Hi everyone, I've been trying to troubleshoot this issue with our environment for a while but have not had much luck. I have also inherited this Moodle installation so do not yet know all the ins and outs and I was hoping someone could point me in the right troubleshooting direction.
The basic problem is that one of our courses has very slow loading times for it's SCORM module based units. This course has been copied a number of times and the previous copies of it do not have any of the performance issues. The course is already running so re-creating it again to try to resolve the issue is a difficult proposition. All of the other components of the course run normally also, such as quizes, etc.
I've been doing troubleshooting and it does not seem to be related to any underlying server wide or db wide performance issues, as other courses are normal speed while this course is not. I do not think it's the SCORM package/module itself, as that same module with the exact same zip package file runs fine on other courses, with the exact same options.
With Fiddler I've managed to trace the slow down to pluginfile.php specifically, for example the HTTP GET request: /pluginfile.php/18294/mod_scorm/content/1/images/tableofcontents.png
takes over 11 seconds from the time the server got the request to the time it sends it's response. Since it has to run this for each file in the SCORM package (dozens of files), the whole things takes over a minute or several minutes to load.
Something specifically about pluginfile.php with a few specific DB identifiers seems to be slow. I have a few demo samples, don't worry about logging in, you can see the delay anyways.
This first link, from a scorm module in a previous instance of the course runs quickly, returning in under 1 second.
This second link, from a scorm module in the current slow instance of the course, takes over 4 seconds to return.
Both of these files don't actually exist on the server, so the underlying file system should return them at the same speed, and if there was a hardware performance issue, it should return them at the same speed also.
Any tips on narrowing this down further?
Dedicated Solaris web server running apache, seperate MySQL server. We don't handle huge numbers of users, on average about 10-20 concurrent users but our courses are rather large and interactive in terms of video and audio.
In addition, the problem seems to be interrmittent at times. Our users report that at most times it is slow, but ocassionaly when they switch browsers or try it at another time it speeds up.