Invalide mapred.hosts data caused "Tasktracker disallowed by JobTracker" error

[Shi Da Li <li...@cn.ibm.com>]

I am trying to set a multiple-nodes cluster which run hadoop and want to
just permit some nodes to be taskTracker to JobTracker, so I modified
mapred-site.xml and add below lines:

<property>
    <name>mapred.hosts</name>
    <value>/hadoop/mapred/hostallowed</value>
</property>

And add below value in hostallowed file(they can be pinged successfully on
JobTracker):

hc003
hc004
hc004
hc043
hc044
hc045

But after I run the job, it will reported that:
2010-03-30 04:38:55,192 INFO org.apache.hadoop.mapred.TaskTracker:
Tasktracker disallowed by JobTracker.

So who have met such problem and tell me the reason? An example would be
more appreciated. Thanks!

StarLee

Re: Invalide mapred.hosts data caused "Tasktracker disallowed by JobTracker" error

[Allen Wittenauer <aw...@linkedin.com>]

Mapred.hosts and dfs.hosts/exclude are kind of brain dead.  It needs to
match what the hosts represent themselves as.  For example, if hc003
presents itself as hc003.cn.ibm.com, you need to put the FQDN in the hosts
file.


On 3/29/10 4:12 PM, "Shi Da Li" <li...@cn.ibm.com> wrote:

> 
> I am trying to set a multiple-nodes cluster which run hadoop and want to
> just permit some nodes to be taskTracker to JobTracker, so I modified
> mapred-site.xml and add below lines:
> 
> <property>
>     <name>mapred.hosts</name>
>     <value>/hadoop/mapred/hostallowed</value>
> </property>
> 
> And add below value in hostallowed file(they can be pinged successfully on
> JobTracker):
> 
> hc003
> hc004
> hc004
> hc043
> hc044
> hc045
> 
> But after I run the job, it will reported that:
> 2010-03-30 04:38:55,192 INFO org.apache.hadoop.mapred.TaskTracker:
> Tasktracker disallowed by JobTracker.
> 
> So who have met such problem and tell me the reason? An example would be
> more appreciated. Thanks!
> 
> StarLee