[LON-CAPA-admin] Hostname change

[Stuart Raeburn]

Richard,

You can change the hostname of a library server, but you should avoid  
changing  the lonHostID.  So, for your library server in the purdue  
domain, the lonHostID should remain as purduel1.

Let's say you decide to assign a hostname of loncapa01.purdue.edu to  
the new library server.

You will need to modify /home/httpd/lonTabs/hosts.tab to replace

purduel1:purdue:library:loncapa.purdue.edu:https:purdue.edu

with

purduel1:purdue:library:loncapa01.purdue.edu:https:purdue.edu

(If you like you can also make the same change to  
/home/httpd/lonTabs/dns_hosts.tab on all nodes in your domain, but  
that file is only consulted if none of the LON-CAPA "DNS" servers at  
MSU, UIUC or SFU are contactable).

Depending on when you make the change to hosts.tab and restart the  
LON-CAPA daemons and the web server, there could be up to 24 hours  
when your library server will not be able to connect to other servers  
in the network.

You can minimize the length of time without connectivity by switching  
the library server's hostname, and restarting the daemons, shortly  
before 5.10 am EST.  Other servers in the network will run  
/home/httpd/perl/loncron as user www at 5.10 am local time (and the  
majority of LON-CAPA servers are in US time zones) to update their  
cluster information.

If you let me know the evening before you make the change then I will  
update the "DNS" servers at MSU, UIUC and SFU with an updated  
dns_hosts.tab, so that when loncron next runs on each server in the  
network, the hostname <=> lonHostID mapping for your library server  
will reflect the new configuration.

At that time I would also include the new record for the load balancer, e.g.,
purduea6:purdue:access:loncapa.purdue.edu:https:purdue.edu in the  
updated dns_hosts.tab files on the msu, uiuc and sfu library servers.


Stuart Raeburn
LON-CAPA Academic Consortium


Quoting "Lucas, Richard" <clucas at purdue.edu>:

> We currently use our library server (loncapa.purdue.edu) as a load   
> balancer. We would like to add another node to do load balancing and  
>  move our library server to more of a backend role. However, we  
> would  like to retain the loncapa.purdue.edu for the load balancer.  
> In  order to accomplish this I would like to change the hostname of  
> our  library server. What is needed to accomplish this without  
> messing up  the connections to the LON-CAPA network?
>
> Thanks,
> Richard