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https://issues.apache.org/jira/browse/HADOOP-985?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Doug Cutting updated HADOOP-985:
--------------------------------

    Status: Open  (was: Patch Available)

This patch no longer applies to the current trunk.  Can you please update it?  
Thanks!

> Namenode should identify DataNodes as ip:port instead of hostname:port
> ----------------------------------------------------------------------
>
>                 Key: HADOOP-985
>                 URL: https://issues.apache.org/jira/browse/HADOOP-985
>             Project: Hadoop
>          Issue Type: Improvement
>          Components: dfs
>    Affects Versions: 0.11.0
>            Reporter: Raghu Angadi
>         Assigned To: Raghu Angadi
>             Fix For: 0.12.0
>
>         Attachments: dfshealth.html, HADOOP-985-1.patch, HADOOP-985-2.patch, 
> HADOOP-985-3.patch, HADOOP-985-4.patch, HADOOP-985-5.patch
>
>
> Right now NameNode keeps track of DataNodes with "hostname:port". One 
> proposal is to keep track of datanodes with "ip:port". There are various 
> concerns expressed regd hostnames and ip. Please add your experiences here so 
> that we have better idea on what we should fix etc.
> How should be calculate datanode ip: 
>             1) Just like how we calculate hostname currently with 
> "dfs.datanode.dns.interface" and "dfs.datanode.dns.nameserver". So if 
> interface specified wrong, it could report ip like 127.0.0.1 which might or 
> might not be intended.
>             2) Namenode can use the remove socket address when the datanode 
> registers. Not sure how easy it to get this address in RPC or if this is 
> desirable.
>             3) Namenode could just resolve the hostname when a datanode 
> registers. It could print of a warning if the resolved ip and reported ip 
> don't match.
> One advantage of using IPs is that DFSClient does not need to resolve them 
> when it connects to datanode. This could save few milliseconds for each 
> block. Also, DFSClient should check all its ips to see if a given ip is local 
> or not.
> As far I see namenode does not resolve any DNS in normal operations since it 
> does not actively contact datanodes. In that sense not sure if this have any 
> change in Namenode performance.
> Thoughts?

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