[LON-CAPA-admin] Published resources not showing up on access servers

Stuart Raeburn raeburn at msu.edu
Sat Sep 19 12:15:21 EDT 2015


Bob,

> The subscription file shows the access server is subscribed.
>   binghamtona2:128.226.130.9:1442502030

The timestamp 1442502030 converts to: Thu Sep 17 11:00:30 EDT
( http://www.epochconverter.com/ )

which is after the (Thu Sep 17 10:49:37 EDT) time of the:
"access failed for 128.226.130.9, reason: binghamtona2 not subscribed"  
message.

You might check that your servers are all running ntpd, and have the  
correct date/time.

It is possible that if binghamtona2 had already been subscribed at  
10:49:37, you could still see an error message: "binghamtona2 not  
subscribed", if there whad been a problem with the DNS look-up on your  
library server for the hostname: loncapa2.chem.binghamton.edu.

lonracc.pm which authorizes access to files in /raw/ includes:

my (undef,undef,undef,undef,$ip) = gethostbyname($hostname);
return 0 if (length($ip) != 4);
$ip=inet_ntoa($ip);

where $hostname would be loncapa2.chem.binghamton.edu and $ip would be  
128.226.130.9

It is possible then that there is a issue with the DNS service that is  
used to resolve the hostname: loncapa2.chem.binghamton.edu

> I see binghamton.edu in the dns_hosts.tab and and hosts.tab on the library
> server but I see chem.binghamton.edu in the access servers hosts.tab.  My
> dns domain is chem.binghamton.edu and I do remember using that during the
> installation on each machine this summer.  Could this be it?
>

The last entry in your server's record in hosts.tab is what is  
referred to in LON-CAPA as the "internet domain".  I do not believe  
that is the source of the problem here.  That value is used as a way  
to combine an institution's servers together into a group, if you have  
set the domain configuration to restrict user session hosting for  
users from domains outside your institution.  Although you should set  
it to be the same on all your servers, it does not currently play a  
role in controlling content replication.

So it should be set to binghamton.edu on all your servers. for  
consistency with what is present in the "authoritative" cluster  
tables, e.g., https://s10.lite.msu.eu/adm/dns/hosts

It would only make sense to set it to chem.binghamton.edu if another  
department at Binghamton installed LON-CAPA on their own servers, and  
you wanted to prohibit hosting of your user sessions on their servers,  
or vice versa.


Stuart Raeburn
LON-CAPA Academic Consortium


Quoting Bob Gonzales <rgonzal at binghamton.edu>:

