[Linux-cluster] Simple data replication in a cluster

[Vallevand, Mark K]

Thanks.  A good idea.  I've considered using csync2 (and similar things).  I use unison for syncing in my current clusters.  But that is done to simplify installation/configuration by the user.  My scripts push the static application data around the cluster when the user is installing.  


Regards.
Mark K Vallevand   Mark.Vallevand at Unisys.com
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-----Original Message-----
From: Pavel Herrmann [mailto:morpheus.ibis at gmail.com] 
Sent: Thursday, April 03, 2014 04:31 PM
To: linux-cluster at redhat.com
Cc: Vallevand, Mark K
Subject: Re: [Linux-cluster] Simple data replication in a cluster

Hi

On Thursday 03 of April 2014 15:58:30 Vallevand, Mark K wrote:
> I'm looking for a simple way to replicate data within a cluster.
> 
> It looks like my resources will be self-configuring and may need to push
> changes they see to all nodes in the cluster.  The idea being that when a
> node crashes, the resource will have its configuration present on the node
> on which it is restarted.  We're talking about a few kb of data, probably
> in one file, probably text.  A typical cluster would have multiple
> resources (more than two), one resource per node and one extra node.

I was facing a similar issue, but instead of going for full cluster stack (i 
didnt need it for the failover), I went for csync2

if you absolutely need to have the changes propagated instantly, you need to 
hook csync2 to inotify (google should give you options), or if you dont expect 
any changes right before crashes, running with cron every few minutes might 
suit your needs

Regards
Pavel Herrmann

> 
> Ideas?
> 
> Could I use the CIB directly to replicate data?  Use cibadmin to update
> something and sync? How big can a resource parameter be?  Could a resource
> modify its parameters so that they are replicated throughout the cluster?
> Is there a simple file replication Resource Agent?
> Drdb seems like overkill.
> 
> Regards.
> Mark K Vallevand  
> Mark.Vallevand at Unisys.com<mailto:Mark.Vallevand at Unisys.com> May you live in
> interesting times, may you come to the attention of important people and
> may all your wishes come true. THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL
> AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the
> intended recipient. If you received this in error, please contact the
> sender and delete the e-mail and its attachments from all computers.