two interesting posts arrived on the memcached list which might be interesting to performance people.

The first was a comparison of The fastest lanugage binding on which ‘P’ language performed better. To make a note the PHP version actually uses libmemcache a ‘C’ library which goes a bit of the way to explain the wild disparity in speeds.

The 2nd more interesting one (to me) was the discussion of how Digg switched from using mysql to memcached with v3 of their new interface to handle storing sessions, due to a hardware crash on their mysql server.

others mentioned using InnoDB for this instead of MyISAM, with the biggest issue …

are you a committer or a member of a large OSS project?

do you participate in any other large open source project?

I’m trying to get a understanding of how all the different major oss projects are being cross pollinated by having people participating in different projects.

feel free to comment, or mail me directly at ian at holsman.net

Thanks!

continuing the recent thread about contenttypes in django I thought I would talk about a feature which got added in the magic removal branch, which doesn’t have as much attention as I think it deserves.

signals and the dispatcher.

signals are way of telling the rest of the world that something happened. If you are interested you simply listen for it (connect in django speak).

take for example my tagging application currently in use on zyons. one of it’s features is that it let’s users store their own tags.

One of the performance improvements I added to this was the creation of a ‘summary’ tag which aggregates which the …

I’m sure most would agree when one does a programming mistake they are a lot of times trivial mistakes. However when one stares at the code for long periods of time we seem to go blind and then in the process of frustration loose all logically thinking as to what could be causing the problem. Here is one such problem with arrays.

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There is many ways to populate vales into a HTML select element. Here is one example I’ve come up with.

PHP Code Example

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      <select size="1" name="szFooBar[]" multiple="multiple">
< ?php
$i=0;
while($obResults = mysql_fetch_row($saResults))
{
    if ($_POST['szFooBar'] == $obResults[0])
    { $szSelectedValue[$i] = " selected=\"selected\""; }
    else { $szSelectedValue[$i] = ""; }
 
    printf("<option value=\"%s\"%s>%s\n",$obResults[0], $szSelectedValue[$i], $obResults[1]);
    $i++;
}
?>                                                   
</select>

…

Vani and I both started using "Life Balance":http://www.llamagraphics.com/LB/LifeBalanceTop.html for our todo lists in the last week or two. It's great so far.

One of the items I added was a occasionally recurring "File a bug report" task.

Writing a "good bug report":http://www.chiark.greenend.org.uk/~sgtatham/bugs.html is a relatively quick and easy way to help the authors and maintainers of the software you use make it better.

I was working a bit with "Xen":http://www.cl.cam.ac.uk/Research/SRG/netos/xen/ on Fedora Core 5 some days ago and found out that the default scripts don't deal nicely with anything but the most basic net configuration. "Hello bugzilla":https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=193322.

MySQL is one of the nicest projects to file bug reports for, because they are very nice about "following up":http://bugs.mysql.com/bug.php?id=19498 and actually …

Vani and I both started using "Life Balance":http://www.llamagraphics.com/LB/LifeBalanceTop.html for our todo lists in the last week or two. It's great so far.

One of the items I added was a occasionally recurring "File a bug report" task.

Writing a "good bug report":http://www.chiark.greenend.org.uk/~sgtatham/bugs.html is a relatively quick and easy way to help the authors and maintainers of the software you use make it better.

I was working a bit with "Xen":http://www.cl.cam.ac.uk/Research/SRG/netos/xen/ on Fedora Core 5 some days ago and found out that the default scripts don't deal nicely with anything but the most basic net configuration. "Hello bugzilla":https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=193322.

MySQL is one of the nicest projects to file bug reports for, because they are very nice about "following up":http://bugs.mysql.com/bug.php?id=19498 and actually …

If you have been reading my previous entries the answer you will think is ‘not bloody well’.

After about 3 days of tuning we doubled the throughput, and got a much nicer picture, outperforming a x86-64 machine by 2.5 times in one case.

Thanks to Luojia Chen (Jenny) from Sun, Peter Zaitsev from Mysql, and Colm MacCárthaigh & Mads Toftum from the ASF.

oh.. the benchmark.. I nearly forgot ;-)

(Oh people..please link to the blog entry, and not the paper itself.. Thanks)

update: people were having issues downloading the PDF. so I placed a mirror of it here

ok.. now this is getting stranger.

I have 2 windows open, in one I get

$ mysqlslap --use-threads -psunfire -c 90 -i 500
Benchmark
        Average number of seconds to run all queries: 2.180 seconds
        Minimum number of seconds to run all queries: 0.779 seconds
        Maximum number of seconds to run all queries: 4.497 seconds
        Number of clients running queries: 90
        Average number of queries per client: 0

and in the other i get

$ mysqlslap --use-threads -psunfire -c 90 -i 500
Benchmark
        Average number of seconds to run all queries: 0.012 seconds
        Minimum number of seconds to run all queries: 0.002 seconds
        Maximum number of seconds to run all queries: 0.015 seconds
        Number of clients running queries: 90
        Average number of queries per client: 0

same machine, same user-id, same binary. the only difference is that mysql started in the ‘fast’ window.

Recently I've been working on a large-ish project where all of the UI is written in Javascript. That, in itself, is great. The environments (the browsers) are crappy crappy for development though. Sure, there are Firefox extensions etc etc to help, but it's Just Not Great. Javascript = Great. Ajax = Yay. Browsers = Bah.

Over the weekend I spent all sorts of time getting a simple Rails application running with Apache and mod_fcgid. When I gave up and tried making it work with lighttpd I got server error galore. Yay. What was wrong? My fastcgi? The fcgi Ruby extension? My ruby installation is in /pkg/packages/ruby-1.8.4 or some such and the gem tool couldn't find its own libraries after being installed there. Maybe something similar for something else? I have no idea, I got no error messages anywhere. Ruby = Great. Rails = Very nice[1]. Ruby Gems = It sure is no CPAN.pm. FastCGI/lighttpd/etc = Loosely coupled? No mister, you have some way to …