ChapterZero

I’ve started working on a modification of the LatexRender WP plugin. My motivation is to increase the ease of certain tasks that I’ve found myself doing often, and add a little more functionality to the current plugin. Here’re a list of the changes I’m planning. Suggestions are welcome.

• Support logically separate classes of LaTeX content: inline, display, and arbitrary TeX/LaTeX. In particular, center displayed content automatically– this should eliminate the need to manually insert div tags to get centered content and the \DisplayStyle command to set the correct display style. The user should be able to use whatever and however many tag names per class he or she feels appropriate.
• Provide a control panel for the user to set plugin options. For the pure math classes, this means font size, color, and face, what packages to include, and auxiliary definitions (e.g. vector notation or common symbols you use repeatedly). For the arbitrary tex content, you should be able to specify complete pre- and postamble sections. Also, there should be an HTML entity replacement table (I keep needing to add new ones directly to latex.php).
• Let the user change the error conditions such as the size of inputted formulas and the resulting image size, and vary them among the classes (e.g. you may want to allow larger images when formed from arbitrary tex than from inline math)
• Provide a mechanism for per post header modifications and a way to reuse these modifications between posts. This would be useful if, for example, you were writing a series of posts on algebraic geometry so needed special notation, but didn’t feel it would be used often enough to warrant adding to the site-wide header.
• Autoconfiguration– the plugin should check that all the necessary tools (latex, ghostscript, imagemagick, etc.) are available and the file permissions are as needed, and offer helpful instructions if needed to resolve these issues.

Wow. That was not fun– I had to rediscover how to do several sysadmin type things, and the whole while I was afraid I’d cause some irrevocable error. There still seems to be a problem with accessing external websites, which was present right from the pristine file-system, so I’m stumped on that one. On the other hand, I got a new plan with increased memory, and since I’m a long time customer (>2 years?) my host generously gifted me with an additional 64Mb, so I’m good on that front. Maybe I have enough to mess around with Ruby on Rails. I also got an additional IP address!

All’s not done yet: for the blog I still have to reinstall plugins, themes, and external files, and probably muck about with .htaccess files to make permalinks work properly. For everywhere else on the site, I can just copy the directory structure directly.

Some time soon, the site’s going wayyy down for a while – hopefully it’ll be back up by Monday, but in the worst case scenario, I plan to have it up by the following Monday.

Apparently my host has not blocked port 80, and one of the tech people tried various approaches which didn’t work:

I have taken a look over you VPS. First thing I noticed is that you are low on free memory:

tangentspace:~# free
             total       used       free     shared    buffers     cached
Mem:         98492      84264      14228          0       8552      47212
-/+ buffers/cache:      28500      69992
Swap:        65528      11452      54076

And this is right away after a reboot. There were processes killed by oom (out-of-memory) killer (sometime in the past).

Your issue is really strange, though. I have installed chkrootkit (which also upgraded your libc6 core libraries) to check if your VPS was not hijacked but nothing solid was found. I still presume that it was somehow hacked (by the way: please consider upgrading your system:
‘apt-get dist-upgrade’ as there is already a new stable branch) because of the strange issue on lynx, wget and (maybe) any other webbrowser installed on your VPS.

I have checked also iptables with:

# iptables -nL

and

# iptables -t nat -nL

but nothing shows up.

I have also installed ‘links’ (another web browser) and that one seems to work correctly, please try it out.

Please try a dist-upgrade as this will basically replace your old files with new ones, and maybe you get rid of this enoying issue.

If you have anymore questions, please get back to us!

Unfortunately, whatever method apt-get uses to retrieve the list of packages from the servers has been affected by this ‘bug’, so I can’t run an upgrade. So, to deal with both the memory problem and web access problems, I’m going to switch VPS plans to one with the next highest amount of memory, and wipe the filesystem. I’ve backed up all the relevant data, so I can painlessly restore the site’s directory structure and database tables. However, I forgot all the mods that needed to be made to apache’s configuration, so I might have to mess around with that for a while. That’s going to be meesssyyyy — I know my domain serving is set up nonstandard, but I don’t recall exactly how — involving trial and error on an epic scale (you know, days of waiting for DNS records to update), most likely. Maybe this time around I’ll manage to do things right (TM).

In trying to figure out why Akismet suddenly broke, I isolated the part of the code that calls akismet.com, and ran that alone. The results showed that instead of contacting akismet.com, the server is trying to contact a search engine looking for akismet.com. So I logged in and tried using lynx and mozilla to pull up a couple of sites, and the same thing happens. I figure my host must have suddenly blocked port 80, so I contacted them and asked what’s up. Hopefully that is the situation, and I can get them to whitelist akismet.com and be back to business as usual. Otherwise I haven’t a clue on how to proceed, other than to pay them to do some sysadmin detective work.

Either way, I’m tired of working with Spam Karma — I have only a fuzzy idea of how it works, and the fact that it’s entirely on a system of rules makes me feel Akismet, which gathers information on what is spam and what is not from many sources and uses this to make its decisions, has to be more competent.

Akismet has crapped out on me lately; consequently today alone I’ve waded through 700+ spam comments in moderation. In retaliation, I’m doing a summer cleaning of the site. I’ve upgraded WP from v2.0.1 to v2.2.1, mostly so I don’t fall so far behind that plugin compatibility is a major issue; along the way I’ve switched to the contentious Garland theme. Maybe someday I’ll get around to customizing a theme to fit my unique needs, but until then I’ll use the best of the prepackaged stuff.

In the course of upgrading, I pretty much reinstalled from scratch, only saving the original Mysql database, so there may be a few missing links to files that I had in the WP directories, and such. I’m going to resolve these as they occur, so if you find something you were looking for is no longer there, just let me know.

Apparently the Now Reading plugin has been broken by the upgrade. Also, I just started using Spam Karma, since Akismet is resisting my attempts at diagnosis.

I’m trying out the Now Reading plugin, which helps you list the books you’re currently reading, planning on reading, or have already read. I won’t be listing any of the math or physics books that I’m currently ‘reading’, since those change from day to day. Instead expect a roster of sci-fi, fantasy, and general fiction and non-fiction (as I try to expand my horizons). I welcome reading suggestions for any thought-provoking, well-crafted books.

I found the problem with LatexRender: somehow, when I was attempting to uninstall unused packages from the server, I deleted gs and imagemagick; my guess is that ‘apt-get prune’ is a lot more powerful than I thought it’d be. So now I have equations back, I’m back!

The site is going to be down for the next week or so, for three reasons: I’m finally doing all those things I was to do this summer, but didn’t; a strange error is occuring with the LaTeXRender system that has rendered all the equations unreadable, and what can I post about, if it doesn’t include equations?; finally, the MySQL server keeps going down, yet again, this time I suspect because I’m running MlDonkey on the server also, and it’s eating up memory.

Later.

I just tried three times to post a comment, and each time it disappeared— didn’t show up in the moderation queue or in the comment list. That explains why I’ve been having a remarkable dearth of spam of late.

I can’t think of anything that might be causing this. My blacklist is clear, and I don’t have any active anti-spamming plugins. So I have another job to do.