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From li ping <li.j...@gmail.com>
Subject Re: Help: 1) Hadoop processes still are running after we stopped > hadoop.2) How to exclude a dead node?
Date Wed, 08 Dec 2010 06:17:40 GMT
I am not sure I have fully understand your post.
You mean the conf/slaves only be used for stop/start script to start or stop
the datanode/tasktracker?
And the conf/master only contains the information about the secondary
namenode?

Thanks

On Wed, Dec 8, 2010 at 1:44 PM, Sudhir Vallamkondu <
Sudhir.Vallamkondu@icrossing.com> wrote:

> There is a proper decommissioning process to remove dead nodes. See the FAQ
> link here:
>
> http://wiki.apache.org/hadoop/FAQ#I_want_to_make_a_large_cluster_smaller_by_
> taking_out_a_bunch_of_nodes_simultaneously._How_can_this_be_done.3F
>
> For a fact $HADOOP_HOME/conf/slaves is not used by the name node to keep
> track of datanodes/tasktracker. It is merely used by the stop/start hadoop
> scripts to know which nodes to start datanode / tasktracker services.
> Similarly there is confusion regarding understanding the
> $HADOOP_HOME/conf/master file. That file contains the details of the
> machine
> where secondary name node is running, not the name node/job tracker.
>
> With regards to not all java/hadoop processes getting killed, this may be
> happening due to hadoop loosing track of pid files. By default the pid
> files
> are configured to be created in the /tmp directory. If these pid files get
> deleted then stop/start scripts cannot detect running hadoop processes. I
> suggest changing location of pid files to a persistent location like
> /var/hadoop/. The $HADOOP_HOME/conf/hadoop-env.sh file has details on
> configuring the PID location
>
> - Sudhir
>
>
> On 12/7/10 5:07 PM, "common-user-digest-help@hadoop.apache.org"
> <common-user-digest-help@hadoop.apache.org> wrote:
>
> > From: Tali K <ncherryus@hotmail.com>
> > Date: Tue, 7 Dec 2010 10:40:16 -0800
> > To: <core-user@hadoop.apache.org>
> > Subject: Help: 1) Hadoop processes still are running after we stopped
> > hadoop.2)  How to exclude a dead node?
> >
> >
> > 1)When I stopped hadoop, we checked all the nodes and found that 2 or 3
> > java/hadoop processes were still running on each node.  So we went to
> each
> > node and did a 'killall java' - in some cases I had to do 'killall -9
> java'.
> > My question : why is is this happening and what would be recommendations
> , how
> > to make sure that there is no hadoop processes running after I stopped
> hadoop
> > with stop-all.sh?
> >
> > 2) Also we have a dead node. We  removed this node  from
> > $HADOOP_HOME/conf/slaves.  This file is supposed to tell the namenode
> >  which machines are supposed to be datanodes/tasktrackers.
> > We  started hadoop again, and were surprised to see a dead node in
>  hadoop
> > 'report' ("$HADOOP_HOME/bin/hadoop dfsadmin -report|less")
> > It is only after blocking a deadnode and restarting hadoop, deadnode no
> longer
> > showed up in hreport.
> > Any recommendations, how to deal with dead nodes?
>
>
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-- 
-----李平

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