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From Kun Ren <ren.h...@gmail.com>
Subject Re: Start client side daemon
Date Fri, 22 Jul 2016 15:46:18 GMT
Got it, thanks.

On Fri, Jul 22, 2016 at 11:43 AM, Rakesh Radhakrishnan <rakeshr@apache.org>
wrote:

> Sorry, could you please tell me, what do you meant by "located" ?
>
> Like I mentioned earlier, user applications will talk to the HDFS via
> clients. For example, operations like create/open/write/read/delete files
> etc via client.
>
> Thanks,
> Rakesh
>
>
> On Fri, Jul 22, 2016 at 8:38 PM, Kun Ren <ren.hdfs@gmail.com> wrote:
>
>> Thanks for your reply. So The clients can be located at any machine that
>> has the HDFS client library, correct?
>>
>> On Fri, Jul 22, 2016 at 10:50 AM, Rakesh Radhakrishnan <
>> rakeshr@apache.org> wrote:
>>
>>> Hi Kun,
>>>
>>> HDFS won't start any client side object(for example,
>>> DistributedFileSystem). I can say, HDFS Client -> user applications access
>>> the file system using the HDFS client, a library that exports the HDFS file
>>> system interface. Perhaps, you can visit api docs,
>>> https://hadoop.apache.org/docs/r2.6.1/api/org/apache/hadoop/fs/FileSystem.html
>>> .
>>>
>>> Namenode has RPC server that listens to requests from data nodes,
>>> clients. Datanode has RPC Server which will be used for inter data node
>>> communications. I think, its worth reading the following to get more
>>> information.
>>> https://en.wikipedia.org/wiki/Apache_Hadoop
>>>
>>> https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/HdfsDesign.html#The_Communication_Protocols
>>>
>>> Regards,
>>> Rakesh
>>> Intel
>>>
>>> On Fri, Jul 22, 2016 at 7:21 PM, Kun Ren <ren.hdfs@gmail.com> wrote:
>>>
>>>> Hi Genius,
>>>>
>>>> I understand that we use the command to start namenode and datanode.
>>>> But I don't know how HDFS starts client side and creates the Client side
>>>> object(Like DistributedFileSystem), and client side RPC server? Could you
>>>> please point it out how HDFS start the client side dameon?
>>>> If the client side uses the same RPC server with server side, Can I
>>>> understand that the client side has to be located at either Namenode or
>>>> Datanode?
>>>>
>>>> Thanks so much.
>>>> Kun
>>>>
>>>
>>>
>>
>

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