Hi Guys,

How to find Blacklisted Nodes via, command line. I want to see job
Tracker Blacklisted Nodes and hdfs Blacklisted Nodes.

and also how to clear blacklisted nodes to clear start. The only option to
restart the service. some other way clear the Blacklisted Nodes.

please guide me.

-Dhanasekaran.

Did I learn something today? If not, I wasted it.

*bin/hadoop dfsadmin -report should give you what you are looking for.*
*
*
*a node is blacklisted only if there are too many failures on a particular
node. You can clear it by restarting the particular datanode or tasktracker
service. This is for the better performance of your hadoop cluster to
remove a node where too many failures are happening so that you can figure
out the reason and then add it back in cluster. you can also exclude the
node from the cluster all together. *
*
*
*I never tried myself removing a node from blacklist on the fly so not sure
how that is done. I will wait if someone can tell me witout restart its
possible or not (without increasing the failure thresholds ) *
On Wed, Jan 30, 2013 at 9:35 PM, Dhanasekaran Anbalagan
<[EMAIL PROTECTED]>wrote:

> Hi Guys,
>
> How to find Blacklisted Nodes via, command line. I want to see job
> Tracker Blacklisted Nodes and hdfs Blacklisted Nodes.
>
> and also how to clear blacklisted nodes to clear start. The only option to
> restart the service. some other way clear the Blacklisted Nodes.
>
> please guide me.
>
> -Dhanasekaran.
>
> Did I learn something today? If not, I wasted it.
>

--
Nitin Pawar

Hi,

Part answer: you can get the blacklisted tasktrackers using the command
line:

mapred job -list-blacklisted-trackers.

Also, I think that a blacklisted tasktracker becomes 'unblacklisted' if it
works fine after some time. Though I am not very sure about this.

Thanks
hemanth
On Wed, Jan 30, 2013 at 9:35 PM, Dhanasekaran Anbalagan
<[EMAIL PROTECTED]>wrote:

> Hi Guys,
>
> How to find Blacklisted Nodes via, command line. I want to see job
> Tracker Blacklisted Nodes and hdfs Blacklisted Nodes.
>
> and also how to clear blacklisted nodes to clear start. The only option to
> restart the service. some other way clear the Blacklisted Nodes.
>
> please guide me.
>
> -Dhanasekaran.
>
> Did I learn something today? If not, I wasted it.
>