[LON-CAPA-admin] Map not loaded error and missing problems/sequence file

[Stuart Raeburn]

Eric,

One question here is: which server was the CC logged into when the  
particular folder was copied in DOCS?

For this particular case (where copying an existing folder failed)  
these warnings can be eliminated by clicking the "continue" link from  
the course initialization page which displays these "Map not loaded"  
messages and then via 'Edit Course' deleting the folders corresponding  
to these non-existent sequence files.

It should be apparent which are the folders for which copying failed  
because in the Navigate Contents page I would expect they would be  
designated by jigsaw piece icons, instead of folder icons.  Obviously,  
for each the url in the link for the jigswa piece should be checked  
against the names of the files generating the "Map not loaded"  
messages to check that the correct item has been identified before  
deletion. Name checking unfortunately will be somewhat painful given  
such a long file name (indicative of an extensive clone/copy history  
for the particular folder).

What happened here was that LON-CAPA updated the contents of the  
top-level sequence (default.sequence) with references to these  
"copied" folders, but the actual copying of the files had failed  
somewhere.

You'll find records in /home/httpd/perl/logs/lonnet.log on the server  
which was hosting the CC's session when copying failed, and possibly  
also in /home/httpd/perl/logs/lond.log on the library server if a  
problem occurred when trying to replicate the new sequence file from  
the server hosting the session to  permanent storage on the course's  
library server.

If the CC was logged into the library server when the copy folder  
action was carried out on the library server, your addition of a new  
access server and subsequent switching of IP addresses on the access  
servers would be unrelated to this copy failure.  However, if the  
session was hosted on one of the access servers it is possible I  
suppose that the library server could not connect to the access server  
where the copy occurred. This behavior would depend on the timing of  
propagation of DNS changes in your network, and the timing of  
refreshing of cached ip/host information used by the Apache children.

 From a LON-CAPA perspective it's clear that the return value of   
&Apache::lonclonecourse::writefile() needs to be checked in londocs.pm  
before updating the map into which the user was attempting to paste  
the copied file. This will be fixed for the next release.

Stuart Raeburn
MSU LON-CAPA group

Quoting Eric Harvey/FS/VCU <teharvey at vcu.edu>:

> Hi,
>
> Just added a new server to lon-capa at VCU and I'm wondering if that
> hasn't created a problem.
> I get this error while attempting to access a course on the new server or
> the library server.
> The actual file doesn't exist when I look for it at the command line on
> the library server.
>
> The following problems occurred:
> Map not loaded: The file
> /home/httpd/html/userfiles/vcu/7x23751c9d5a248edvcua1/default_121888532420408122049661886012210909623064612216167072554812223520052745012223628802987112228847403262012235880253271812241782867629122463704767051225464849592122605977910350122659821911240122710968986191227882594282761228426065.sequence
> does not exist.
>
> The instructor of the course writes:
> "When using the copy and paste command on the indicated directory, the
> problems inside the directory seemed to no longer exist.
> When I repeated the process this morning, the HW#14 directory successfully
> copied once and did not copy another time.
> So, it is not simply a corrupted directory.  I used all three servers and
> there was no particular pattern."
>
> Thanks,
> Eric Harvey
> VCU Learning Systems
>