[LON-CAPA-admin] Images not showing up in student view for some questions

Michael Dugdale michael.dugdale at johnabbott.qc.ca
Fri Oct 18 08:57:37 EDT 2013


Thanks again Mark,

We're running 1 library and 2 access servers --- the behaviour is repeatable on all of them.  Our access servers are a little bit of an unusual configuration (PPC64) so that's the first thing I checked: it's happening on our stock RedHat 5 X86_64 library server too.

I don't think it's a replication problem:  the file's on each of the servers, with modification dates that vary slightly (I'm interpreting that as an indicator of when the resource was replicated).

Hmm… interesting observation about the version #… hadn't noticed that.  It does seem strange.

On 2013-10-17, at 11:11 PM, Mark Lucas <lucasm at ohio.edu> wrote:

> Is it sometimes taking a while for things to get replicated over to the server if it's
> not already cached? How many different servers do your students log in on, just one?
> 
> The only other strange thing I see is Version: -1  for the image.
> Is that a stray hyphen or really minus one?  What does version -1 mean?
> 
> Later,
> Mark
> 
> On Oct 17, 2013, at 9:28 PM, Michael Dugdale wrote:
> 
>> Thanks for the observation ray.
>> 
>> 
>> It's strange that you can't see it.  We're not vcu so we're only seeing what's been published system-wide.  As course coordinator, it's visible.  Only student roles are being denied access.
>> 
>> Browsing to the image file, the meta-data page (copy/pasted below) has the line "Copyright/Distribution:	System wide - can be used for any courses system wide".  
>> 
>> Strange that you're not able to see it out west.
>> 
>> ---------------------------
>> 
>> Metadata
>> 
>> Untitled Resource
>> /res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG
>> Version: -1
>> 
>> Title:	 
>> Author(s):	Josephus Ferguson
>> Subject:	 
>> Keyword(s):	 
>> Notes:	 
>> Abstract:	 
>> Lowest Grade Level:	Not specified
>> Highest Grade Level:	Not specified
>> Standards:	 
>> MIME Type:	<jpg.gif> JPEG Image Document
>> Language:	Not set -
>> Creation Date:	Mon Jun 2 09:37:25 pm 2008 (EDT)
>> Last Revision Date:	Mon Jun 2 09:37:25 pm 2008 (EDT)
>> Publisher/Owner:	Bartlett zzEdmonds [s2bdedmo:vcu]
>> Copyright/Distribution:	System wide - can be used for any courses system wide
>> Custom Distribution File:	 
>> Source Available:	Closed - XML source is closed to everyone
>> Source Custom Distribution File:	 
>> Obsolete:	 
>> Suggested Replacement for Obsolete File:	 
>> 
>> 
>> 
>> On 2013-10-17, at 9:08 PM, Raymond Batchelor <batchelo at sfu.ca> wrote:
>> 
>>> Well, that particular image is not published system wide, because it does not appear on this side of the continent.
>>> :-)
>>> Perhaps the author (s2bdedmo:vcu) did not allow Sytemwide Copyright/Diustribution or did not yet publish it.  Better try to contact them.
>>> 
>>> 
>>> 
>>> 
>>> ----- Original Message -----
>>> From: "Michael Dugdale" <michael.dugdale at johnabbott.qc.ca>
>>> To: "list about administration and system updating" <lon-capa-admin at mail.lon-capa.org>
>>> Sent: Thursday, 17 October, 2013 17:52:40
>>> Subject: [LON-CAPA-admin] Images not showing up in student view for some	questions
>>> 
>>> 
>>> Hi, 
>>> 
>>> 
>>> Looking for some help here. A chemistry teacher has reported a number of cases where the images associated with a problem don't show up for students. It loads fine for course coordinators. It's just the images that are included in the problem that are not showing up; the rest of the problem loads fine. 
>>> 
>>> 
>>> Trying to open just the image in a new tab (as student) gives the following error: 
>>> 
>>> 
>>> ----------------------------- 
>>> LON-CAPA Access Control 
>>> 
>>> 
>>> Access : Browse resources 
>>> Resource: /res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG 
>>> Action : Access Denied 
>>> Sorry ... 
>>> This action is currently not authorized. 
>>> ------------------------------ 
>>> 
>>> 
>>> I've looked in the file system, and the files are there, owner/group are www:www with permissions -rw-r--r-- 
>>> 
>>> 
>>> As far as Apache logs go, I see many remarks of the form: 
>>> 
>>> 
>>> [Thu Oct 17 20:23:36 2013] [error] access to /res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG failed for 74.57.249.17, reason: Access Denied for michaeldugdale domain johnabbott access bre 
>>> 
>>> 
>>> Trying to get a sense of what's going on, I checked the problem file on the server's file system and it does, indeed have the line 
>>> <allow src="/res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG"/ > 
>>> 
>>> 
>>> And I've double-checked that SELINUX is disabled... 
>>> 
>>> 
>>> I'm fresh out of ideas about where to look next. Does anyone have any thoughts on where I should look? 
>>> 
>>> 
>>> Thanks in advance, 
>>> 
>>> 
>>> Michael Dugdale 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> Michael Dugdale 
>>> Co-chair (Scheduling) 
>>> Department of Physics 
>>> John Abbott College 
>>> 21,275 Lakeshore Road 
>>> Ste. Anne de Bellevue, Québec 
>>> H9X 3L9, Canada 
>>> (514) 457-6610 Ext. 5888 
>>> michael.dugdale at johnabbott.qc.ca 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> LON-CAPA-admin mailing list
>>> LON-CAPA-admin at mail.lon-capa.org
>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>> 
>>> -- 
>>> Raymond J. Batchelor, PhD.
>>> Department of Chemistry
>>> Simon Fraser University
>>> 
>>> Phone: 778-782-5635
>>> _______________________________________________
>>> 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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> 
> -- 
> Mark Lucas 								email: lucasm at ohiou.edu
> 252D Clippinger Lab						phone: (740)597-2984
> Department of Physics and Astronomy		fax: (740)593-0433
> Ohio University
> Athens, OH 45701
> 
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