Telemarketer: Would you like a free Toronto Sun newspaper subscription for six weeks?
Me: No.
T: How about just a weekend?
M: No.
T: Do you read any other papers?
M: No…
T: Well then, how do you get your news, sir?
M: Online.
T: Do you realize you’re not getting the in-depth coverage?
M: Yes I am.
T: Have a good day sir. *Hangs up*

“News: If you’re not getting the in-depth coverage from the Toronto Sun, you’re doing it wrong.”

Rare as my posts are, Twitter has been siphoning whatever exhibitionist energy I have. You can follow me on Twitter if you’re interested in my day-to-day comments.

Why Twitter? Few years ago, I had an idea for a “one-liner blog” where one would post short one-line thoughts multiple times per day. Few months later, Twitter came along. Although it’s not exactly how I envisioned such a creation, it is useful nonetheless. In day-to-day usage, I get about 30% of my interesting news bits from various people I follow on Twitter. It’s great for getting a live real-life feed of what’s going on with the tubes, conferences, weather, sports, politics, or whatever you happen to be interested in — so long as you follow people who have similar interests as yourself.

Twitter has a lot of unspoken etiquette (tweetiquette) and it’s not for everyone, but I like it. It has a very small commitment threshold (unlike blog posts) and you feel more like part of a community.

I’ll still keep blogging, but I just wanted you to know where I’ve been.

You’ve heard of memcached, haven’t you?

Made by Livejournal to sustain millions of angst-ridden teen diaries, now used by web giants like Slashdot, Digg, Wikipedia, Facebook, Youtube, and countless more. Even this very Wordpress blog supports it.

The same misconception seems to haunt all those unfamiliar with the memcached: it’s some sort of magical layer that sits between your database and your application layer, and somehow it makes things faster. The magic is scary. How would something know what it needs to speed up from the database? It must require all sorts of nasty configuration, all sorts of nasty corner cases to cover?

Admit it. The thought of using memcached terrifies you. Well, I have good news for you: That’s not what memcached is. Are you read for it?

Memcached is a hash table.

No, seriously. It’s that simple. It’s a hash table that sits in memory, that can scale between multiple servers. All you do is launch the memcached daemon on your server with memcachedand you can use it!

“Well obviously that’s not all there is…” you say. It is! As far as the server is concerned, that’s all the configuration it needs.

Now, the client side…

How does the hash table work? It’s just like a dictionary. To save data: you send it a key/value pair, and it saves it. To retrieve data: you send it a key, and it gives you the value. Explicit. Simple. Efficient. It supports a handful of simple operations like set, get, and replace.

Here’s how to use 3 distributed memcached servers to cache a huge query in Python:

import memcache
...
cache = memcache.Client(['192.168.1.100:11211',
                         '192.168.1.101:11211',
                         '192.168.1.102:11211'])
...
def get_post(post_id):
    "Return data associated with post with given post_id"
    result = cache.get(post_id)
    if not result:
        # No cache, perform potentially costly SQL query
        result = model.Post.get_post(post_id)
        # Save result in cache for next time
        cache.set(post_id, result)
    return result

Do you see what they did there?

Yes, it’s not magic. Yes, you have to cache things explicitly. Yes, this is incredibly powerful. Now go. Go make a Slashdotting-proof web service, that’ll show them.

Today, you’ll get to hear about what I’ve been up to! This wont be on the exam.

• After a year and a half stint with Ubuntu, I’m back to my true love Gentoo. That is, with a shiny matte new quad core beast of a machine.
• Bought Rockband for my PS3 couple of weeks ago. Drums are ridiculously hard. Been rocking out. Good fun is being had by all those who dare rock. Can’t wait for Still Alive to be released for free. It shall be a triumph!
• What started out as pretty code is now a bonafide open source Python module: workerpool. People are using it. No, really.
• muxtape.com: A super simple music sharing web app launched last week. Its been enriching my life — doing what Pandora once did. Here’s my muxtape. Be right back, there’s someone at the door.

1. Back up my precious save files: Formatted my external hard drive to FAT32, plugged it into the PS3, went to System Settings > Backup Utility, and hit OK.

   While it’s backing up, I’m reading various Playstation 3 hacking forums, such as ps2dev.org where the first hack to utilize the locked-away GPU in Linux was created. Apparently there’s also hope to use the Playstation Eye as a webcam…

2. Burned the installcd ISO, inserted it into my PS3, hit Install other OS, it did its magic, rebooted, and I was in the Gentoo install CD. Just like that.
3. Plugged in a keyboard into the PS3, created a password, started sshd, and ssh’d in from my desktop and did the rest from the comfort of my fancy chair.
4. Followed the Gentoo Install guide which took about 20 minutes of work, the rest was waiting for things to download, extract, and compile. Meanwhile, I ate pizza and watched the first couple of episodes of Jericho through my PC. Not too bad.
5. Time for the real purpose of this ordeal: Setting up emulators. After much trial and error, I learned that Mednafen is the cream of the crop. After more jumping through hoops, I created the perfect controller configuration that supports two PS3 Sixaxis controllers plugged in USB (bluetooth works too!). You can download it here: mednafen.cfg. Shove it in your ~/.mednafen/ and you’ll be good to go — full screen and all.

   To make your own key bindings, read the nitty gritty in this thread.

Inspired by xkcd.