> Stuart,
>
> In my library servier httpd error_log I see:
>
> [Thu Sep 17 10:49:37.441421 2015] [:error] [pid 2605] access to
> /home/httpd/html/raw/binghamton/gonzales/Testing Area/foobar.problem failed
> for 128.226.130.9, reason: binghamtona2 not subscribed
>
> The subscription file shows the access server is subscribed.
>
>   binghamtona2:128.226.130.9:1442502030
>
>
> Using the info in the referenced post
> http://mail.lon-capa.org/pipermail/lon-capa-admin/2013-November/002773.html,
> I'm thinking a name/ip problem.
>
> So, regarding entries in /etc/hosts, there are only the default ones for
> 127.0.0.1 and ::1 on all the machines.
>
> Looking at dns_hosts.tab  I see this on all the servers (access and
> library):
>
> binghamtonl1:binghamton:library:loncapal1.chem.binghamton.edu:http:
> binghamton.edu
> binghamtona2:binghamton:access:loncapa2.chem.binghamton.edu:http:
> binghamton.edu
> binghamtona3:binghamton:access:loncapa3.chem.binghamton.edu:http:
> binghamton.edu
> binghamtona4:binghamton:access:loncapa.chem.binghamton.edu:http:
> binghamton.edu
> binghamtona5:binghamton:access:loncapa5.chem.binghamton.edu:http:
> binghamton.edu
> binghamtona6:binghamton:access:loncapa6.chem.binghamton.edu:http:
> binghamton.edu
> binghamtona7:binghamton:access:loncapa7.chem.binghamton.edu:http:
> binghamton.edu
>
> Looking at hosts I see this on the library server:
>
> ^s10.lite.msu.edu
> ^dalton.chem.sfu.ca
> ^library1.lon-capa.uiuc.edu
> binghamtonl1:binghamton:library:loncapal1.chem.binghamton.edu:http:
> binghamton.edu
>
> and this on one of the access servers:
> ^s10.lite.msu.edu
> ^dalton.chem.sfu.ca
> ^library1.lon-capa.uiuc.edu
> binghamtona2:binghamton:access:loncapa2.chem.binghamton.edu:http:
> chem.binghamton.edu
>
> I see binghamton.edu in the dns_hosts.tab and and hosts.tab on the library
> server but I see chem.binghamton.edu in the access servers hosts.tab.  My
> dns domain is chem.binghamton.edu and I do remember using that during the
> installation on each machine this summer.  Could this be it?
>
> Thanks,
> Bob Gonzales
>
>
> On Thu, Sep 17, 2015 at 5:23 PM, Stuart Raeburn <raeburn at msu.edu> wrote:
>
>> Hi Bob,
>>
>> Looking at lonc.log on the MSU LON-CAPA library server s10 I see that the
>> run of /home/httpd/perl/loncron used to update connections and retrieve
>> updated cluster membership information failed to connect to binghamtona2 at
>> 5:11 am today.
>>
>> On the MSU library server ...
>>
>> Thu Sep 17 05:11:14 2015 (2148) [loncapa2.chem.binghamton.edu] [Thu Sep
>> 17 05:11:14 2015: Parent keeping the flock] <font color='red'>CRITICAL:
>> Forking server for loncapa2.chem.binghamton.edu</font>
>> Thu Sep 17 05:11:18 2015 (13722) [loncapa2.chem.binghamton.edu] [Thu Sep
>> 17 05:11:14 2015: Connected to loncapa2.chem.binghamton.edu] <font
>> color='red'>CRITICAL: Failed to make a connection with lond.</font>
>> Thu Sep 17 05:11:18 2015 (13722) [loncapa2.chem.binghamton.edu] [Thu Sep
>> 17 05:11:14 2015: Connected to loncapa2.chem.binghamton.edu] <font
>> color='blue'>WARNING: Failing transaction sethost</font>
>>
>> As a result the lonc status reported on s10 for
>> loncapa2.chem.binghamton.edu was:
>>
>> www      13722  2148  0 05:11 ?        00:00:00 lonc:
>> loncapa2.chem.binghamton.edu Connection count: 0 Retries remaining: 5 ()
>> Thu Sep 17 13:29:08 2015
>>
>> However, when I attempted to connect to binghamtona2 a few hours ago the
>> connection was successfully created:
>>
>> www      13722  2148  0 05:11 ?        00:00:00 lonc:
>> loncapa2.chem.binghamton.edu Connection count: 1 Retries remaining: 5
>> (insecure) Thu Sep 17 13:34:39 2015
>>
>> and I was able to transfer my user session there.
>>
>> From the lonc.log information on your library server ...
>>
>>    Thu Sep 17 11:05:19 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu Sep
>>> 17 10:53:24 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='green'>SUCCESS: Connection 1 to
>>> loncapa2.chem.binghamton.edu now ready for action</font>
>>>    Thu Sep 17 11:10:20 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 11:10:20 2015: loncapa2.chem.binghamton.edu Connection count: 1
>>> Retries
>>> remaining: 5 (insecure)] <font color='blue'>WARNING: Shutting down a
>>> socket</font>
>>>
>>
>> This indicates successful creation of a connection, and then shutdown 5
>> minutes later, as a result of pruning of idle connections (this is all as
>> expected).  The IdleTimeout hard-coded in /home/httpd/perl/loncnew is 5
>> minutes.
>>
>>    Thu Sep 17 10:53:24 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu Sep
>>> 17 10:42:10 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='yellow'>INFO: Resetting Connection
>>> Retries.</font>
>>>
>>
>> This occurs when &Apache::lonnet::reconlonc() sends "reset_retries".
>> &reconlonc($clientname) is called in lond when lond is connected by a known
