[ https://issues.apache.org/jira/browse/HADOOP-985?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
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? -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.