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Posted to mapreduce-user@hadoop.apache.org by "MrAsanjar ." <af...@gmail.com> on 2015/05/08 18:50:54 UTC
namenode uestion
hi all,
I have an hdfs question, my understanding is, namenode sends a list of
datanodes to hadoop client to send data blocks based on replication
setting. The question is, does the list from namenode has IP addresses or
hostnames, or both of the datanodes.
NN -------> Client ----> DN1 ------> DN2 ------> DN3
Re: namenode uestion
Posted by Harsh J <ha...@cloudera.com>.
Unless you turn on "dfs.client.use.datanode.hostname", the NN will
always use IPs to denote replica location addresses.
On Sun, May 10, 2015 at 9:41 PM, Pravin Sinha <pk...@yahoo.com> wrote:
> Hi Asanjar,
>
> My understanding is that it returns serialized BlockLocation instances which
> holds the location information for an HDFS block. It contains hostnames and
> hostnames:ports of datanodes apart from some other info.
>
> I am a newbie in Hadoop, somebody may connfirm on this.
>
> Regards,
> Pravin
>
>
>
> On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
>
>
> hi all,
> I have an hdfs question, my understanding is, namenode sends a list of
> datanodes to hadoop client to send data blocks based on replication setting.
> The question is, does the list from namenode has IP addresses or hostnames,
> or both of the datanodes.
>
> NN -------> Client ----> DN1 ------> DN2 ------> DN3
>
>
--
Harsh J
Re: namenode uestion
Posted by Harsh J <ha...@cloudera.com>.
Unless you turn on "dfs.client.use.datanode.hostname", the NN will
always use IPs to denote replica location addresses.
On Sun, May 10, 2015 at 9:41 PM, Pravin Sinha <pk...@yahoo.com> wrote:
> Hi Asanjar,
>
> My understanding is that it returns serialized BlockLocation instances which
> holds the location information for an HDFS block. It contains hostnames and
> hostnames:ports of datanodes apart from some other info.
>
> I am a newbie in Hadoop, somebody may connfirm on this.
>
> Regards,
> Pravin
>
>
>
> On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
>
>
> hi all,
> I have an hdfs question, my understanding is, namenode sends a list of
> datanodes to hadoop client to send data blocks based on replication setting.
> The question is, does the list from namenode has IP addresses or hostnames,
> or both of the datanodes.
>
> NN -------> Client ----> DN1 ------> DN2 ------> DN3
>
>
--
Harsh J
Re: namenode uestion
Posted by Harsh J <ha...@cloudera.com>.
Unless you turn on "dfs.client.use.datanode.hostname", the NN will
always use IPs to denote replica location addresses.
On Sun, May 10, 2015 at 9:41 PM, Pravin Sinha <pk...@yahoo.com> wrote:
> Hi Asanjar,
>
> My understanding is that it returns serialized BlockLocation instances which
> holds the location information for an HDFS block. It contains hostnames and
> hostnames:ports of datanodes apart from some other info.
>
> I am a newbie in Hadoop, somebody may connfirm on this.
>
> Regards,
> Pravin
>
>
>
> On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
>
>
> hi all,
> I have an hdfs question, my understanding is, namenode sends a list of
> datanodes to hadoop client to send data blocks based on replication setting.
> The question is, does the list from namenode has IP addresses or hostnames,
> or both of the datanodes.
>
> NN -------> Client ----> DN1 ------> DN2 ------> DN3
>
>
--
Harsh J
Re: namenode uestion
Posted by Harsh J <ha...@cloudera.com>.
Unless you turn on "dfs.client.use.datanode.hostname", the NN will
always use IPs to denote replica location addresses.
On Sun, May 10, 2015 at 9:41 PM, Pravin Sinha <pk...@yahoo.com> wrote:
> Hi Asanjar,
>
> My understanding is that it returns serialized BlockLocation instances which
> holds the location information for an HDFS block. It contains hostnames and
> hostnames:ports of datanodes apart from some other info.
>
> I am a newbie in Hadoop, somebody may connfirm on this.
>
> Regards,
> Pravin
>
>
>
> On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
>
>
> hi all,
> I have an hdfs question, my understanding is, namenode sends a list of
> datanodes to hadoop client to send data blocks based on replication setting.
> The question is, does the list from namenode has IP addresses or hostnames,
> or both of the datanodes.
>
> NN -------> Client ----> DN1 ------> DN2 ------> DN3
>
>
--
Harsh J
Re: namenode uestion
Posted by Pravin Sinha <pk...@yahoo.com>.
Hi Asanjar,
My understanding is that it returns serialized BlockLocation instances which holds the location information for an HDFS block. It contains hostnames and hostnames:ports of datanodes apart from some other info.
I am a newbie in Hadoop, somebody may connfirm on this.
Regards,Pravin
On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
hi all,
I have an hdfs question, my understanding is, namenode sends a list of datanodes to hadoop client to send data blocks based on replication setting. The question is, does the list from namenode has IP addresses or hostnames, or both of the datanodes.
NN -------> Client ----> DN1 ------> DN2 ------> DN3
Re: namenode uestion
Posted by Pravin Sinha <pk...@yahoo.com>.
Hi Asanjar,
My understanding is that it returns serialized BlockLocation instances which holds the location information for an HDFS block. It contains hostnames and hostnames:ports of datanodes apart from some other info.
I am a newbie in Hadoop, somebody may connfirm on this.
Regards,Pravin
On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
hi all,
I have an hdfs question, my understanding is, namenode sends a list of datanodes to hadoop client to send data blocks based on replication setting. The question is, does the list from namenode has IP addresses or hostnames, or both of the datanodes.
NN -------> Client ----> DN1 ------> DN2 ------> DN3
Re: namenode uestion
Posted by Pravin Sinha <pk...@yahoo.com>.
Hi Asanjar,
My understanding is that it returns serialized BlockLocation instances which holds the location information for an HDFS block. It contains hostnames and hostnames:ports of datanodes apart from some other info.
I am a newbie in Hadoop, somebody may connfirm on this.
Regards,Pravin
On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
hi all,
I have an hdfs question, my understanding is, namenode sends a list of datanodes to hadoop client to send data blocks based on replication setting. The question is, does the list from namenode has IP addresses or hostnames, or both of the datanodes.
NN -------> Client ----> DN1 ------> DN2 ------> DN3
Re: namenode uestion
Posted by Pravin Sinha <pk...@yahoo.com>.
Hi Asanjar,
My understanding is that it returns serialized BlockLocation instances which holds the location information for an HDFS block. It contains hostnames and hostnames:ports of datanodes apart from some other info.
I am a newbie in Hadoop, somebody may connfirm on this.
Regards,Pravin
On Friday, 8 May 2015 10:21 PM, MrAsanjar . <af...@gmail.com> wrote:
hi all,
I have an hdfs question, my understanding is, namenode sends a list of datanodes to hadoop client to send data blocks based on replication setting. The question is, does the list from namenode has IP addresses or hostnames, or both of the datanodes.
NN -------> Client ----> DN1 ------> DN2 ------> DN3