Re: HA Clustering with RAC
Date: Thu, 18 Mar 2004 15:12:33 +0100
Message-Id: <4059ae36$0$13855$ba620e4c_at_news.skynet.be>
Ulf wrote:
> Hi guys,
> I'm writing my diploma thesis about Disaster Recovery. I try to differ
> types of cluster depending of the layer where they are realized.
> Here is my point of view:The aim of a cluster is, that there is an
> automatic failover of resources to the secondary site that no
> transaction is lost.This means that the OS, the database and the
> application (e.g. SAP R/3) must be active on the secondary site.
that's a high availability cluster (with failover: two machines, checking
each other's health, and the other taking over when one fails)
you also have load-balancing clusters (for scalability, reliability,
resilience)
good book: "Load balancing servers, firewalls and caches" from Chandra
Kopparapu
good site: linux-ha.org
interesting project to give you insight in the material: linux virtual
server.
it's a very interesting topic, but overwhelming at the start (many complex relationships between different aspects of a computer system)
linux is ideal to experiment with such techniques.
> Here are my questions:
> On which layer (OS,DBMS,Application) is the failover realized? Can it
> be realized on different layers?Which application does support this
> function? Or have all applications to support this function?
> Do you always need a special cluster software like HACMP?
>
> I would be glad, if you could answer my questions and give me links
> where I can read something about this.
>
> Bye
Received on Thu Mar 18 2004 - 15:12:33 CET