Jim,
This problem is the result of the fact there are two users with the
same username (for this "Domain Coordinator" account) in the pitt
domain.
The home server for the original one is the physics server (pittphyast1).
That DC user must also have been assigned an authoring role at some
point, and either your colleague was logged in as that user when
authoring those resources, or a co-author role was assigned, and the
co-author role was used when creating them.
More recently an identical username was assigned to a new user on the
second library server/VM (pittmath2) added this summer (in Math) to
the pitt LON-CAPA domain.
Ordinarily, LON-CAPA will prevent creation of duplicate usernames on
different library servers in the same domain. However, there is an
exception when make_domain_coordinator.pl is run from the command line.
My assumption is that make_domain_coordinator.pl was run on the new
pittmath2 library server, and unfortunately the username chosen for
the new Domain Coordinator was the same as the one which already
existed on pittphyast1.
What happens then, when you attempt to browse this user's directory in
/res/pitt/XXXXXX, is that LON-CAPA first checks the homeserver for the
user, and it accepts the first "found" result, which comes from
pittmath2. (The result is also cached in %homecache in an Apache child).
LON-CAPA then requests a directory listing from
/home/httpd/html/res/pitt/XXXXXX on pittmath2, but finds nothing there
- hence "Directory does not exist" is reported.
The same occurs when other servers (excluding pittphyast1) attempt to
display published resources from /res/pitt/XXXXXX.
If the server doesn't already have the resources, then it will contact
the author's homeserver to subscribe, and then, once subscribed, the
content will be replicated from pittphyast1 to the other server.
In this case, though, it is contacts pittmath2 (the author's
homeserver), but that server doesn't have the content, so it can't be
replicated.
The solution to this is for the system administrator in Math to use
the command line on pittmath2 to:
(a) Run expire_DC_role.pl to expire the DC role for the XXXXXX:pitt
user on pittmath2.
(b) Delete the XXXXXX user from /home/httpd/lonUsers/1/2/3/XXXXXX
(where 1,2, and 3 are the first three characters in the XXXXXX
username).
(c) Run make_domain_coordinator.pl on pittmath2, if a second Domain
Coordinator account is needed, (or run
add_domain_coordinator_privilege.pl on pittmath2 to assign a DC role
to an existing user, for which pittmath2 is the home server).
After reload of the Apache web server on each of the LON-CAPA servers
in the pitt domain, then the homeserver for the XXXXXX:pitt user will
be correctly identified as pittphyast1, and the directory
/res/pitt/XXXXXX will no longer be reported as non-existent, and
content will be replicated from there to other servers hosting
sessions for pitt users.
One thing I found in doing this was that the math IT person, has
moved the math server over to a vm on a machine in the universities
data center. This allows them to use the university single login
rather than the local login that is used by the physics servers.
From a technical standpoint it seems to me that use of Shibboleth
authentication can easily be supported for all pitt users by requiring
log-in to LON-CAPA via https://homework2.math.pitt.edu (which has
Shibboleth installed) as long as the usernames used for users for whom
pittphyast1 is the homeserver are standard Pitt Passport usernames.
(For non-standard usernames the URL: /adm/login, i.e., non-SSO log-in,
would need to be used).
From a purely technical standpoint, it would make sense to make
pittmath2 an access server, and also configure it as a LON-CAPA load
balancer for the pitt domain. If that were done, resources allocated
to the VM could be reduced significantly. If any users have been
created on it in /home/httpd/lonUsers/pitt they could be moved to
pittphyast1.
There may be other (non-technical) reasons why the two departments
wish to run their own library servers within the pitt LON-CAPA domain,
and LON-CAPA is also perfectly able to support that configuration
(just don't duplicate usernames on the two library servers when
creating users via the command line).
Stuart Raeburn
LON-CAPA Academic Consortium
Quoting "Mueller, James A." <muel...@pitt.edu>:
Stuart,
Thanks for the very detailed instructions. I now have a related
problem and some understanding of what might have been the cause of
my problem before.
There are a set of .problem files that were written 7-8 years ago by
a professor who has since retired. What is strange is that he did
not create these under his own author area but somehow in an area I
would associate with the domain coordinator ?/res/pitt/XXXXXX?
where XXXXXX is the username for the domain coordinator. Now we
have just been cloning the course every year, and that works fine
from the physics server, but they cannot be seen from the math
server. Thus cloning failed when run from the math server.
Now that the course is set up, I see students who end up on the math
server still can?t view those problems. From the physics server,
for students in my course, they click on the problem and all is
fine. But if they are on the math access server, they see an error
message like ?Unable to find MeteoroidsInertial.problem?.
In addition, if as course coordinator I try to browse resources
(from either server), it shows and Area XXXXXX under /res/pitt, but
if I click on it, it says ?Directory does not exist?. On the other
hand, I can log into the library server, do an ls on that area
(/home/httpd/html/res/pitt/XXXXXX?) and see all the files. So I
guess I need to copy all the .problem files over to a valid author
area (mine probably), republish them, and move the links in my
course to new versions of the problems for future terms.
One thing I found in doing this was that the math IT person, has
moved the math server over to a vm on a machine in the universities
data center. This allows them to use the university single login
rather than the local login that is used by the physics servers.
Probably not a good idea to have the math access server run
differently from the physics access and library servers, so that is
something we should probably standardize in the near future.
-Jim
_______________________________________________
LON-CAPA-users mailing list
LON-CAPA-users@mail.lon-capa.org
http://mail.lon-capa.org/mailman/listinfo/lon-capa-users
