[ 
https://issues.apache.org/jira/browse/HADOOP-3426?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Steve Loughran updated HADOOP-3426:
-----------------------------------

    Attachment: hadoop-3426.patch

This is the latest patch; works well on my networks and caches the local 
hostname and IPAddress only. 

> Datanode does not start up if the local machines DNS isnt working right and 
> dfs.datanode.dns.interface==default
> ---------------------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-3426
>                 URL: https://issues.apache.org/jira/browse/HADOOP-3426
>             Project: Hadoop Core
>          Issue Type: Bug
>          Components: dfs
>    Affects Versions: 0.19.0
>         Environment: Ubuntu 8.04, at home, no reverse DNS
>            Reporter: Steve Loughran
>            Assignee: Steve Loughran
>            Priority: Minor
>         Attachments: hadoop-3426.patch, hadoop-3426.patch, hadoop-3426.patch
>
>
> This is the third Java project I've been involved in that doesnt work on my 
> home network, due to implementation issues with  
> java.net.InetAddress.getLocalHost(), issues that only show up on an unamanged 
> network. Fortunately my home network exists to find these problems early.
> In hadoop, if the local hostname doesnt resolve, the datanode does not start 
> up:
> Caused by: java.net.UnknownHostException: k2: k2
> at java.net.InetAddress.getLocalHost(InetAddress.java:1353)
> at org.apache.hadoop.net.DNS.getDefaultHost(DNS.java:185)
> at org.apache.hadoop.dfs.DataNode.startDataNode(DataNode.java:184)
> at org.apache.hadoop.dfs.DataNode.(DataNode.java:162)
> at org.apache.hadoop.dfs.ExtDataNode.(ExtDataNode.java:55)
> at 
> org.smartfrog.services.hadoop.components.datanode.DatanodeImpl.sfStart(DatanodeImpl.java:60)
> While this is a valid option in a production (non-virtual) cluster, if you 
> are playing with VMWare/Xen private networks or on a home network, you can't 
> rely on DNS. 
> 1. In these situations, its usually better to fall back to using "localhost" 
> or 127.0.0.1 as a hostname if Java can't work it out for itself,
> 2. Its often good to cache this if used in lots of parts of the system, 
> otherwise the 30s timeouts can cause problems of their own.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to