>> client (excluding connections from itself).
>>
>>       Cleanup phase: Notifications
>>>
>>>      Notifying host binghamtona7:not_found
>>>      Notifying host binghamtona2:not_found
>>>
>>
>> The logged "not_found" messages originate from
>> lond::update_resource_handler() on the library server, and will be sent if
>> the old copy of the file which has just been republished is no longer
>> present on the access server.
>>
>> That can happen if the Linux OS on the access server was updated without
>> preserving the contents of /home/httpd/html/res/.  This is not an issue,
>> including the case where the access server had a subscription to the file
>> before the access server was updated/rebuilt.  When the file is requested
>> in a user session hosted on the access server it should be replicated to
>> the access server from the library server, as usual.
>>
>> However this:
>>
>>    Thu Sep 17 11:00:30 2015 (3908): <font color="blue">WARNING: LWP get:
>>> 403 Forbidden: /home/httpd/html/res/binghamton/gonzales/Testing
>>> Area/foobar.problem</font>
>>>
>>>
>> indicates that the replication failed.  You might check in the
>> corresponding Apache error_log file for the request for:
>>
>> GET /raw/binghamton/gonzales/TestingArea/foobar.problem
>>
>> from 128.226.130.9.
>>
>> See:
>>
>> http://mail.lon-capa.org/pipermail/lon-capa-admin/2013-November/002773.html
>>
>> for a discussion of things to check.  In that particular instance the
>> "Forbidden" error was caused by an incorrect IP address in /etc/hosts
>>
>> Stuart Raeburn
>> LON-CAPA Academic Consortium
>>
>>
>> Quoting Bob Gonzales <rgonzal at binghamton.edu>:
>>
>> Hi,
>>>
>>> I'm running 2.11.1 and centos 7.1 on all my servers.
>>>
>>> When I publish a resource and then try to access it on any of my access
>>> servers I get the message 'unable to find' and then the name of the
>>> problem
>>> just published.
>>>
>>> The subscription file for the problem shows the access server has
>>> subscribed.
>>>
>>> When I republished a file the log file for the problem I got the following
>>> information from the log file for the problem:
>>>
>>>       Cleanup phase: Notifications
>>>
>>>      Notifying host binghamtona7:not_found
>>>      Notifying host binghamtona2:not_found
>>>      Notifying course binghamton_71215825fc2344762binghamtonl1:ok
>>>
>>> I see a lot of these messages for binghamtona2 (loncapa2) in the library
>>> server lonnet.log
>>>
>>> Thu Sep 17 10:53:24 2015 (8257): Trying to reconnect lonc for
>>> binghamtona2 (
>>> loncapa2.chem.binghamton.edu)
>>>
>>> And these in the library servers lonc.log
>>>
>>>     Thu Sep 17 10:42:10 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:42:10 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='yellow'>INFO: Resetting Connection
>>> Retries.</font>
>>>    Thu Sep 17 10:53:24 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:42:10 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='yellow'>INFO: Resetting Connection
>>> Retries.</font>
>>>    Thu Sep 17 10:53:24 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:53:24 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='yellow'>INFO: Resetting Connection
>>> Retries.</font>
>>>    Thu Sep 17 10:53:24 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:53:24 2015: loncapa2.chem.binghamton.edu  Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='yellow'>INFO: Resetting Connection
>>> Retries.</font>
>>>    Thu Sep 17 11:05:19 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:53:24 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='green'>SUCCESS: Created connection 1 to host
>>> loncapa2.chem.binghamton.edu</font>
>>>    Thu Sep 17 11:05:19 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:53:24 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='yellow'>INFO: Connected to lond version:
>>> 489</font>
>>>    Thu Sep 17 11:05:19 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 10:53:24 2015: loncapa2.chem.binghamton.edu Connection count: 0
>>> Retries
>>> remaining: 5 ()] <font color='green'>SUCCESS: Connection 1 to
>>> loncapa2.chem.binghamton.edu now ready for action</font>
>>>    Thu Sep 17 11:10:20 2015 (3279) [loncapa2.chem.binghamton.edu] [Thu
>>> Sep
>>> 17 11:10:20 2015: loncapa2.chem.binghamton.edu Connection count: 1
>>> Retries
>>> remaining: 5 (insecure)] <font color='blue'>WARNING: Shutting down a
>>> socket</font>
>>>
>>> I also see this in the access servers lonnet.log:
>>>
>>>    Thu Sep 17 11:00:30 2015 (3908): <font color="blue">WARNING: LWP get:
>>> 403 Forbidden: /home/httpd/html/res/binghamton/gonzales/Testing
>>> Area/foobar.problem</font>
>>>
>>> I don't really know what all of this means.  Any help would be
>>> appreciated.
>>>
>>> Thanks,
>>> Bob Gonzales
>>> Binghamton University
>>> Chemistry Dept
>>>



More information about the LON-CAPA-admin mailing list