Re: Disaster planning advice needed.

Hi,

It really depends upon your Goals. Is uptime strictly the concern? Or is distributing user load?
From your message, it looks like concern for hardware failure is really the primary concern. In that case, hot backups are not enough -- what are you going to use the hot backups with when you server is down because of a hardware failure?

In general, I would not look at replication for simply disaster recovery. There is more to replication than just turning it on -- such as how to handle conflict resolutions between two database (in async replication). If the application was built without replication in mind, this could be a nightmare! (Such as Sequences & Primary Keys) Also, you MUST consider periodic re-instantation (re-synchonizing replicated objects) of the two databases to ensure data concurrency? All this requires an extensive data analysis and this costs $$$$

Hot backups and periodic cold backups are a start and always good DBA practices, but from reading your message they are not enough. Have you looked into the prospect of using a Standby-Database on a remote server? This could be a more cost effective solution and can meet the criteria of becoming available when the main site goes down (with some minor manual intervention).

Good Luck,
darryl dB Balaski
www.rdbms.org (it will be up in a month)

"Greg C." wrote:

> Hello, Could you please give me some guidance as to how I should approach
> disaster planning. I am about to begin a new position with a new company.
> I will be working on designing a disaster recovery plan. My new company
> is trying to use multimaster replication for this. The failover will only
> become available to users when the primary fails. No users will be
> attached to the failover while the primary is active. In the event of a
> failure the failover site is to become the primary. The fail over site does
> not reside in the same location as the primary db.
>
> My opinion is that we should use a hot backup site for this scenario. Can
> you also comment about this plan?
>
> How are others approaching this situation? What are the trade offs
> between a hot standby and multimaster replication? What is the downside to
> either approach?
> Are there any third party tools to help in maintaining a hot standby
> database?
>
> Thank you for your help.
Received on Wed Feb 03 1999 - 14:24:45 CST