geek stuff - 15

Yesterday Lig and me put out the third edition of the PHPCommunity Gazette. It has some very nice articles, do check it out. If you want to write an article for it, drop us a mail, but remember that we would not be able to pay you anything, except a nice "thank you" note - it is a voluntary effort .

Some weeks back, I was talking with my manager about AI and how it is such a bogus field. My manager replied that in a few years we will see applications that use AI in our daily life. However, I was quite skeptical - and I refused to agree to this. He then gave an overview of neural net and how they can learn to solve the problems. Here I pointed out that Bayesian filters can also be considered a form of AI, as they can learn from their previous data and they can make decisions, but Bayesian filtering is mathematics and not AI. At this he replied that most of AI is mathematics and only some part of it is hocus-pocus and hand waving.

This brings me what I have been thinking for a long time.Joel write

A very senior Microsoft developer who moved to Google told me that Google works and thinks at a higher level of abstraction than Microsoft. "Google uses Bayesian filtering the way Microsoft uses the if statement," he said.

. I had always suspected this and had also felt that this was the way to go. A few months back, we had a presentation by a researcher (not a Yahoo! employee), who was working on extraction and summarization of documents. He had a formula that he was applying on the sentences of the documents to find the weight of the whole sentence and then finally if the weight of the sentence was above some limit, it showed up in the summary. I was skeptical about this approach - my belief is that the Bayesian approach can be used to classify documents. Luckily, there is a project that seems to provide a framework on which things can be built further.

By default, MySQL's datadir is placed in the /var/lib/mysql directory. However, if you are planning on using MySQL tables to store a lot of data and your /var partition is small, it might cause you problem at a later stage. In such a scenario, it is better to move the MySQL's datadir to another partition (like /home.

The steps are

1. Stop your mysql server before starting this operation
2. Create the directories that will be new datadir
3. chown the directory to the mysql:mysql user
4. copy the files from the old datadir to the new location. However, make sure that the files named ib_arch_log_0000000000, ib_logfile0 etc. are not copied to the newer location.
5. Make sure that the files and directories are owned by mysql user
6. Make changes in the my.cnf to point the new datadir.
7. Restart the MySQL database
8. You might need to do varying degree of troubleshooting to get the server working if there is some problem
9. Create a new database and verify that the files for this database are getting created in the new datadir
10. After the server is running for a few days properly, get rid of the old data.
11. Sleep

I tested these steps on MySQL 4.0.24 and all my tables were MyISAM type.

Fuck cisco for this. Here are the notes from Lynn's presentation.. Unsurprisingly, a small list of mirrors for Lynn's presentation is here.

from Tao of security blog, I came across this

One of the details that emerged from Curt's monitoring of the Invita Security network involved a password used by Alexey Ivanov. When accessing one of his drop sites, Alexey's FTP password was www.pidor.com (Internet Archive available). Think of what an unwary analyst might do with that information. Only someone who is monitoring Alexey's actions might know about www.pidor.com. Say that unwary analyst decides to visit www.pidor.com to learn more about the site. If Alexey or a friend is monitoring Web accesses to www.pidor.com, they could learn that they are being monitored. This case demonstrates how important it is for analysts to not "touch" remote or foreign sites involved in intrusions. You may tip your hand to the attacker and ruin an investigation or recovery effort.

Vendorwear - a piece of clothing with a vendor's logo on it. Usually it is a t-shirt.

I have moved my blogging software from Wordpress to Serendipity. It was able to import the entries from Wordpress without any problem. I needed to create 3 additional files to make the transition complete i.e. wp-atom.php, wp-rss.php, wp-rss2.php . These were needed so that people who were using the rss feeds from the Wordpress did not have to change their feeds again.

These files do nothing more than redirecting the users to the new feed url. For example, the content of the file wp-rss2.php is just

<?php
// For redirecting users who are lost 
header("Location: http://rajshekhar.net/blog/feeds/index.rss2");
?>

Beyond this customization, I did not have to do any more labor to migrate to Serendipity