Mailing-List: contact user-help@zookeeper.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@zookeeper.apache.org
Received-SPF: pass (athena.apache.org: local policy)
From: "Flavio Junqueira" <fpjunqueira@yahoo.com>
To: <user@zookeeper.apache.org>
References: 
 <CAB3mbkT8wGYAJaF=bYH8GJRTJmQ0ERbnnrToeUVzKkiJgRgOuA@mail.gmail.com>
	<017d01ce7984$06c74650$1455d2f0$@yahoo.com>
 <CAB3mbkRZf447TdY2XjnuEvQuvUofJXr-NKiQPhY=L4Fwe2pfTQ@mail.gmail.com>
In-Reply-To: 
 <CAB3mbkRZf447TdY2XjnuEvQuvUofJXr-NKiQPhY=L4Fwe2pfTQ@mail.gmail.com>
Subject: RE: Backup/restore of an emsemble
Date: Fri, 5 Jul 2013 17:33:26 +0100
Message-ID: <019401ce799d$60440560$20cc1020$@yahoo.com>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
Thread-Index: AQFcLC9kaXimnBB0xBt2pKkP3tPuHgHnPMpIAlROFu+aGQWOwA==
Content-Language: en-gb

In your approach, would you "lock" the zookeeper state and read the data
tree using getData/getChildren? If you have concurrent updates, then you may
end up having an inconsistent snapshot. 

-Flavio

-----Original Message-----
From: Sergey Maslyakov [mailto:evolvah@gmail.com] 
Sent: 05 July 2013 17:12
To: user@zookeeper.apache.org
Subject: Re: Backup/restore of an emsemble

Yes, Flavio, I looked at Exhibitor, but I need a pretty granular control
over a cluster of ZK servers. This is why I'm inclined to build something by
hand. So far, a pair of external export and import clients seems like a
promising approach.

Export would connect to the ensemble and dump out the data into a file on
disk. Import would connect, wipe out the namespace, and then reload the data
from the file that was earlier created by the export client.


On Fri, Jul 5, 2013 at 8:31 AM, Flavio Junqueira
<fpjunqueira@yahoo.com>wrote:

> Sergey,
>
> Have you had a look at Exhibitor?
>
> https://github.com/Netflix/exhibitor
>
> -Flavio
>
> -----Original Message-----
> From: Sergey Maslyakov [mailto:evolvah@gmail.com]
> Sent: 05 July 2013 04:39
> To: user@zookeeper.apache.org
> Subject: Backup/restore of an emsemble
>
> A while ago, Jack Ma asked this question:
>
> http://mail-archives.apache.org/mod_mbox/zookeeper-user/201306.mbox/%3
> CCAB%2 
> BcfdyPDpbUh5FyDT%3D9mU%3DFCHEA1AZpkF6X0nN1t4mjwqu2tA%40mail.gmail.com%
> 3E
>
> I wonder if there were any helpful suggestions that did not go into 
> the mailing list.
>
> I am mostly concerned about restoring data in a Zookeeper ensemble.
>
> There is no document at the project web-site that would explain the 
> restore procedure for a distributed deployment. The home-grown 
> solution that involves stopping the whole cluster, wiping out 
> databases on all but one server, restoring the database on one server, 
> and then bring up the cluster and pray that the populated server 
> becomes the leader and populates the cluster. Such solution seems to be
too error-prone.
>
> Does anyone have recommendations on how to make it robust?
>
> Maybe there is a way to force-populate the ensemble remotely?
>
>
> Thanks,
> /Sergey
>
>