Re: How to add second Zookeeper to same machine?

2015-08-20 Thread Modassar Ather
You might want to look into the following documentation. These documents
have explanation on how to setup Zookeeper ensemble and Zookeeper
administration.

https://cwiki.apache.org/confluence/display/solr/Setting+Up+an+External+ZooKeeper+Ensemble
http://zookeeper.apache.org/doc/r3.4.6/zookeeperAdmin.html

Regards,
Modassar

On Thu, Aug 20, 2015 at 1:19 PM, Merlin Morgenstern 
merlin.morgenst...@gmail.com wrote:

 I am running 2 dedicated servers on which I plan to install Solrcloud with
 2 solr nodes and 3 ZK.

 From Stackoverflow I learned that the best method for autostarting
 zookeeper on ubuntu 14.04 is to install it via apt-get install
 zookeeperd. I have that running now.

 How could I add a second zookeeper to one machine? The config only allows
 one. Or if this is not possible, what would be the recommended way to get 3
 ZK on 2 dedicated running?

 I have followed a tutorial where I have that setup available va bash
 script, but it seems that the ubuntu zookeeper setup is robust as it offers
 zombie processes and a startup script as well.

 Thank you for any help on this.



How to add second Zookeeper to same machine?

2015-08-20 Thread Merlin Morgenstern
I am running 2 dedicated servers on which I plan to install Solrcloud with
2 solr nodes and 3 ZK.

From Stackoverflow I learned that the best method for autostarting
zookeeper on ubuntu 14.04 is to install it via apt-get install
zookeeperd. I have that running now.

How could I add a second zookeeper to one machine? The config only allows
one. Or if this is not possible, what would be the recommended way to get 3
ZK on 2 dedicated running?

I have followed a tutorial where I have that setup available va bash
script, but it seems that the ubuntu zookeeper setup is robust as it offers
zombie processes and a startup script as well.

Thank you for any help on this.


Re: How to add second Zookeeper to same machine?

2015-08-20 Thread Shawn Heisey
On 8/20/2015 1:49 AM, Merlin Morgenstern wrote:
 I am running 2 dedicated servers on which I plan to install Solrcloud with
 2 solr nodes and 3 ZK.
 
 From Stackoverflow I learned that the best method for autostarting
 zookeeper on ubuntu 14.04 is to install it via apt-get install
 zookeeperd. I have that running now.
 
 How could I add a second zookeeper to one machine? The config only allows
 one. Or if this is not possible, what would be the recommended way to get 3
 ZK on 2 dedicated running?
 
 I have followed a tutorial where I have that setup available va bash
 script, but it seems that the ubuntu zookeeper setup is robust as it offers
 zombie processes and a startup script as well.

It is possible to have multiple zookeeper installs on one machine, but
if you do this, your system will not be fault tolerant.

A simple fact of life is that hardware can fail, and it can fail
completely.  If the motherboard in a server develops a fault, the entire
server is probably going to fail.  If the machine with two zookeepers on
it dies, zookeeper quorum will be lost and SolrCloud will go read-only.
 It will not be possible to write to it, even though there is still a
surviving machine.

Redundant zookeeper requires three completely separate machines, so that
if you lose any one of those machines, the cluster still has a majority
present and stays completely operational.  This means that SolrCloud
requires three machines minimum.  The third server can be a much less
capable machine that runs zookeeper only, but it must be there in order
to achieve true fault tolerance.

Thanks,
Shawn