Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Zookeeper, mail # user - Growing a cluster


Copy link to this message
-
Re: Growing a cluster
Jared Cantwell 2011-05-05, 16:11
Great information guys-- this helps me understand what needs done when
expanding from 2 nodes to X nodes.

Does anyone have insight on going from 1 node to 3 nodes?

~Jared

2011/5/5 Chang Song <[EMAIL PROTECTED]>

>
> We are in a bit similar situation.
>
> 3 node -> 5 node ensemble.
>
> The only way to do this is the following.
>
> Assumption is that we have one DNS hostname for three zookeeper ensemble
> IP.
> Since five node ensemble allows 2 node failure for quorum, we can do
>
>
> 0. First all two new ensemble IPs
>
> 1. change all three existing node config (zoo.cfg) and add two new node
> information
>    Restart all three existing nodes in a sequence.
>
> 2. Replicate the new existing zoo.cfg to two new ensemble
>    Start Zookeeper on two new server
>
>
> You can do this in backward sequence (0 -> 2 -> 1)
> In your case, you can do 0 -> 2 -> 1, I think.
>
> Chang
>
>
>
> 2011. 5. 5., 오후 9:57, Jared Cantwell 작성:
>
> > It would be acceptable to me to do this non-dynamically and non-rolling
> as
> > well. For example, I can shut down all nodes, make necessary
> modifications
> > to config files, and then restart all nodes.  If I do this, should
> switching
> > from standalone mode to multi-node mode work?  Has anyone done this
> before?
> > Preliminary tests seem to work, but I haven't looked into all the race
> > conditions and such yet.
> >
> > ~Jared
> >
> > On Thu, May 5, 2011 at 12:02 AM, Alexander Shraer <[EMAIL PROTECTED]
> >wrote:
> >
> >> Hi Jared,
> >>
> >> Currently there is no support for adding and removing zookeeper nodes
> >> dynamically. See:
> >> https://issues.apache.org/jira/browse/ZOOKEEPER-107
> >>
> >> We're currently working to add this feature. However, AFAIK there is no
> >> intention to support
> >> transformation between standalone and multi-node modes, only membership
> >> changes in multi-node mode.
> >>
> >> Regards,
> >> Alex
> >>
> >>
> >>> -----Original Message-----
> >>> From: Jared Cantwell [mailto:[EMAIL PROTECTED]]
> >>> Sent: Wednesday, May 04, 2011 7:17 PM
> >>> To: [EMAIL PROTECTED]
> >>> Subject: Growing a cluster
> >>>
> >>> Hello,
> >>>
> >>> Say I was going to grow a cluster from 1 node to 3 nodes.  Is this
> >>> possible,
> >>> and what would be the recommended way?
> >>>
> >>> At first I was thinking that I could go from 1 to 2 and then 2 to 3,
> >>> and it
> >>> seems to be working actually.  But I'm not sure if this is supported,
> >>> mostly
> >>> because in standalone mode the on-disk files are different than they
> >>> are in
> >>> a multi-node configurations.  Mutli-node configurations embed the
> >>> quorum
> >>> incarnation into the filename, which standalone does not.  Should a
> >>> quorum
> >>> node be able to startup using snapshots and logs that a standalone node
> >>> wrote out?  Is there a way around this?
> >>>
> >>> Thanks,
> >>> Jared
> >>
>
>