[LON-CAPA-admin] mixing 32 bit and 64 bit servers

Gerd Kortemeyer korte at lite.msu.edu
Thu Oct 16 13:12:20 EDT 2008


Hi,

No, it isn't a problem to run 32-bit and 64-bit machines within the  
same domain.

However, a 32-bit server could not act as a "hot-spare" for a 64-bit  
machine and vice-versa (i.e., you cannot exchange disks between the  
machines if one fails), as the database files (".db"-files) are  
incompatible; in normal LON-CAPA operations, that is not an issue,  
since all communication goes through the LON-CAPA network processes.

- Gerd.

On Oct 16, 2008, at 12:25 PM, Bob Gonzales wrote:

> Is it possible to use 32 bit servers and 64 bit
> servers in the same domain?  I have a library server
> and an access server both using Fedora 64 bit and I
> would like to add another access server but the
> only machine I have available would have to run
> Fedora 32 bit.
>
> Thanks,
> Bob Gonzales
> Binghamton University
> Chemistry Dept
>
> -----Original Message-----
> From: lon-capa-admin-admin at mail.lon-capa.org
> [mailto:lon-capa-admin-admin at mail.lon-capa.org] On Behalf Of Stuart  
> Raeburn
> Sent: Wednesday, October 15, 2008 12:08 PM
> To: lon-capa-admin at mail.lon-capa.org
> Subject: RE: [LON-CAPA-admin] access server questions
>
> Bob,
>
> I have identified the reason why you cannot see remote resources from
> your access server.
>
> Currently binghamtona2 is no longer included in the dns_hosts.tab file
> installed on one of the LON-CAPA DNS servers, because an update to
> LON-CAPA 2.7.1 (released 9/25) on that particular server on 10/6
> overwrote the more recent file (which included binghamtona2)
> previously installed on the server on 10/2.  As a consequence other
> servers in the cluster will not permit connections if their hosts
> information (cached for 24 hours) was retrieved from this particular
> LON-CAPA DNS server.
>
> I have contacted the system administrator for the particular DNS
> server and requested an update to the dns_hosts.tab file.  Assuming
> the DNS server is updated today, binghamtona2 should be able to see
> resources again after 5 am tomorrow, once cached hosts tables on
> remote servers have been refreshed.
>
> Stuart Raeburn
> MSU LON-CAPA group
>
>
> Quoting Bob Gonzales <rgonzal at binghamton.edu>:
>
>> Update:  The IT guy looked at the firewall and found that the
>> library server had been removed from the list.  So, he added it
>> back and we seem to be good.  I can log into the Binghamton domain
>> from msu.
>>
>> However, I still cannot see remote resources from my access server.
>>
>> I got a note from Gerd about an update the dns tables for another
>> access server I am going to be installing.  Here's part of what he  
>> sent:
>>
>>>
>>> Index: loncom/production_dns_hosts.tab diff -u
>>> loncom/production_dns_hosts.tab:1.47 loncom/
>>> production_dns_hosts.tab:1.48
>>> --- loncom/production_dns_hosts.tab:1.47	Thu Sep 25 23:15:14 2008
>>> +++ loncom/production_dns_hosts.tab	Wed Oct 15 09:04:29 2008
>>> @@ -94,6 +94,7 @@
>>> ufml1:ufm:library:lon-capa-base1.server.uni-frankfurt.de:https
>>> binghamtonl1:binghamton:library:loncapa.chem.binghamton.edu
>>> binghamtona2:binghamton:access:loncapa2.chem.binghamton.edu
>>> +binghamtona3:binghamton:access:loncapa3.chem.binghamton.edu
>>> itul1:itu:library:www.fizikodev.itu.edu.tr
>>> uprml1:uprm:library:loncapa.hep.uprm.edu
>>> casel1:case:library:capa1.chem.cwru.edu
>>
>> Should I be able to see the access server that is already supposed  
>> to be
>> in the cluster, binghamtona2, in my local dns_hosts.tab files?   
>> Currently,
>> it doesn't appear in either my binghamtonl1 library server's file  
>> or the
>> binghamtona2 access server's file.
>>
>> Sorry if this is a dumb question or observation.
>>
>> Thanks,
>> Bob Gonzales
>> Binghamton University
>> Chemistry Dept
>>
>> -----Original Message-----
>> From: lon-capa-admin-admin at mail.lon-capa.org
>> [mailto:lon-capa-admin-admin at mail.lon-capa.org] On Behalf Of Stuart
> Raeburn
>> Sent: Tuesday, October 14, 2008 11:29 PM
>> To: lon-capa-admin at mail.lon-capa.org
>> Subject: RE: [LON-CAPA-admin] access server questions
>>
>> Bob,
>>
>> Curiously, it looks as though inbound traffic to port 5663 is being
>> blocked on your library server. nmap reports:
>>
>> Interesting ports on loncapa.chem.binghamton.edu (128.226.130.107):
>> PORT     STATE    SERVICE
>> 5663/tcp filtered unknown
>>
>> whereas port 5663 seems to open for inbound traffic on your access  
>> server:
>>
>> Interesting ports on loncapa2.chem.binghamton.edu (128.226.130.9):
>> PORT     STATE SERVICE
>> 5663/tcp open  unknown
>>
>> This is not consistent with the report that remote resources are
>> accessible on the library server but not on the access server.
>>
>> You should try in turn on each server to see if connection is  
>> possible
>> to the other server via port 5663.
>>
>> On 128.226.130.107
>> telnet 128.226.130.9 5663
>>
>> On: 128.226.130.9
>> telnet 128.226.130.107 5663
>>
>> You can also use:
>>
>> iptables --list
>>
>> to see whether the Fedora firewall is open for port 5663:
>>
>> e.g.,
>> ACCEPT     tcp  --  anywhere             anywhere            tcp  
>> dpt:5663
>>
