I have written a couple of posts about disappearing images -- links to those
posts are at the bottom of this email.
The wiki I am running:
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Version info (
http://librepathology.org/wiki/index.php/Special:Version ):
MediaWiki 1.23.5
PHP 5.4.4-14+deb7u14 (apache2handler)
MySQL 5.5.38-0+wheezy1
Lua 5.1.5
$ apt-cache show imagemagick
Package: imagemagick
Version: 8:6.7.7.10-5+deb7u3
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The symptoms:
1. Occasionally, the images the wiki pulled from the WikiCommons
(via "InstantCommons") are gone. Pages with images are left with
broken links to the files (e.g. "File:Name_of_image") and a 'Category'
(automatically)
appears at the bottom of the pages (? "Pages with broken links").
When the problem is present, the image pages created when the files
were copied from the InstantCommons (e.g. "File:Name_of_image") do not
exist.
2. The problem does not happen with an image file (
Atypical_ductal_hyperplasia_-_very_high_mag.jpg ) that is local to the
wiki itself, i.e. an image not pulled from the InstantCommons.
3. A server re-boot resolves the issue.
4. The thumbnailing continues to work for the image local to the wiki.
librepathology.org/wiki/thumb.php?f=Atypical_ductal_hyperplasia_-_very_high…
5. I started caching files on the server for performance reasons. The
cached version of the pages display fine, i.e. anonymous (not logged
in users) see
the images (in the cached files).
The logged in users (when the problem is present) do not see the
(InstantCommons) images.
6. The memory status of the server (when the problem is present) seems to be
fine. Several times when the problem is present physical memory was still
available according to the command 'top'.
7. I see no obvious association with server load.
Things I have tried:
1. Fresh install of 'MediaWiki'.
2. 'diff' comparison between the active (installed) mediawiki and a
fresh download of mediawiki. (No significant differences found.)
2. Upgrading the server's RAM 1 GB to 2 GB
3. Ran 'debsums' (to look for corrupt files) php/apache2/mysql/operating
system files
4. Looked for bug report in the LAMP stack (Debian GNU/Linux).
5. Increased "memory_limit" variable in "php.ini"
(/etc/php5/apache2/php.ini)
to '256M' from '128M'.
6. Increased '$wgMaxShellMemory' to '512000'.
(I wonder if this is making the loading of the pages more sluggish.)
The problem started in late August and I cannot temporally associate
it with any particular change. I rolled back a number of changes I
made in August and the intermittent problem reoccurred.
The wiki is on a virtual server... I can access all the logs.
I am happy to take suggestions on where to look... or tests I could do.
Unfortunately, I cannot reproduce the problem. I don't really have an
idea what triggers it.
Some of the previous messages --
https://lists.wikimedia.org/pipermail/mediawiki-l/2014-September/043292.html
https://lists.wikimedia.org/pipermail/mediawiki-l/2014-September/043294.html
https://lists.wikimedia.org/pipermail/mediawiki-l/2014-September/043340.html
Thanks,
Michael
