We have been struggling with this for a few weeks now and wondering if anyone else is in the same boat? Last year we enabled and have been successfully using the unoconv document converter to convert word docs to PDF for Moodle Assignment Annotation PDF feature. Recently we've hit a major issue where some documents fail to convert and are "stuck" which in turn hold up the queue in the \assignfeedback_editpdf\task\convert_submissions (Annotate PDF) scheduled task belonging to the mdl_assignfeedback_editpdf_queue.
Any document stuck in the queue also crashes the user interface where you either get a white screen of death or the page becomes unresponsive after a while.
Our external hosts have managed to minimise the issue by having a compatible LibreOffice version with unoconv (stated below) which withstands most conversions but you still get an odd one here and there which holds up the whole queue.
Potential work-around:
- Going forward we plan to keep Document conversions (a new feature added to Moodle 3.4) open turned on BUT make PDF the default submission type which would help minimise the problem but we are really not pleased with this as academic really enjoy the features of word documents being automatically converted to PDF on the fly for them to easily annotate all on one single grading page.
- An automated script that kills the last item stuck in the queue so the rest of the items can move on to being converted. The only problem here is how to you determine if something is definitely “stuck”? Do you keep a record of the last successfully converted item and compare it with the current one determining a threshold for how long an item has been in the queue ( for example more than 30 mins ) and hence qualifies as “stuck” ?
We do appreciate that none of the solutions are full-proof and hence the best way would be if someone could confirm that unoconv is the best way forward and maybe a work around on how to deal with documents that fail to convert.
For now, we are keeping a record of every offended submission in an excel sheet to collect evidence on why the documents might fail to convert.
Anyone else in a similar situation to us and are using any clever automated scripts to combat or even fix the conversions?
Also, is one else using a different document converter mechanism to unoconv? We do know of Microsoft Office converter and Google Drive converter but we are not so sure with the latter one due to the safe harbour agreement.
Software specifications:
Moodle 3.1 with mySQL
LibreOffice 5.4.6.2
Unoconv 0.8.2 ( using a listener)
Happy to provide any more server info if required.
Related forum posts:
https://moodle.org/mod/forum/discuss.php?d=350320
https://moodle.org/mod/forum/discuss.php?d=347320
Thanks a lot ,
Hittesh Ahuja