>> Blocking inbound and/or outbound traffic may be occurring elsewhere  
>> in
>> the network.
>>
>> I am currently unable to start a session with a user in the msu  
>> domain
>> on either server.
>>
>> Stuart Raeburn
>> MSU LON-CAPA group
>>
>>
>> Quoting Bob Gonzales <rgonzal at binghamton.edu>:
>>
>>> lon-capa-admin at mail.lon-capa.org
>>>
>>> I made the changes outlined below, renaming my access server to
>>> what was entered in the loncapa DNS tables, and I was able to
>>> see remote resources in one of my homework sets from my access
>>> server.  I only checked that one.
>>>
>>> Today, I went to check some other homework sets and I cannot see
>>> any of those remote resources (I get a message "Unable to Find...).
>>> I can still see the resources in the original set that I checked
>>> last week.
>>>
>>> On my library server I can see all the remote resources in all of
>>> my sets and I can browse to them via "Edit Course->Import".
>>>
>>> What can I check to help track down the problem?
>>>
>>> Thanks,
>>> Bob Gonzales
>>> Binghamton University
>>> Chemistry Dept
>>>
>>> -----Original Message-----
>>> From: lon-capa-admin-admin at mail.lon-capa.org
>>> [mailto:lon-capa-admin-admin at mail.lon-capa.org] On Behalf Of Stuart
>> Raeburn
>>> Sent: Saturday, October 04, 2008 5:14 PM
>>> To: lon-capa-admin at mail.lon-capa.org
>>> Subject: Re: [LON-CAPA-admin] access server questions
>>>
>>> Bob,
>>>
>>> Although the LON-CAPA cluster tables have been updated on the LON- 
>>> CAPA
>>> "DNS" servers run by the LON-CAPA Academic Consortium, connections
>>> between your new server and other servers in the LON-CAPA network  
>>> and
>>> are failing because there is a mismatch between the lonHostID used  
>>> by
>>> your new server, and the lonHostID included in the record added to  
>>> the
>>> hosts table on 9/26.  This is the current entry in the dns_hosts.tab
>>> file:
>>>
>>> binghamtona2:binghamton:access:loncapa2.chem.binghamton.edu
>>>
>>> The login page for your new server reports:
>>> Domain:    	 binghamton
>>> Server:  	 binghamtona1 (access)
>>>
>>> The simplest thing would be for you to modify the lonHostID in:
>>> /etc/httpd/conf/loncapa.conf
>>>
>>> and the last line in /home/httpd/lonTabs/hosts.tab
>>> on loncapa2.chem.binghamton.edu
>>>
>>> so the new server is known as binghamtona2 everywhere.
>>>
>>> If you also added an entry for the access server to
>>> /home/httpd/lonTabs/hosts.tab on your library server
>>> (loncapa.chem.binghamton.edu)
>>> so the two servers could communicate with each other before the
>>> central dns_hosts tables had been updated you should modify that  
>>> too.
>>> If you hadn't added a line to hosts.tab on your library server you  
>>> can
>>> ignore this last part.
>>>
>>> You'll need to use:
>>>
>>> /etc/init.d/loncontrol restart
>>> /etc/init.d/httpd restart
>>>
>>> on your access server after you've made the change.
>>>
>>> The alternative to this would be to leave the entries on your own
>>> server(s) unchanged, and have the entry in the central DNS cluster
>>> tables changed to:
>>> binghamtona1:binghamton:access:loncapa2.chem.binghamton.edu.   
>>> However,
>>> this will likely involve a greater delay because your server would
>>> only be able to connect to the network once the updated  
>>> dns_hosts.tab
>>> file had been propagated to the LON-CAPA "DNS" servers at MSU, UIUC
>>> and SFU.
>>>
>>> I checked ports 80, 8080 and 5663 for inbound TCP/IP traffic to your
>>> new acces server.  All looks good.
>>>
>>> loncapa2.chem.binghamton.edu (128.226.130.9):
>>> PORT     STATE SERVICE
>>> 5663/tcp open  unknown
>>> 8080/tcp open  http-proxy
>>> 80/tcp open  http
>>>
>>> Stuart Raeburn
>>> MSU LON-CAPA group
>>>
>>>
>>> Quoting Bob Gonzales <rgonzal at binghamton.edu>:
>>>
>>>> I've got a new access server in the domain.  I've
>>>> been told it is in the cluster tables but it will
>>>> take a while to propagate around.  It's been a week
>>>> now.  How long does this usually take?
>>>>
>>>> When I log directly into the access server as a
>>>> course coordinator and go to edit contents
>>>> and go to import, I can see all of the domains but
>>>> clicking on a domain doesn't show me any resources,
>>>> it just turns the little arrow to point down without
>>>> showing anything from that domain.
>>>>
>>>> Likewise, if I log directly into the access  server as
>>>> a student I can't see any of the resourses that are not
>>>> in my domain.  For a composite page, wherever there is a
>>>> non-local resource I have the title of the resource displayed
>>>> and the words "Not available" displayed above it.
>>>>
>>>> My computer center has opened the 5663 and 80 for the
>>>> IP of the access server, 128.226.130.9, but if someone
>>>> would like to confirm that the ports are open for me that
>>>> might be helpful.
>>>>
>>>> Any other help would be appreciated, even if you just
>>>> tell me to be patient.
>>>>
>>>> Bob Gonzales
>>>> Binghamton University
>>>> Chemistry Dept
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> LON-CAPA-admin mailing list
>>>> LON-CAPA-admin at mail.lon-capa.org
>>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>>>
>>
>>
>
>
>
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