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MapReduce, mail # user - error while running reduce


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Arindam Choudhury 2013-03-07, 12:31
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Re: error while running reduce
Arindam Choudhury 2013-03-08, 12:10
how can I fix this?
when I run the same job with 1GB of input with 1 map and 1 reducer, it
works fine.
On Thu, Mar 7, 2013 at 11:14 PM, Jagmohan Chauhan <
[EMAIL PROTECTED]> wrote:

> Hi
>
> I think the problem is in replication factor.. As, you are using
> replication factor of 1 and you have a single node the data cannot be
> replicated anywhere else.
>
> On Thu, Mar 7, 2013 at 4:31 AM, Arindam Choudhury <
> [EMAIL PROTECTED]> wrote:
>
>> Hi,
>>
>> I am trying to do a performance analysis of hadoop on virtual machine.
>> When I try to run terasort with 2GB of input data with 1 map and 1 reduce,
>> the map finishes properly, but reduce gives error. I can not understand
>> why? any help?
>>
>> I have a single node hadoop deployment in a virtual machine. The F18
>> virtual machine have 1 core and 2 GB of memory.
>>
>> my configuration:
>> core-site.xml
>> <configuration>
>> <property>
>>   <name>fs.default.name</name>
>>   <value>hdfs://hadoopa.arindam.com:54310</value>
>> </property>
>> <property>
>>   <name>hadoop.tmp.dir</name>
>>   <value>/tmp/${user.name}</value>
>> </property>
>> <property>
>>   <name>fs.inmemory.size.mb</name>
>>   <value>20</value>
>> </property>
>> <property>
>>   <name>io.file.buffer.size</name>
>>   <value>131072</value>
>> </property>
>> </configuration>
>>
>> hdfs-site.xml
>> <configuration>
>> <property>
>>   <name>dfs.name.dir</name>
>>   <value>/home/hadoop/hadoop-dir/name-dir</value>
>> </property>
>> <property>
>>   <name>dfs.data.dir</name>
>>   <value>/home/hadoop/hadoop-dir/data-dir</value>
>> </property>
>> <property>
>>   <name>dfs.block.size</name>
>>   <value>2048000000</value>
>>   <final>true</final>
>> </property>
>> <property>
>>   <name>dfs.replication</name>
>>   <value>1</value>
>> </property>
>> </configuration>
>>
>>
>> mapred-site.xml
>> <configuration>
>> <property>
>>   <name>mapred.job.tracker</name>
>>   <value>hadoopa.arindam.com:54311</value>
>> </property>
>> <property>
>>   <name>mapred.system.dir</name>
>>   <value>/home/hadoop/hadoop-dir/system-dir</value>
>> </property>
>> <property>
>>   <name>mapred.local.dir</name>
>>   <value>/home/hadoop/hadoop-dir/local-dir</value>
>> </property>
>> <property>
>>   <name>mapred.map.child.java.opts</name>
>>   <value>-Xmx1024M</value>
>> </property>
>> <property>
>>   <name>mapred.reduce.child.java.opts</name>
>>   <value>-Xmx1024M</value>
>> </property>
>> </configuration>
>>
>> I created 2GB of data to run tera sort.
>>
>> hadoop dfsadmin -report
>> Configured Capacity: 21606146048 (20.12 GB)
>> Present Capacity: 14480427242 (13.49 GB)
>> DFS Remaining: 12416368640 (11.56 GB)
>> DFS Used: 2064058602 (1.92 GB)
>> DFS Used%: 14.25%
>> Under replicated blocks: 0
>> Blocks with corrupt replicas: 0
>> Missing blocks: 0
>>
>> -------------------------------------------------
>> Datanodes available: 1 (1 total, 0 dead)
>>
>> Name: 192.168.122.32:50010
>> Decommission Status : Normal
>> Configured Capacity: 21606146048 (20.12 GB)
>> DFS Used: 2064058602 (1.92 GB)
>> Non DFS Used: 7125718806 (6.64 GB)
>> DFS Remaining: 12416368640(11.56 GB)
>> DFS Used%: 9.55%
>> DFS Remaining%: 57.47%
>>
>>
>> But when I run the terasort, i am getting the following error:
>>
>> 13/03/04 17:56:16 INFO mapred.JobClient: Task Id :
>> attempt_201303041741_0002_r_000000_0, Status : FAILED
>> org.apache.hadoop.ipc.RemoteException: java.io.IOException: File
>> /user/hadoop/output/_temporary/_attempt_201303041741_0002_r_000000_0/part-00000
>> could only be replicated to 0 nodes, instead of 1
>>
>> hadoop dfsadmin -report
>> Configured Capacity: 21606146048 (20.12 GB)
>> Present Capacity: 10582014209 (9.86 GB)
>> DFS Remaining: 8517738496 (7.93 GB)
>> DFS Used: 2064275713 (1.92 GB)
>> DFS Used%: 19.51%
>> Under replicated blocks: 2
>> Blocks with corrupt replicas: 0
>> Missing blocks: 0
>>
>> -------------------------------------------------
>> Datanodes available: 1 (1 total, 0 dead)
>>
>> Name: 192.168.122.32:50010
>> Decommission Status : Normal