Xarg blog Archive

An article on tuning queries by munging through the postgres server logs.

veryone wants their database-backed web application to run faster on the same hardware - if a software tweak can postpone a hardware upgrade for a year, it's usually well worth it. One way to improve performance is to examine how the application is interacting with the database, and see if there is anything that we can do to speed things up. We will take a look at a handy script that can examine PostgreSQL logs and let you know what queries are getting run the most.

I wanted to try to figure out why AOLServer gets so large when generating pages with a lot of data (when the CVS browser generates a large page the AOLServer binary can grow by 100MB or so -- not a great thing to have happen). Anyway, I fired up GDB and was trying to figure out what was going on and had no success at all. I could not even set a breakpoint...

It turns out that on gentoo (and some others, like Mandrake 9), libpthread is stripped which means GDB can't do anything useful when debugging threaded programs.

If you see

/lib/libpthread-0.10.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), stripped

or get the error

Program received signal SIG32, Real-time event 32.
0x40163834 in pthread_getconcurrency () from /lib/libpthread.so.0

when trying to debug a threaded program, then you will need to get an unstripped version of libpthread, or rebuild it on gentoo with

FEATURES="nostrip" emerge glibc

Interesting articles on open source in the ACM Queue magazine....

In our first open source theme issue last year (ACM Queue 1(5), July-August 2003), we focused on business issues such as using open source software as a basis for a commercial product. We knew that this was an important topic, but predicted that many of our readers might find it boring. We were wrong. That issue remains among the most responded-to issues of Queue to date. So with that response, we are revisiting the open source theme.

After several years of running KDE I realized I don't actually use anything from KDE (besides konsole) and decided it was time to try some other window managers. I am using windowmaker now and I like it so far. I like workspaces and I like the dock but I can't figure out how to get click to raise working without doing alt-right click in the active window (I liked the kde behavior of simply clicking on the window to raise it).

I had to unbind a bunch of things that conflicted with my emacs key bindings.

I have not figured out how to get it to save my descktop but given that I logout once every couple months I may not bother.

I upgraded to OpenACS 5.1 and moved the server off of our overloaded shared machine (although it's still somewhere in Texas). Upgrading was not as bad as I thought it might be although there are a bunch of little things still broken.

I changed my dns entry as well so that may take a day or two to propigate (which hopefully won't bork my email as well, since before I did not have an MX record for xarg.net).

I am always entertained when I find the consequence of spell checking without corresponding proofreading in books or in the newspaper. Today's online version of a Times Op-Ed piece was a pretty funny example:

For some years now, the Energy Department has been hoping to separate its wastes into two streams, reserving deep burial for only the part with high radioactivity. In the case of the South Carolina site, the department is prepared to pump most of the waste out of the tanks for disposal through deep burial. But it wants to leave a hard-to-remove residue of sludge in the tanks and bury it under grout.

Maybe it's just me but I find it hard to imagine that grout is the ideal encasement material for high level nuclear waste...