Hi Yuvraj,
Yes. The starting point for the Hadoop file API is the
'FileSystem' class. Hadoop’s FileSystem provides the us with
FSDataInputStream and FSDataInputStream classes for reading and
writing files.
Regards,
Mohammad Tariq
On Thu, Jul 19, 2012 at 3:31 PM, Yuvrajsinh Chauhan
<yuvraj.chau...@elitecore.com> wrote:
> So, I understand that, If I want to write a file then I need to change the
> code of my external application need to integrate Hadoop read-write
> command/API.
>
>
>
> Regards,
>
> Yuvrajsinh Chauhan
>
>
>
> From: Saniya Khalsa [mailto:saniya.kha...@gmail.com]
> Sent: 19 July 2012 15:27
> To: hdfs-user@hadoop.apache.org; bejoy.had...@gmail.com
>
>
> Subject: Re: Hadoop filesystem directories not visible
>
>
>
> Thanks Bejoy!!
>
>
> On Thu, Jul 19, 2012 at 3:22 PM, Bejoy KS <bejoy.had...@gmail.com> wrote:
>
> Hi Saniya
>
> In hdfs the directory exists only as meta data in the name node. There is no
> real hierarchical existence like normal file system. It is the data in the
> files that is stored as hdfs blocks distributed across data nodes. You see
> these hdfs blocks arranged in dfs.data.dir .
>
> Regards
> Bejoy KS
>
> Sent from handheld, please excuse typos.
>
> ________________________________
>
> From: "Yuvrajsinh Chauhan" <yuvraj.chau...@elitecore.com>
>
> Date: Thu, 19 Jul 2012 15:16:24 +0530
>
> To: <hdfs-user@hadoop.apache.org>
>
> ReplyTo: hdfs-user@hadoop.apache.org
>
> Subject: RE: Hadoop filesystem directories not visible
>
>
>
> Dear Saniya,
>
>
>
> I Second to you on this. Am also find exactly the same folder on secondary
> data node.
>
> Also, How can I write files from my external application ?
>
>
>
> Regards,
>
>
>
> Yuvrajsinh Chauhan || Sr. DBA || CRESTEL-PSG
>
> Elitecore Technologies Pvt. Ltd.
>
> 904, Silicon Tower || Off C.G.Road
>
> Behind Pariseema Building || Ahmedabad || INDIA
>
> [GSM]: +91 9727746022
>
>
>
> From: Saniya Khalsa [mailto:saniya.kha...@gmail.com]
> Sent: 19 July 2012 14:58
> To: hdfs-user@hadoop.apache.org
> Subject: Re: Hadoop filesystem directories not visible
>
>
>
> Hi Mohammad Tariq,
>
>
>
> Thanks for the reply!!
>
> The path to dfs.data.dir is /app/hadoop/tmp/dfs/data
>
> when i go there i find only these :
>
> BlocksBeingWriiten
> Current
> Detach
> In_use.lock
> storage
> tmp
>
> I am unable to see the created directories here.
>
> Regards
> Saniya
>
> On Thu, Jul 19, 2012 at 2:39 PM, Mohammad Tariq <donta...@gmail.com> wrote:
>
> Hello Saniya,
>
> If you are talking about the local FS, then it will be present
> at the location specified as the value of 'dfs.data.dir' property in
> hdfs-site.xml file.
>
> Regards,
> Mohammad Tariq
>
>
>
> On Thu, Jul 19, 2012 at 1:09 PM, Saniya Khalsa <saniya.kha...@gmail.com>
> wrote:
>> Hi,
>>
>> I ran these commands
>>
>> $HADOOP_HOME/bin/hadoop fs -mkdir /tmp
>> $HADOOP_HOME/bin/hadoop fs -mkdir /user
>> The directories got created and I can now see the directories using
>> following commands:
>>
>> [hadoop@master bin]$ ./hadoop fs -ls /
>> Found 5 items
>> drwxr-xr-x - hadoop supergroup 0 2012-07-16 14:11 /app
>> drwxr-xr-x - hadoop supergroup 0 2012-07-17 17:41 /hadoop
>> drwxr-xr-x - hadoop supergroup 0 2012-07-18 14:11 /hbase
>> drwxr-xr-x - hadoop supergroup 0 2012-07-19 14:11 /tmp
>> drwxr-xr-x - hadoop supergroup 0 2012-07-19 17:41 /user
>>
>>
>> I can see this data from both the nodes by typing the command ,but i
>> cannot
>> view the directories created in the file path anywhere.Please tell me how
>> to see these directories created in file system.
>>
>> Thanks
>
>
>
>
