Linus on Evolution

Here is a great rant from Linus Torvalds back in 2002 on biological and software evolution.
... from a thread on LKML, summarized here: http://kerneltrap.org/node/11

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You know what the most complex piece of engineering known to man in the whole solar system is?

Guess what - it's not Linux, it's not Solaris, and it's not your car.

It's you. And me.

And think about how you and me actually came about - not through any complex design.

Right. "sheer luck".

Well, sheer luck, AND:

• free availability and _crosspollination_ through sharing of "source code", although biologists call it DNA.
• a rather unforgiving user environment, that happily replaces bad versions of us with better working versions and thus culls the herd (biologists often call this "survival of the fittest")
• massive undirected parallel development ("trial and error")

I'm deadly serious: we humans have _never_ been able to replicate something more complicated than what we ourselves are, yet natural selection did it without even thinking.

Don't underestimate the power of survival of the fittest.

And don't EVER make the mistake that you can design something better than what you get from ruthless massively parallel trial-and-error with a feedback cycle. That's giving your intelligence _much_ too much credit.

Linus

Python - URL Timer - Web Monitor Utility

In a previous post, I showed how to insert timers between steps in an http request to do some basic profiling. Peter Bengtsson contacted me with some enhancements to the original code. I took his enhancements and added some more of my own to create a neat little web monitoring utility.

It uses Python's httplib to send a GET requests at regular intervals to a URL and adds some timing instrumentation between each step of the request/response. Results are printed to the console.

get it here:
http://code.google.com/p/corey-projects/source/browse/trunk/python2/url_timer.py

to use, give it a site and interval:

> python url_timer.py www.goldb.org 5

... or an https/ssl url and an interval:

> python url_timer.py https://ssl.sonic.net/ 5

sample output:

>python url_timer.py www.goldb.org 5
request sent         response received    content transferred  size
------------         -----------------    -------------------  ----
0.0040 (0.0040)      0.2830 (0.2830)      0.2846 (0.2846)      9810 bytes (0.010 MB total)
0.0009 (0.0024)      0.2790 (0.2810)      0.2803 (0.2825)      9810 bytes (0.020 MB total)
0.0009 (0.0019)      0.2841 (0.2821)      0.2854 (0.2834)      9810 bytes (0.029 MB total)
0.0010 (0.0017)      0.2775 (0.2809)      0.2789 (0.2823)      9810 bytes (0.039 MB total)
0.0008 (0.0015)      0.2794 (0.2806)      0.2820 (0.2822)      9810 bytes (0.049 MB total)
0.0009 (0.0014)      0.2845 (0.2813)      0.2859 (0.2828)      9810 bytes (0.059 MB total)
0.0010 (0.0013)      0.2796 (0.2810)      0.2809 (0.2826)      9810 bytes (0.069 MB total)
0.0009 (0.0013)      0.2798 (0.2809)      0.2808 (0.2823)      9810 bytes (0.078 MB total)
0.0009 (0.0012)      0.2791 (0.2807)      0.2803 (0.2821)      9810 bytes (0.088 MB total)
...

Automated Web/HTTP Profiler with Selenium-RC and Python

A small new open source project I am working on:

Selenium-profiler is a web/http profiler built with Selenium-RC and Python. It profiles page load time and network traffic for a web page. The profiler uses Selenium-RC to automate site navigation (via browser), proxy traffic, and sniff the proxy for network traffic stats as requests pass through during a page load.

It is useful to answer questions like:

• how many http requests does that page make?
• how fast are the http responses coming back?
• which http status codes are returned?
• how many of each object type are requested?
• what is the total page load time?

Get it here:
http://selenium-profiler.googlecode.com/

Sample Output:

--------------------------------
results for http://www.google.com/

content size: 38.06 kb

http requests: 9
status 200: 6
status 204: 1
status 403: 2

profiler timing:
2.063 secs (page load)
2.047 secs (network: end last request)
0.111 secs (network: end first request)

file extensions: (count, size)
gif: 1, 8.558 kb
ico: 2, 2.488 kb
js: 2, 18.046 kb
png: 1, 5.401 kb
unknown: 3, 3.567 kb

http timing detail:
403, GET, /favicon.ico, 111 ms
200, GET, /newkey, 738 ms
200, GET, /, 332 ms
403, GET, /favicon.ico, 3 ms
200, GET, /logo.gif, 255 ms
200, GET, /d9n_Nh4I09g.js, 411 ms
200, GET, /2cca7b2e99206b9c.js, 65 ms
204, GET, /generate_204, 88 ms
200, GET, /nav_logo7.png, 49 ms