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Posted to mapreduce-user@hadoop.apache.org by "MrAsanjar ." <af...@gmail.com> on 2014/07/02 23:03:14 UTC
A Datanode shutdown question?
If a datanode is shut-downed by calling "hadoop-daemons.sh stop datanode",
how would the namenode gets notified that a datanode is no longer active?
does datanode send a SHUTDOWN_MSG to the namenode? does namenode has to
wait for heartbeat timeout?
Re: A Datanode shutdown question?
Posted by varun kumar <va...@gmail.com>.
Generally Datanode sends it heartbeat to namenode for every 3 seconds.
If datanode stops sending its heartbeat to name node with in 3
seconds,Namenode thinks it is dead.
On Wed, Jul 2, 2014 at 5:03 PM, MrAsanjar . <af...@gmail.com> wrote:
> If a datanode is shut-downed by calling "hadoop-daemons.sh stop datanode",
> how would the namenode gets notified that a datanode is no longer active?
> does datanode send a SHUTDOWN_MSG to the namenode? does namenode has to
> wait for heartbeat timeout?
>
--
Regards,
Varun Kumar.P
Re: A Datanode shutdown question?
Posted by varun kumar <va...@gmail.com>.
Generally Datanode sends it heartbeat to namenode for every 3 seconds.
If datanode stops sending its heartbeat to name node with in 3
seconds,Namenode thinks it is dead.
On Wed, Jul 2, 2014 at 5:03 PM, MrAsanjar . <af...@gmail.com> wrote:
> If a datanode is shut-downed by calling "hadoop-daemons.sh stop datanode",
> how would the namenode gets notified that a datanode is no longer active?
> does datanode send a SHUTDOWN_MSG to the namenode? does namenode has to
> wait for heartbeat timeout?
>
--
Regards,
Varun Kumar.P
Re: A Datanode shutdown question?
Posted by varun kumar <va...@gmail.com>.
Generally Datanode sends it heartbeat to namenode for every 3 seconds.
If datanode stops sending its heartbeat to name node with in 3
seconds,Namenode thinks it is dead.
On Wed, Jul 2, 2014 at 5:03 PM, MrAsanjar . <af...@gmail.com> wrote:
> If a datanode is shut-downed by calling "hadoop-daemons.sh stop datanode",
> how would the namenode gets notified that a datanode is no longer active?
> does datanode send a SHUTDOWN_MSG to the namenode? does namenode has to
> wait for heartbeat timeout?
>
--
Regards,
Varun Kumar.P
Re: A Datanode shutdown question?
Posted by varun kumar <va...@gmail.com>.
Generally Datanode sends it heartbeat to namenode for every 3 seconds.
If datanode stops sending its heartbeat to name node with in 3
seconds,Namenode thinks it is dead.
On Wed, Jul 2, 2014 at 5:03 PM, MrAsanjar . <af...@gmail.com> wrote:
> If a datanode is shut-downed by calling "hadoop-daemons.sh stop datanode",
> how would the namenode gets notified that a datanode is no longer active?
> does datanode send a SHUTDOWN_MSG to the namenode? does namenode has to
> wait for heartbeat timeout?
>
--
Regards,
Varun Kumar.P