March 2011

The whole point of a blog is to be able to write what I want, isn’t it? Without the need to be coherent. Intelligent. Useful. I read somewhere, in a top 10 list of advice to programmers – to avoid constipation. It’s actually good advice. It gives you a headache for the rest of the day. That piece of code is really not worth it, trust me. But then, when you have a headache, there isn’t anything quite as beautiful and relaxing as code. Or good documentation. Like node.js docs, for example. ...

Sometimes, school marks are moderated. That is, the actual marks are adjusted to better reflect students' performances. For example, if an exam is very easy compared to another, you may want to scale down the marks on the easy exam to make it comparable. I was testing out the impact of moderation. In this video, I'll try and walk through the impact, visually, of using a simple scaling formula. BTW, this set of videos is intended for a very specific audience. You are not expected to understand this. ...

Yesterday, I wrote about node.js being fast. Here are some numbers. I ran Apache Benchmark on the simplest Hello World program possible, testing 10,000 requests with 100 concurrent connections (ab -n 10000 -c 100). These are on my Dell E5400, with lots of application running, so take them with a pinch of salt. PHP5 on Apache 2.2.6 <?php echo “Hello world” ?> 1,550/sec Base case. But this isn’t too bad Tornado/Python See Tornadoweb example 1,900/sec Over 20% faster Static HTML on Apache 2.2.6 Hello world 2,250/sec Another 20% faster Static HTML on nginx 0.9.0 Hello world 2,400/sec 6% faster node.js 0.4.1 See nodejs.org example 2,500/sec Faster than a static file on nginx! I was definitely NOT expecting this result… but it looks like serving a static file with node.js could be faster than nginx. This might explain why Markup.io is exposing node.js directly, without an nginx or varnish proxy. ...

I’ve moved from Python to Javascript on the server side – specifically, Tornado to Node.js. Three years ago, I moved from Perl to Python because I got free hosting at AppEngine. Python’s a cleaner language, but that was not enough to make me move. Free hosting was. Initially, my apps were on AppEngine, but that wouldn’t work for corporate apps, so I tried Django. IMHO, Django’s too bulky, has too much “magic”, and templates are restrictive. Then I tried Tornado: small; independent modules; easy to learn. I used it for almost 2 years. ...

I haven’t found an open or reliable database providing the geo-location of Indian PIN codes. That’s a bother if you’re creating geographic mash-ups. The closest were commercial sources: a PIN code directory from the Postal Training Centre for Rs. 2,000, which probably just contains a list of PIN codes, and a PIN code map from MapMyIndia for Rs. 1,00,000, whose quality I’m not sure of. (I spoke to one of their sales representatives who mentioned that the data was gathered via companies such as Coca Cola, using their local distribution knowledge, perhaps GPSs.) Crowd-sourcing this might help. Here’s a site where you can map the location of any PIN code you know: ...