Thanks Ted.

>> knowing the host list of master role in Slider script or template is not
supported by either Slider or YARN.
[Yong] If there is only one instance of master role, at least I could know
its host name by COMPONENT_HOST in slave hosts, right? If so, I could work
it around to just configure one master.

Yong

On Tue, Dec 30, 2014 at 10:59 PM, Ted Yu <[email protected]> wrote:

> What's the timeframe for this migration ?
>
> If time permits, you should consider rewriting master failover logic in
> your application.
> Using zookeeper is a common technique. HBase, e.g., registers active master
> under a well known zookeeper znode.
>
> This is much more flexible than the way you described.
>
> Again, knowing the host list of master role in Slider script or template is
> not supported by either Slider or YARN.
>
> Cheers
>
> On Tue, Dec 30, 2014 at 7:50 PM, Yong Feng <[email protected]> wrote:
>
> > ah, rs_hosts means all the nodes managed by YARN.
> >
> > I know a little about labels feature of YARN which adds a tag to host and
> > allow yarn API client to filter hosts according to the tag. I don't think
> > it helps my case.
> >
> > Taking a typical master/slave cluster as an example. To support
> > active-passive fail over, we need define multiple instances for master
> role
> > (unfortunately it does not use Zookeeper as the cluster is implemented
> 10+
> > years ago before Zookeeper).  In slave node, a list of mast host are
> > specified in conf file, so that slave node could contact master.
> >
> > To deploy such cluster, we need know host list of master and configure
> them
> > in the conf file of slave. Changing membership of master need restart
> whole
> > cluster so we will not support flex up/down role of master.
> >
> > How can I know the host list of master role in Slider script or template?
> >
> > Thanks,
> >
> > Yong
> >
> > On Tue, Dec 30, 2014 at 9:08 PM, Ted Yu <[email protected]> wrote:
> >
> > > bq. host list of all the instances of a component
> > >
> > > Are you using node labels feature of YARN ?
> > > If not, the list would comprise of all the nodes in your YARN cluster.
> > >
> > > Cheers
> > >
> > > On Tue, Dec 30, 2014 at 4:43 PM, Yong Feng <[email protected]>
> > wrote:
> > >
> > > > Hi Team,
> > > >
> > > > The template of regionserver of HBase application uses following
> > scripts
> > > to
> > > > configure configuraiton file of regionserver of HBase. I did not find
> > > where
> > > > the rs_hosts is defined in any file in Slider HBase package. How a
> > > template
> > > > is designed is mentioned a little at the end of
> > > >
> > > >
> > >
> >
> http://slider.incubator.apache.org/docs/slider_specs/application_package.html
> > > > ,
> > > > but cannot help much.
> > > >
> > > > {% for host in rs_hosts %}{{host}}
> > > > {% endfor %}
> > > >
> > > > Does anyone know where rs_hosts is defined? I am now writing a
> package
> > > for
> > > > a HPC applicaiton and need to know host list of all the instances of
> a
> > > > component to prepare configuration file of the application.
> > > >
> > > > Thanks,
> > > >
> > > > Yong
> > > >
> > >
> >
>

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