Thanks Vinay for reply
-----Original Message----- From: Vinayakumar B [mailto:vinayakum...@apache.org] Sent: 22 September 2014 PM 04:20 To: hdfs-dev@hadoop.apache.org Subject: Re: Issue with DN and NN connection. Hi Surendra, Since, both public and private IPs are in same subnet, DN machien choosing public interface to connect to NN, for which no mapping present in NN machine. Separate your IPs to different segments for private and public, then communication will happen through corresponding interface. Regards, Vinay Regards, Vinay On Mon, Sep 22, 2014 at 1:54 PM, Steve Loughran <ste...@hortonworks.com> wrote: > On 22 September 2014 08:02, surendra lilhore > <surendra.lilh...@huawei.com> > wrote: > > > org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException: > *Datanode > > denied communication with namenode because hostname cannot be > > resolved* (ip=10.18.0.108, hostname=10.18.0.108): > > DatanodeRegistration(10.18.0.117, > > datanodeUuid=0ed5012a-7ef6-4b55-b87b-fec70296faa3, infoPort=25002, > > ipcPort=50020, > > storageInfo=lv=-55;cid=myhacluster;nsid=1613974306;c=0) > > > > at > > > org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager.register > Datanode(DatanodeManager.java:806) > > > > at > > > org.apache.hadoop.hdfs.server.namenode.FSNamesystem.registerDatanode(F > SNamesystem.java:4313) > > > > > > > > 1. From a stack trace you are free to go back and work out what is > happening. > 2. By the look of things, It's happening in the NN, working out who > is calling it > > public void registerDatanode(DatanodeRegistration nodeReg) > throws DisallowedDatanodeException, UnresolvedTopologyException { > InetAddress dnAddress = *Server.getRemoteIp();* > > > As to why it's using the private IP over public, that's probably a > decision by the networking stack deciding which interface can get packets to > the NN. > > > > You do appear to be able to turn that check off: > > if (checkIpHostnameInRegistration && !isNameResolved(dnAddress)) { > ... > } > > which comes down to a configurable check: > > > public static final String > DFS_NAMENODE_DATANODE_REGISTRATION_IP_HOSTNAME_CHECK_KEY = > "dfs.namenode.datanode.registration.ip-hostname-check"; > public static final boolean > DFS_NAMENODE_DATANODE_REGISTRATION_IP_HOSTNAME_CHECK_DEFAULT = true; > > > try setting it to false and the check will be skipped. Be advised > though -the NN does appear to save the senders IP to use for the RPC > channel in future, so if the NN cannot reach the DN via the same IP > address that it registered on —you won't have a file system. > > I'd play with network settings, especially the routing options on your > floating vs VPN addresses. > > -- > CONFIDENTIALITY NOTICE > NOTICE: This message is intended for the use of the individual or > entity to which it is addressed and may contain information that is > confidential, privileged and exempt from disclosure under applicable > law. If the reader of this message is not the intended recipient, you > are hereby notified that any printing, copying, dissemination, > distribution, disclosure or forwarding of this communication is > strictly prohibited. If you have received this communication in error, > please contact the sender immediately and delete it from your system. Thank > You. >
