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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.