Recently in MovableType Category

Time to dust the cobwebs off my blog and get it going again.

The iPhone plugin for MT is pretty sweet - using it now for this post.

Movable Type's PublishQueue has some memory leakage, and running in daemon mode (for quicker response to rebuilds) highlights this problem.

So the solution (where solution = not particularly pretty workaround) is to run PQ under daemontools as per this writeup by Byrne Reese. This sets up a monitor which constantly scans for the PQ job and restarts it if it's not there.

Then create a cronjob that kills PQ every hour or so, using pkill

*/15 * * * * pkill -SIGINT run-periodic 

So, in this example, the cronjob runs pkill every 15 minutes and kills any processes that contain 'run-periodic'  in their name (run-periodic-tasks is the perl script that runs the PublishQueue workers).

The svscan process (part of the daemontools suite) notices instantly (within milliseconds) that the PQ task isn't running, and starts it up and memory is back to normal.

Now, this obviously isn't ideal, but the 6A guys (and some of the more Perl aware parts members (!) of the community) are well aware of the problem, and are looking at how to fix the leaky bits, as well as make the whole thing run better and faster. In the meantime, this is working well for me.

[Update - 6A have acknowledged the memory leaks issue in the latest MT 4.1 release notes and have advised that PublishQueue not be run in daemon mode, or with FastCGI - both of which are fairly essential. My workaround is even more valid now.

Also note the addition of the SIGINT signal to the pkill command - this is a less forceful shutdown and was recommended to me in the #movabletype IRC channel]

I've just moved this site from Wordpress over to the latest build of Movable Type 4.1, using the new Universal Templates.

I've also decided to retire my old blog - scalefree, and have imported all the content across to here - I'll be redirecting everything from scalefree shortly.

MT4.1 really rocks - and the new template set mechanism will allow for Wordpress-like easy styling - and enabled me to get this complete site up and running in a couple of hours.

Contact me if you want more information, or if you'd like a site like this for yourself !

Movable Type relies on a number of libraries and additional pieces of software to perform certain functions - especially where images are concerned. Thumbnailing and captcha both rely on ImageMagick to perform various feats of graphic trickery.

However, getting ImageMagick playing nicely with Perl and Movable Type is not always straightforward. If you're on a good host, then this work may already have been done for you (leave a comment if you're with a host that has this sorted out), but even good hosts don't always get this right, and if you're on a dedicated server, this is probably something you'll have to do yourself - as I've just done with my MediaTemple (dv) server.

I'm documenting the steps I took to get this working - hopefully it will be useful to someone else (and me in the future, the next time I have to do this). Please note that the steps require that you have root access, and are for dedicated servers (or dedicated virtual servers), and you need to be running Linux - I'm using CentOS, but I'm pretty sure this works for any distro.

Ok - so first up, browse to mt-check.cgi and see whether Image::Magick is already there. It's in the same directory as mt.cgi, so just replace with mt-check.cgi in your normal URL for MT.

If you're lucky, and it's already there, then you're done. Congrats, and enjoy !

If you're not lucky, then you'll see somethinng like "Image::Magick. Your server does not have Image::Magick installed...". Time to roll up your sleeves.

• Get the latest version of ImageMagick (6.3.6 at time of writing). You can get it from here (ftp link to imagemagick.tar.gz). If you're rabidly anti-ftp, then go to this page and follow links until you get what you want.
• Ungzip and untar it (tar -zxvf ImageMagick.tar.gz), and change to the source directory (cd ImageMagick-6.3.6).
• Build imagemagick

./configure
make
make install

• This will build and install the main ImageMagick binaries and libraries
• Now we've got to build PerlMagick - the Perl interface to ImageMagick (which is what Movable Type uses to communicate with ImageMagick). The PerlMagick library should be below the ImageMagick folder you're in now.

cd PerlMagick
Perl Makefile.PL
make
make install

• In an ideal world, we'd be done now. Unfortunately, it seems as if there are often some problems with where ImageMagick puts its libraries such that PerlMagick can't find them.
• Test by running mt-check.cgi again. If it's working, congrats again - if not, read on.
• Take a look at the error log (probably something like /var/log/httpd/error.log) and look for lines mentioning ImageMagick - chances are you might see something like this

[error] Can't load '/usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi/auto/Image/Magick/Magick.so' for module Image::Magick: libMagick.so.10: cannot open shared object file: No such file or directory at /usr/lib/perl5/5.8.5/i386-linux-thread-multi/DynaLoader.pm line 230.\n at /var/www/vhosts/xxx.xxx.com/httpdocs/test/perl/image_test.pl line 9\nCompilation failed in require at /var/www/vhosts/xxx.xxx.com/httpdocs/test

• Basically this means that PerlMagick can't find the ImageMagick libraries it needs. To resolve this issue:
  • Edit /etc/ld.so.conf and add /usr/local/lib below the last line.
  • Run ldconfig
  • You should now be done ! check by running mt-check.cgi again or by running this perl -MImage::Magick -e 1

 

• If it's still not working, you can try this kludgier way:
  • Check what libraries ImageMagic.so needs by running the following (you may need to change the path to match what you're seeing in your own error.log file)

    ldd /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi/auto/Image/Magick/Magick.so

  • This might give you something like this:

    libMagick.so.10 => (missing)
libWand.so.10 => (missing)
libc.so.6 => /lib/tls/libc.so.6 (0xb7ca4000)
libtiff.so.3 => /usr/lib/libtiff.so.3 (0xb7c57000)
libjpeg.so.62 => /usr/lib/libjpeg.so.62 (0xb7c39000)
libbz2.so.1 => /usr/lib/libbz2.so.1 (0xb7c28000)
libz.so.1 => /usr/lib/libz.so.1 (0xb7c18000)
libm.so.6 => /lib/tls/libm.so.6 (0xb7bf4000)
libpthread.so.0 => /lib/tls/libpthread.so.0 (0xb7be2000)
libdl.so.2 => /lib/libdl.so.2 (0xb7bde000)
/lib/ld-linux.so.2 (0xb7fea000)

  • OK - so there are 2 libraries - libMagick.so.10 and libWand.so.10 that can't be found. The chances are that PerlMagick is expecting to find these libraries in /usr/lib, instead of /usr/local/lib. So let's put them there:

    ln -s /usr/local/lib/libMagick.so.10 /usr/lib/libMagick.so.10
ln -s /usr/local/lib/libWand.so.10  /usr/lib/libWand.so.10

  • And that should be it. Run mt-check.cgi again, and you should now see that MT finally agrees that ImageMagick has been installed.

[Updated with a better initial method - editing /ld.so.conf which removes the need for the symlinks]

Good luck !!