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Date: Thu, 5 Nov 2009 11:34:28 -0800
Message-ID: <a06de5520911051134r7420e8dbqfac901283eaf931a@mail.gmail.com>
Subject: Re: API for node entry to the cluster.
From: Avinash Lakshman <avinash.lakshman@gmail.com>
To: zookeeper-user@hadoop.apache.org
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Ah. Sorry. But I got it. I guess what Henry is working on is what I am
looking for.

Thanks
A

On Thu, Nov 5, 2009 at 11:32 AM, Ted Dunning <ted.dunning@gmail.com> wrote:

> You have two options.
>
> What Henry is talking about is a sophisticated update to ZK internals that
> does a very nice job of handling all the possible split-brain issues and
> other pathologies that can result from growing or shrinking a cluster.  His
> patch isn't ready yet, but when it is, it should be really nice.
>
> What I am talking about is pretty tame hack that allows you to get 99% of
> the result needed with very little effort.  It can be done today.
>
> Restarting servers one at a time is conventionally used for minor releases
> of ZK and can be (ab)used to allow configuration changes.
>
> I don't quite follow what you are saying in your second and third sentences
> so I can't answer the question in your fourth.
>
> Can you clarify what you mean?  I halfway suspect you dropped a word
> somewhere.
>
> On Thu, Nov 5, 2009 at 11:24 AM, Avinash Lakshman <
> avinash.lakshman@gmail.com> wrote:
>
> > I would prefer not restarting. Start/Stop the new/old process and then
> > start
> > a round of consensus for adding/removing a machine. I guess if one can do
> > that then there is stopping of process required.  Am I missing something
> > here?
> >
> > A
> >
> > On Thu, Nov 5, 2009 at 11:14 AM, Ted Dunning <ted.dunning@gmail.com>
> > wrote:
> >
> > > It is pretty easy to do by hand and is pretty easy to script (it was
> for
> > > us).
> > >
> > > The process for adding is
> > >
> > > a) configure and start a new node
> > >
> > > b) re-configure and restart each existing node in turn to know about
> the
> > > new
> > > node
> > >
> > > you now have a larger cluster.
> > >
> > > To drop a node,
> > >
> > > a) reconfigure and restart each surviving node
> > >
> > > b) kill the node(s) that is(are) leaving
> > >
> > > you now have a smaller cluster.
> > >
> > > On Thu, Nov 5, 2009 at 11:02 AM, Avinash Lakshman <
> > > avinash.lakshman@gmail.com> wrote:
> > >
> > > > Hi All
> > > >
> > > > Is it possible to remove nodes and add nodes dynamically to the ZK
> > > cluster
> > > > via API? Any plans in the future to do this?
> > > >
> > > > TIA
> > > > A
> > > >
> > >
> > >
> > >
> > > --
> > > Ted Dunning, CTO
> > > DeepDyve
> > >
> >
>
>
>
> --
> Ted Dunning, CTO
> DeepDyve
>

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