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HDFS >> mail # user >> Re: High Availability - second namenode (master2) issue: Incompatible namespaceIDs


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hadoop hive 2012-11-16, 07:45
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Re: High Availability - second namenode (master2) issue: Incompatible namespaceIDs
Delete the VERSION for the datanode before format.


Shashwat Shriparv
On Fri, Nov 16, 2012 at 1:15 PM, hadoop hive <[EMAIL PROTECTED]> wrote:

> Seems like you havn't format your cluster (if its 1st time made).
>
> On Fri, Nov 16, 2012 at 9:58 AM, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>
>> Hi,
>>
>> Please help!
>>
>> I have installed a Hadoop Cluster with a single master (master1) and have
>> HBase running on the HDFS.  Now I am setting up the second master
>>  (master2) in order to form HA.  When I used JPS to check the cluster, I
>> found :
>>
>> 2782 Jps
>> 2126 NameNode
>> 2720 SecondaryNameNode
>> i.e. The datanode on this server could not be started
>>
>> In the log file, found:
>> 2012-11-16 10:28:44,851 ERROR
>> org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException:
>> Incompatible namespaceIDs in /app/hadoop/tmp/dfs/data: namenode namespaceID
>> = 1356148070; datanode namespaceID = 1151604993
>>
>>
>>
>> One of the possible solutions to fix this issue is to:  stop the cluster,
>> reformat the NameNode, restart the cluster.
>> QUESTION: As I already have HBASE running on the cluster, if I reformat
>> the NameNode, do I need to reinstall the entire HBASE? I don't mind to have
>> all data lost as I don't have many data in HBASE and HDFS, however I don't
>> want to re-install HBASE again.
>>
>>
>> On the other hand, I have tried another solution: stop the DataNode, edit
>> the namespaceID in current/VERSION (i.e. set namespaceID=1151604993),
>> restart the datanode, it doesn't work:
>> Warning: $HADOOP_HOME is deprecated.
>> starting master2, logging to
>> /usr/local/hadoop-1.0.4/libexec/../logs/hadoop-hduser-master2-master2.out
>> Exception in thread "main" java.lang.NoClassDefFoundError: master2
>> Caused by: java.lang.ClassNotFoundException: master2
>> at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
>> at java.security.AccessController.doPrivileged(Native Method)
>>  at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
>> at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
>>  at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
>> at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
>> Could not find the main class: master2.  Program will exit.
>> QUESTION: Any other solutions?
>>
>>
>>
>> Thanks
>>
>>
>>
>>
>>
>>
>>
>
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shashwat shriparv 2012-11-16, 07:53