[LON-CAPA-admin] Adding Access servers

[Todd Ruskell]

Mark (and likely Guy),

Thanks for the solution below.  I took Mark's implementation to our network 
folks, and got this positive response with a caveat:

> We can and will support the round-robin scheme for resolving IP 
> addresses.  I should say I've never done it, so I'm not sure exactly 
> what all the possible gotchas are, but it's pretty standard practice and 
> should work.
> 
> We can't however accomplish this the way you describe.  The feature 
> (actually it was considered a bug) that allowed an alias to point to 
> multiple systems ad described in the quote you sent was removed/fixed in 
> recent version of BIND.
> 
> The approved method of achieving the same result is to have multiple 
> hosts that actually have the same hostname.  That is we could have two 
> hosts defined with the name "loncapa.mines.edu", each with different IP 
> addresses.

So this brings me to questions probably for Guy:  

The hosts.tab file contains hostnames, LON-CAPA names, and IP addresses.  
1) Will LON-CAPA choke if two IP addresses have the hostnames?  
2) Should we then give our access servers the same, or different, LON-CAPA 
names?  
3) Or is there some other way to manifest the load-balancing that I should 
point our network folks to?

Thanks for your help.  I'm learning more about the inner workings of 
load-balancing than I ever thought I would, but that's a "good thing".


Todd

> > We have defined an alias, loncapa.phy.ohiou.edu, that has two references 
> > in the Domain Name server. DNS hands out the name in a round-robin 
> > fashion. This does a pretty good job of evening the load. Once the student 
> > is logged into a particular server, they stay on that server.



-- 
Dr. Todd Ruskell
Lecturer, Department of Physics              Office:  Meyer Hall 326
Colorado School of Mines                     Phone: 303-384-2080
1523 Illinois Street                         Fax: 303-273-3919
Golden, CO 80401