Re: [SAGE] number of eggs in a basket

[nmedbery@museverte.net]

Not to mention that even one service (whether it be web, nis, etc. or 
different instances of one of those) will usually have multiple 
environments for development, acceptance testing, and production.  At 
least the acceptance environment should have the same redundancy as 
production to make sure the given application/service functions in that 
specific configuration.  This may have been touched on already, sorry if I 
missed it.

At my last job, we had such a three tier system and redundancy was built
into both acceptance and production (duh).  We had a large room full of
machines providing roughly the 12-20 services referred to by other people.  
I swear they were breeding down there!  And that was with redundancy for 
a select few services!

	-Nate

On Fri, 7 Jan 2005, Richard Chycoski wrote:

> In a large organisation, any of these individual services can become 
> multiples - for instance we have more than 20 NIS+ domains, all running 
> as separate services. Five of the masters are hosted in one DC.
> 
> DNS can also become multiple if different servers support different 
> domains or subdomains. Computational resources are often divided at the 
> machine (or cluster of machine) level for different groups of engineers, 
> and each is treated as a separate service. Databases are usually 
> separate servers, and we have hundreds of database servers.
> 
> Different web services really are different services - sometimes out of 
> the necessity of isolating the environment for each web service.
> 
> Distinct services should be defined by their distinct environments - 
> running multiple instances of a single kind of service (that each 
> require their own environment and/or redundancy) is the same as running 
> multiple *kinds* of services, except that you should be able to scale 
> better if you plan the services properly (e.g., if you have 20 virtual 
> web environments each running on a dozen different servers, you may only 
> need one or two extra servers for redundancy rather than another dozen).
> 
> - Richard
> 
> 
> Joseph S D Yao wrote:
> 
> >On Fri, Jan 07, 2005 at 10:28:00AM -0800, Richard Chycoski wrote:
> >  
> >
> >>If you are virtual web hoster you might have a seperate web 'service' 
> >>for each client. ...
> >>    
> >>
> >
> >...
> >
> >The original poster mentioned "services" such as ... Web, DNS, NIS, and
> >NFS.  By this definition, the above qualifies as one, or part of one.
> >
> >However, different Web apps might (MIGHT) qualify as different services.
> >As I think you said, it depends on your business.
> >
> >  
> >
>