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Zookeeper, mail # user - zookeeper cluster spanning datacenters


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Damu R 2011-09-22, 14:50
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Fournier, Camille F. 2011-09-22, 15:03
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Ted Dunning 2011-09-22, 15:27
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Re: zookeeper cluster spanning datacenters
kishore g 2011-09-22, 16:13
This is an interesting topic, is there a place where we can get various
possible setup, pros and cons of each and what kind of use case works/does
not work.

thanks,
Kishore G

On Thu, Sep 22, 2011 at 8:27 AM, Ted Dunning <[EMAIL PROTECTED]> wrote:

> One additional architecture that has been proposed for people with only 2
> data centers is to put 2+2 machines in the data centers and then put a tie
> breaker in EC2.
>
> On Thu, Sep 22, 2011 at 8:03 AM, Fournier, Camille F. <
> [EMAIL PROTECTED]> wrote:
>
> > We spread our ZKs across 3 data centers and in fact, these data centers
> are
> > split across global regions (2 or 4 in one region, one in a remote
> region).
> > To keep throughput up (and note that the throughput you have to worry
> about
> > is only write throughput), we always ensure that the master is in one of
> the
> > "local" data centers.
> >
> > If you have a very write-heavy and write time sensitive load, this might
> > affect your performance. It won't affect reads at all because reads are
> > serviced from the memory of the zk you connect to. For a mostly
> > read-intensive load, splitting across data centers is unlikely to cause
> you
> > problems.
> >
> > There is one exception: Monitoring. Even across data centers in the same
> > region, we sometimes see zk dashboard unable to properly monitor the
> leader
> > of a heavily-utilized cluster. This is due to the way the 4lw connections
> > are managed, and something I'm trying to fix.
> >
> > If you have the machines to test, I would recommend running zk-smoketest
>  (
> > https://github.com/phunt/zk-smoketest) on the proposed config.
> >
> > C
> >
> > -----Original Message-----
> > From: Damu R [mailto:[EMAIL PROTECTED]]
> > Sent: Thursday, September 22, 2011 10:50 AM
> > To: [EMAIL PROTECTED]
> > Subject: zookeeper cluster spanning datacenters
> >
> > Hi,
> > I would like to know the downsides of having a zookeeper cluster that
> spans
> > multiple datacenters. The requirement is a datacenter failure should not
> > bring down the zookeeper cluster. From my understanding it is not
> possible
> > to have a hot/cold cluster kind of setup possible. So we are thinking of
> > putting zk servers in 3 colos(1+1+1 or 2+2+3). One of the major drawback
> I
> > could think of is the throughput of the system affected by latency. The
> > system does not require high throughput and can accept some latency. How
> > much effect will the latency have on the throughput of the system? What
> are
> > the other downsides of spreading the cluster across datacenters?
> >
> > Regards
> > Damu
> >
>
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Ted Dunning 2011-09-22, 16:15
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Damu R 2011-09-22, 16:46
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Fournier, Camille F. 2011-09-22, 17:26
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Ted Dunning 2011-09-22, 19:01
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Vishal Kher 2011-09-22, 20:45
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Mahadev Konar 2011-09-22, 20:53
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Flavio Junqueira 2011-09-23, 09:12