Yes, I think so (I have not JobTracker with me to check, though).
It might be a bit old link (
but it says
"The NameNode and the JobTracker obtains the rack id of the slaves in the
cluster by invoking an API
in an administrator configured module. The API resolves the slave's DNS
name (also IP address) to a rack id. What module to use can be configured
using the configuration item topology.node.switch.mapping.impl. The default
implementation of the same runs a script/command configured using
2013/11/29 Siddharth Tiwari <[EMAIL PROTECTED]>
> Hi Team/ Adam
> Thanks for the response
> When you say to have rack awareness script on jobtracker, you mean I must
> have the script in jobtracker machines as well ? I am using jt ha, where I
> am using mr2 binaries for namenode ha and mr1 for jt ha. But do I need to
> put the script in all four machines or jut Nn
> Sent from my iPhone
> On Nov 29, 2013, at 6:58 AM, "Adam Kawa" <[EMAIL PROTECTED]> wrote:
> I have 2 nics on my datanodes, is it possible to used the one dedicated
>> for replication and other for all other comunication i.e with jt and
>> namenodes ?
> Please correct me, I am wrong, but I have never seen a support for that in
> Hadoop. DataNodes uses limited number of threads for balancing (afaik, 5
> maximally + dfs.datanode.balance.bandwidthPerSec), so this way resources
> used for balancing can be limited.
>> Also eventhough I am using rackawareness script and dfsreport shows the
>> racks jobtracker shows all tasktracker in default rack, how to correct that.
> We switched to YARN recently, so it is difficult for me to check it now.
> Do you have rack-awareness script deployed on the JobTracker machine?