspector in CM preventing the cluster from starting when troubleshooting name resolution is required.  Navigate to: Hosts > Host Inspector > Show Inspector Results  and see a DNS lookup failure (both forward and reverse) for the hostname on Node 1 on all cluster nodes except Node 1.

Forward and reverse DNS lookup failure for hostname on Node 1 on all nodes except 1:


   DNS lookup of host bdanode01.example.com on host bdanode02.example.com failed. Expected <clientIP host1> but got <privateIP host1>.
   DNS reverse lookup of IP <clientIP host1> on host bdanode02.example.com failed. Expected bdanode01.example.com but got <clientIP host1>.
   ...
   DNS lookup of host bdanode01.example.com on host bdanode0n.example.com failed. Expected <clientIP host1> but got <privateIP host1>.
   DNS reverse lookup of IP <clientIP host1> on host bdanode0n.example.com failed. Expected bdanode01.example.com but got <clientIP host1>.


The same DNS lookup failures can be confirmed manually. 
1. Manually test the forward DNS lookup to verify that the domain name resolves to the correct IP address from node2.  In this case:  'nslookup bdanode01.example.com' does not return correct IP address.

2. Manually test the reverse DNS lookup to verify that the  IP adddress lookup does not resolve to the correct domain name from node 2.  In this case 'nslookup <node 1 ip>' does not return the correct hostname.

Troubleshooting Steps

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In this Document
Purpose
Troubleshooting Steps
 Background Information
 Troubleshooting Steps
References


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