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Posted to user@zookeeper.apache.org by Bill Hastings <bl...@gmail.com> on 2015/07/07 10:34:10 UTC
3 node ZK cluster
I have a 3 node ZK cluster. I bring down 2 nodes. Should I be able to
connect to the cluster via zkCli? I am assuming the cluster would be
available for reads but my zkCli just bails out. Why?
--
Cheers
Bill
RE: 3 node ZK cluster
Posted by Rakesh R <ra...@huawei.com>.
Hi Bill,
Could you take a look at the "read-only" server mode.
Following are some of the development thoughts from wiki. I hope this will give some more information.
http://wiki.apache.org/hadoop/ZooKeeper/GSoCReadOnlyMode
Probably you can try connecting the zookeeper shell using -r option, this is for 'can be read only' client.
bin/zkCli.sh -server machineIP:clientPort -r
-Rakesh
-----Original Message-----
From: Bill Hastings [mailto:bllhastings@gmail.com]
Sent: 07 July 2015 14:11
To: user@zookeeper.apache.org
Subject: Re: 3 node ZK cluster
So how can a client handle this situation?
On Tue, Jul 7, 2015 at 1:37 AM, Ivan Kelly <iv...@apache.org> wrote:
> Connecting involves creating a session, which involves a write to the
> state, so it cannot happen if a majority of nodes is down.
>
> -Ivan
>
> On Tue, Jul 7, 2015 at 10:34 AM Bill Hastings <bl...@gmail.com>
> wrote:
>
> > I have a 3 node ZK cluster. I bring down 2 nodes. Should I be able
> > to connect to the cluster via zkCli? I am assuming the cluster would
> > be available for reads but my zkCli just bails out. Why?
> >
> > --
> > Cheers
> > Bill
> >
>
--
Cheers
Bill
Re: 3 node ZK cluster
Posted by Bill Hastings <bl...@gmail.com>.
So how can a client handle this situation?
On Tue, Jul 7, 2015 at 1:37 AM, Ivan Kelly <iv...@apache.org> wrote:
> Connecting involves creating a session, which involves a write to the
> state, so it cannot happen if a majority of nodes is down.
>
> -Ivan
>
> On Tue, Jul 7, 2015 at 10:34 AM Bill Hastings <bl...@gmail.com>
> wrote:
>
> > I have a 3 node ZK cluster. I bring down 2 nodes. Should I be able to
> > connect to the cluster via zkCli? I am assuming the cluster would be
> > available for reads but my zkCli just bails out. Why?
> >
> > --
> > Cheers
> > Bill
> >
>
--
Cheers
Bill
Re: 3 node ZK cluster
Posted by Ivan Kelly <iv...@apache.org>.
Connecting involves creating a session, which involves a write to the
state, so it cannot happen if a majority of nodes is down.
-Ivan
On Tue, Jul 7, 2015 at 10:34 AM Bill Hastings <bl...@gmail.com> wrote:
> I have a 3 node ZK cluster. I bring down 2 nodes. Should I be able to
> connect to the cluster via zkCli? I am assuming the cluster would be
> available for reads but my zkCli just bails out. Why?
>
> --
> Cheers
> Bill
>
Re: 3 node ZK cluster
Posted by Flavio P JUNQUEIRA <fp...@apache.org>.
You may want to have a look at the read only server mode feature:
http://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html
-Flavio
On Tue, Jul 7, 2015 at 9:34 AM, Bill Hastings <bl...@gmail.com> wrote:
> I have a 3 node ZK cluster. I bring down 2 nodes. Should I be able to
> connect to the cluster via zkCli? I am assuming the cluster would be
> available for reads but my zkCli just bails out. Why?
>
> --
> Cheers
> Bill
>