[LON-CAPA-admin] library server problem

[Stuart Raeburn]

Bob,

> My loncapa library server (loncapal1.chem.binghamton.edu) doesn't appear to
> be working properly.

It looks as though your server is back up (as of 9am EST, 11/11), so  
you were evidently able to resolve the issues you had encountered  
yesterday.

> Earlier today I applied centos updates to serveral of my access servers,
> not the library server.  It took about 30 minutes for loncontrol to start
> up when I rebooted them.

Slow start times for loncontrol usually mean that something is amiss  
with domain name resolution on your server.

Your lonnet.log shows logging entries spread over several minutes reporting:
"no IP found" for a number of hostnames for LON-CAPA servers.

Although a handful of these are the usual suspects (i.e., servers for  
which IP mapping will always fail because use of the server has been  
discontinued), I see at least three for which IP <-> hostname mapping  
is definitely available:

homework.phyast.pitt.edu no IP found
naua0.chm.nau.edu no IP found
loncapa.mit.edu no IP found

The issue can occur if DNS service is unavailable.  Checking the  
contents of /etc/resolv.conf is a good starting point.

There can also be issues on a specific server (server cannot talk to  
itself via the LON-CAPA daemons) if the IP of the server reported by:

/sbin/ifconfig

does not match that retrieved from DNS resolution for the hostname  
specified for your server in /home/httpd/lonTabs/hosts.tab

> So, I tried logging directly onto my library server and I get the page that
> says "This LON-CAPA server is temporarily not available for login".
>  Restarting the httpd and lon daemons takes about 30 minutes here too and I
> still get that page.

The log messages include several "WARNING: A socket timeout was  
detected" followed by "WARNING Shutting down a socket".

I also see a number of instances of:

Attempted insecure connection disallowed
Rejected client 128.226.130.234, closing connection
CRITICAL: Disconnect from 128.226.130.234 (binghamtona7)

which suggests there might either be an issue with reverse DNS, or  
that you have other than values of 1 (the default) set for:

PerlSetVar     loncAllowInsecure
PerlSetVar     londAllowInsecure

in /etc/httpd/conf/loncapa.conf

but you do not have certificates signed by the LON-CAPA Certificate  
Authority installed.  (See the section: "Internal LON-CAPA SSL" in the  
Domain Coordination manual, e.g.,

https://s10.lite.msu.edu/adm/help/Domain_Configuration_SSL.hlp

for more information).


Stuart Raeburn
LON-CAPA Academic Consortium


Quoting Bob Gonzales <rgonzal at binghamton.edu>:

> My loncapa library server (loncapal1.chem.binghamton.edu) doesn't appear to
> be working properly.
>
> Earlier today I applied centos updates to serveral of my access servers,
> not the library server.  It took about 30 minutes for loncontrol to start
> up when I rebooted them.  When it did finally finish booting I could log in
> and get to the roles screen but when I choose a course I get
>
> "The following problems occurred:
> Map not loaded: The file
> /home/httpd/html/userfiles/binghamton/9N542115927ff4fbcbinghamtona3/default.sequence
> does not exist."
>
> So, I tried logging directly onto my library server and I get the page that
> says "This LON-CAPA server is temporarily not available for login".
>  Restarting the httpd and lon daemons takes about 30 minutes here too and I
> still get that page.  I'm not sure what to check next.  The library server
> did not get any centos updates applied today.  It was only rebooted.
>
... many log lines removed here ...
>
> I've been down all afternoon and evening so any help would be greatly
> appreciated.
>
> Thanks,
> Bob Gonzales
> Chemistry Dept
> Binghamton University
>