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Eli Collins commented on HDFS-3150: ----------------------------------- These new options are distinct from hadoop.security.token.service.use_ip, it would be reasonable to have them set to true and use_ip to false and vice versa. Note that these only affect client -> DN and DN -> DN where use_ip is Client -> NN. There's really not much overlap. > Add option for clients to contact DNs via hostname > -------------------------------------------------- > > Key: HDFS-3150 > URL: https://issues.apache.org/jira/browse/HDFS-3150 > Project: Hadoop HDFS > Issue Type: New Feature > Components: data-node, hdfs client > Affects Versions: 1.0.0, 2.0.0-alpha > Reporter: Eli Collins > Assignee: Eli Collins > Fix For: 1.1.0 > > Attachments: hdfs-3150-b1.txt, hdfs-3150-b1.txt, hdfs-3150.txt, > hdfs-3150.txt, hdfs-3150.txt, hdfs-3150.txt > > > The DN listens on multiple IP addresses (the default {{dfs.datanode.address}} > is the wildcard) however per HADOOP-6867 only the source address (IP) of the > registration is given to clients. HADOOP-985 made clients access datanodes by > IP primarily to avoid the latency of a DNS lookup, this had the side effect > of breaking DN multihoming (the client can not route the IP exposed by the NN > if the DN registers with an interface that has a cluster-private IP). To fix > this let's add back the option for Datanodes to be accessed by hostname. > This can be done by: > # Modifying the primary field of the Datanode descriptor to be the hostname, > or > # Modifying Client/Datanode <-> Datanode access use the hostname field > instead of the IP > Approach #2 does not require an incompatible client protocol change, and is > much less invasive. It minimizes the scope of modification to just places > where clients and Datanodes connect, vs changing all uses of Datanode > identifiers. > New client and Datanode configuration options are introduced: > - {{dfs.client.use.datanode.hostname}} indicates all client to datanode > connections should use the datanode hostname (as clients outside cluster may > not be able to route the IP) > - {{dfs.datanode.use.datanode.hostname}} indicates whether Datanodes should > use hostnames when connecting to other Datanodes for data transfer > If the configuration options are not used, there is no change in the current > behavior. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira