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MapReduce >> mail # user >> Re: Namenode going to safe mode on YARN


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Nitin Pawar 2013-05-06, 12:03
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Re: Namenode going to safe mode on YARN
Hi Kishore,

It should not be a bug. After restarting HDFS, namenode will enter safe
mode until all needed data is collected. During safe mode, all update
operations will fail.

In some cases, as Nitin mentioned, namenode will never leave safe mode
because it can't get enough data. In that case you may need to force name
node leave safe mode.

For more information, see
http://hadoop.apache.org/docs/r2.0.4-alpha/hadoop-project-dist/hadoop-hdfs/HdfsUserGuide.html#Safemode
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On Mon, May 6, 2013 at 5:00 PM, Nitin Pawar <[EMAIL PROTECTED]> wrote:

> What is your replication factor on hdfs?
> Did any of your datanode go down recently and is not back in rotation?
> Did you delete any hdfs blocks directly from datanodes?
> On May 6, 2013 2:28 PM, "Krishna Kishore Bonagiri" <
> [EMAIL PROTECTED]> wrote:
>
>> Hi,
>>
>>   I have been running application on my YARN cluster since around 20
>> days, about 5000 applications a day. I am getting the following error
>> today. Please let me know how can I avoid this, is this happening because
>> of a bug?
>>
>> org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.namenode.SafeModeException):
>> Cannot create file/1066/AppMaster.jar. Name node is in safe mode.
>> The reported blocks 4775 needs additional 880 blocks to reach the
>> threshold 0.9990 of total blocks 5660. Safe mode will be turned off
>> automatically.
>>         at
>> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFileInternal(FSNamesystem.java:1786)
>>         at
>> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFileInt(FSNamesystem.java:1737)
>>         at
>> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFile(FSNamesystem.java:1719)
>>         at
>> org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.create(NameNodeRpcServer.java:429)
>>          at
>> org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.create(ClientNamenodeProtocolServerSideTranslatorPB.java:271)
>>         at
>> org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java:40732)
>>         at
>> org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:454)
>>         at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1014)
>>         at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1741)
>>         at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1737)
>>         at java.security.AccessController.doPrivileged(Native Method)
>>         at javax.security.auth.Subject.doAs(Subject.java:415)
>>         at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1478)
>>         at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1735)
>>
>>
>> Thanks,
>> Kishore
>>
>
--
Regards,
Ted Xu
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Krishna Kishore Bonagiri 2013-05-06, 11:59