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Hadoop >> mail # user >> Re: what will happen when HDFS restarts but with some dead nodes


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Re: what will happen when HDFS restarts but with some dead nodes
Hi Nan,

When the Namenode will EXIT the safemode, you, you can assume that all
blocks ARE fully replicated. If the Namenode is still IN safemode that
mean that all blocks are NOT fully replicated.

JM

2013/1/29, Nan Zhu <[EMAIL PROTECTED]>:
> So, we can assume that all blocks are fully replicated at the start point of
> HDFS?
>
> Best,
>
> --
> Nan Zhu
> School of Computer Science,
> McGill University
>
>
>
> On Tuesday, 29 January, 2013 at 10:50 PM, Chen He wrote:
>
>> Hi Nan
>>
>> Namenode will stay in safemode before all blocks are replicated. During
>> this time, the jobtracker can not see any tasktrackers. (MRv1).
>>
>> Chen
>>
>> On Tue, Jan 29, 2013 at 9:04 PM, Nan Zhu <[EMAIL PROTECTED]
>> (mailto:[EMAIL PROTECTED])> wrote:
>> > Hi, all
>> >
>> > I'm wondering if HDFS is stopped, and some of the machines of the
>> > cluster are moved,  some of the block replication are definitely lost
>> > for moving machines
>> >
>> > when I restart the system, will the namenode recalculate the data
>> > distribution?
>> >
>> > Best,
>> >
>> > --
>> > Nan Zhu
>> > School of Computer Science,
>> > McGill University
>> >
>> >
>>
>
>
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB