You are viewing a plain text version of this content. The canonical link for it is here.
Posted to mapreduce-user@hadoop.apache.org by Himawan Mahardianto <ma...@ugm.ac.id> on 2015/05/19 10:38:29 UTC
how namenode decided which datanode are ready for a client
Hi guys, I know that every datanode where sending heartbeat to prove that
their alive but what method are used by namenode to decide which datanode
are available to client if all datanode where available?
Best Regards
Re: how namenode decided which datanode are ready for a client
Posted by Himawan Mahardianto <ma...@ugm.ac.id>.
but on what category datanode are choosen by namenode, if some client want
to write some data(block) on it via HDFS
how namenode distinguish on one datanode and the other if only I just have
one rack, so rack awareness feature are unused
On Tue, May 19, 2015 at 3:56 PM, rajesh damera <d....@gmail.com> wrote:
> Namenode usually checks for the jobs running on the datanodes, of which
> tasktrackers keep a track of and decides if it still busy running a task.
> On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
>
>> Datanode availability is monitored and decided by Namenode. You usually
>> get permissions, based on the type of user you are, to use a certain number
>> of nodes to run your jobs. These limitations are set by administrators at
>> user level
>>
>> Warm regards
>> Rajesh Damera
>> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
>> wrote:
>>
>>> Hi guys, I know that every datanode where sending heartbeat to prove
>>> that their alive but what method are used by namenode to decide which
>>> datanode are available to client if all datanode where available?
>>>
>>> Best Regards
>>>
>>>
>>
Re: how namenode decided which datanode are ready for a client
Posted by Himawan Mahardianto <ma...@ugm.ac.id>.
but on what category datanode are choosen by namenode, if some client want
to write some data(block) on it via HDFS
how namenode distinguish on one datanode and the other if only I just have
one rack, so rack awareness feature are unused
On Tue, May 19, 2015 at 3:56 PM, rajesh damera <d....@gmail.com> wrote:
> Namenode usually checks for the jobs running on the datanodes, of which
> tasktrackers keep a track of and decides if it still busy running a task.
> On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
>
>> Datanode availability is monitored and decided by Namenode. You usually
>> get permissions, based on the type of user you are, to use a certain number
>> of nodes to run your jobs. These limitations are set by administrators at
>> user level
>>
>> Warm regards
>> Rajesh Damera
>> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
>> wrote:
>>
>>> Hi guys, I know that every datanode where sending heartbeat to prove
>>> that their alive but what method are used by namenode to decide which
>>> datanode are available to client if all datanode where available?
>>>
>>> Best Regards
>>>
>>>
>>
Re: how namenode decided which datanode are ready for a client
Posted by Himawan Mahardianto <ma...@ugm.ac.id>.
but on what category datanode are choosen by namenode, if some client want
to write some data(block) on it via HDFS
how namenode distinguish on one datanode and the other if only I just have
one rack, so rack awareness feature are unused
On Tue, May 19, 2015 at 3:56 PM, rajesh damera <d....@gmail.com> wrote:
> Namenode usually checks for the jobs running on the datanodes, of which
> tasktrackers keep a track of and decides if it still busy running a task.
> On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
>
>> Datanode availability is monitored and decided by Namenode. You usually
>> get permissions, based on the type of user you are, to use a certain number
>> of nodes to run your jobs. These limitations are set by administrators at
>> user level
>>
>> Warm regards
>> Rajesh Damera
>> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
>> wrote:
>>
>>> Hi guys, I know that every datanode where sending heartbeat to prove
>>> that their alive but what method are used by namenode to decide which
>>> datanode are available to client if all datanode where available?
>>>
>>> Best Regards
>>>
>>>
>>
Re: how namenode decided which datanode are ready for a client
Posted by Himawan Mahardianto <ma...@ugm.ac.id>.
but on what category datanode are choosen by namenode, if some client want
to write some data(block) on it via HDFS
how namenode distinguish on one datanode and the other if only I just have
one rack, so rack awareness feature are unused
On Tue, May 19, 2015 at 3:56 PM, rajesh damera <d....@gmail.com> wrote:
> Namenode usually checks for the jobs running on the datanodes, of which
> tasktrackers keep a track of and decides if it still busy running a task.
> On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
>
>> Datanode availability is monitored and decided by Namenode. You usually
>> get permissions, based on the type of user you are, to use a certain number
>> of nodes to run your jobs. These limitations are set by administrators at
>> user level
>>
>> Warm regards
>> Rajesh Damera
>> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
>> wrote:
>>
>>> Hi guys, I know that every datanode where sending heartbeat to prove
>>> that their alive but what method are used by namenode to decide which
>>> datanode are available to client if all datanode where available?
>>>
>>> Best Regards
>>>
>>>
>>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Namenode usually checks for the jobs running on the datanodes, of which
tasktrackers keep a track of and decides if it still busy running a task.
On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
> Datanode availability is monitored and decided by Namenode. You usually
> get permissions, based on the type of user you are, to use a certain number
> of nodes to run your jobs. These limitations are set by administrators at
> user level
>
> Warm regards
> Rajesh Damera
> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
> wrote:
>
>> Hi guys, I know that every datanode where sending heartbeat to prove that
>> their alive but what method are used by namenode to decide which datanode
>> are available to client if all datanode where available?
>>
>> Best Regards
>>
>>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Namenode usually checks for the jobs running on the datanodes, of which
tasktrackers keep a track of and decides if it still busy running a task.
On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
> Datanode availability is monitored and decided by Namenode. You usually
> get permissions, based on the type of user you are, to use a certain number
> of nodes to run your jobs. These limitations are set by administrators at
> user level
>
> Warm regards
> Rajesh Damera
> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
> wrote:
>
>> Hi guys, I know that every datanode where sending heartbeat to prove that
>> their alive but what method are used by namenode to decide which datanode
>> are available to client if all datanode where available?
>>
>> Best Regards
>>
>>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Namenode usually checks for the jobs running on the datanodes, of which
tasktrackers keep a track of and decides if it still busy running a task.
On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
> Datanode availability is monitored and decided by Namenode. You usually
> get permissions, based on the type of user you are, to use a certain number
> of nodes to run your jobs. These limitations are set by administrators at
> user level
>
> Warm regards
> Rajesh Damera
> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
> wrote:
>
>> Hi guys, I know that every datanode where sending heartbeat to prove that
>> their alive but what method are used by namenode to decide which datanode
>> are available to client if all datanode where available?
>>
>> Best Regards
>>
>>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Namenode usually checks for the jobs running on the datanodes, of which
tasktrackers keep a track of and decides if it still busy running a task.
On May 19, 2015 14:23, "rajesh damera" <d....@gmail.com> wrote:
> Datanode availability is monitored and decided by Namenode. You usually
> get permissions, based on the type of user you are, to use a certain number
> of nodes to run your jobs. These limitations are set by administrators at
> user level
>
> Warm regards
> Rajesh Damera
> On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id>
> wrote:
>
>> Hi guys, I know that every datanode where sending heartbeat to prove that
>> their alive but what method are used by namenode to decide which datanode
>> are available to client if all datanode where available?
>>
>> Best Regards
>>
>>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Datanode availability is monitored and decided by Namenode. You usually get
permissions, based on the type of user you are, to use a certain number of
nodes to run your jobs. These limitations are set by administrators at user
level
Warm regards
Rajesh Damera
On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id> wrote:
> Hi guys, I know that every datanode where sending heartbeat to prove that
> their alive but what method are used by namenode to decide which datanode
> are available to client if all datanode where available?
>
> Best Regards
>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Datanode availability is monitored and decided by Namenode. You usually get
permissions, based on the type of user you are, to use a certain number of
nodes to run your jobs. These limitations are set by administrators at user
level
Warm regards
Rajesh Damera
On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id> wrote:
> Hi guys, I know that every datanode where sending heartbeat to prove that
> their alive but what method are used by namenode to decide which datanode
> are available to client if all datanode where available?
>
> Best Regards
>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Datanode availability is monitored and decided by Namenode. You usually get
permissions, based on the type of user you are, to use a certain number of
nodes to run your jobs. These limitations are set by administrators at user
level
Warm regards
Rajesh Damera
On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id> wrote:
> Hi guys, I know that every datanode where sending heartbeat to prove that
> their alive but what method are used by namenode to decide which datanode
> are available to client if all datanode where available?
>
> Best Regards
>
>
Re: how namenode decided which datanode are ready for a client
Posted by rajesh damera <d....@gmail.com>.
Datanode availability is monitored and decided by Namenode. You usually get
permissions, based on the type of user you are, to use a certain number of
nodes to run your jobs. These limitations are set by administrators at user
level
Warm regards
Rajesh Damera
On May 19, 2015 14:08, "Himawan Mahardianto" <ma...@ugm.ac.id> wrote:
> Hi guys, I know that every datanode where sending heartbeat to prove that
> their alive but what method are used by namenode to decide which datanode
> are available to client if all datanode where available?
>
> Best Regards
>
>