[LINK] RFC: Cloud Computing

[Bernard Robertson-Dunn]

Roger Clarke wrote:
> At 9:54 +1100 24/11/09, Bernard Robertson-Dunn wrote:
> ...
>   
>> Cloud environments might be OK for isolated applications, but 
>> extending your operational environment into a cloud is fraught with 
>> both problems and risks.
>>     
>
> Among other things, I'm going to have to do some differentiation 
> between applications, based on their importance.
>
> The 'mission-critical' jargon is dopey (an inappropriate import from 
> military contexts, where it *does* make sense).
>
> But some concept may be needed such as 'capable of bankrupting me if 
> it goes wrong', to distinguish from 'would be a handy adjunct to our 
> marketing analysis' and 'can go missing for a few days and it won't 
> matter much'.
>   
You could work off the Uptime Institute's data centre tier definitions. 
They start with the data centre and work up to the business. They relate 
data centre facilities to business requirements but the differentiators 
might be useful.

The Uptime Institute likes to be paid for their material, but here's an 
analysis/extract that's been done that you might find useful. They don't 
mention security or systems integration issues, so these dimensions are 
not covered.

Tier 1 is appropriate for applications to support organisations which :-
* do not have an established revenue stream or
* do not have an identifiable financial impact of disruption due to data 
centre failure, or
* have a low availability requirement, such as a 5.0/5.5 day business week.

Tier 2 is appropriate for:-
* call centres, where multiple sites are available
* businesses linked to traditional business hours or
* organisations which don’t have online service delivery obligations or
* organisations without real time service delivery obligations.

Tier 3’s typical applications have:-
* quality of service commitments with serious financial ramifications
* high-end availability requirements for ongoing business or
* identified a significant cost of disruption from a planned data centre 
shutdown.
* to support internal and external clients 24x7; including service 
centres and help desks, spanning multiple time zones, with clients and 
employees spanning regional areas

Tier 4 is justified for:-
* organisations with an international market presence in a 
highly-competitive client-facing market space or
* organisations where processes are continuous – inbound/outbound transfers
* businesses based upon eCommerce, market transactions or financial 
settlements processes
* global organisations where client access to applications and employee 
exploitation of information technology is a competitive advantage
* internet based organisations or co-location providers who have quality 
of service commitments with serious financial ramifications
* organisations who have extremely high availability requirements for 
ongoing business or
* organisations for whom there is a profound and clearly identifiable 
cost of disruption due to data centre shutdown.

-- 
 
Regards
brd

Bernard Robertson-Dunn
Canberra Australia
brd at iimetro.com.au