• Web serving environment, including a Python runtime environment + Django framework. Competes with Amazon’s Elastic Computing Cloud.
• Persistent storage powered by Google BigTable and Google FS, supporting its own query language and transactions using optimistic locking (what?! no MVCC?) Competes with Amazon’s Simple Storage Service and SimpleDB.
• API for authenticate Google users, sending emails, fetching URLs, etc.

Looks much more restrictive than Amazon’s EC2 where you get your own Xen VPS. However Google also gives you 500MB storage, 200M megacycles of CPU time/day and 10GB data transfer/day for free, which is enough for any startup to prototype their next killer app. Developing for a sandbox is never fun though, but the SDK provides an emulated environment so you can do your development locally before uploading to Google App Engine.

Biggest winner? I think it is Python. Hopefully we will see more Python-based web applications this year.

Update: TechCrunch has already coded and deployed their first HotOrNot-type application on Google App Engine — and it took the RoR guy only 4 hours to sign up, figure out Python, code up the site and deploy. Too bad that it’s already too popular and ran out the quota.

Update 2: Interesting response from Joyent, which has already made its way into providing utility computing via its Accelerator/Solaris Container products. Basically what Joyent is saying — no root, not open! Obviously they are still stuck in the mindset of doing all the scaling themselves which is only possible when you have the admin access to the running instances. It is great when you have root — sometimes — when you want to tinker with the setup yourself. What Google is saying here is, just worry about coding around the framework, and they’ll do the scalability for you. Having “root” will only blow a hole in your foot in this case.

Permalink Redirect 0.8.4

I have updated Permalink Redirect plugin to 0.8.4. The main functionality of this plugin has been replaced by WordPress’ redirect_canonical() function since WP 2.3, but somehow some people are still using this plugin for its remaining functions (permalink structure changes, arbitrary path redirect, etc). 0.8.4 fixes an issue with arbitrary path redirect when the old path is now producing 404. It has also overwritten the wp_redirect function (taken from WP 2.5) so 301 redirect works properly on Lighty/Nginx setups.

ESVPopup 1.4

Don’t you love browser incompatibility?! While everyone is trying to crack Acid3, I am still trying to figure out why event.clientX on Safari is different from all the other browsers.

Anyway. ESVPopup 1.4 should work with Safari 3.0.x now.

Btw, this blog has also been upgraded to WordPress 2.5. Nice new dashboard and so far everything works. Finger crossed.

During interview for developers, we usually asked our candidates their preferred development methodology and whether they have heard of agile programming, although we are not structurally practising any of these unstructural programming methodology anyway (just that they are buzzwords these days and nothing more). Seriously, in a small team with more work than everyone can possibly handle, with customers wanting immediate feedback continuously and a lot of things have to be done adhoc-ly — let’s just call it “agile”…

Remote attackers might be able to exploit these issues in PHP applications making use of the affected functions, potentially resulting in the execution of arbitrary code, Denial of Service, execution of scripted contents in the context of the affected site, security bypass or information leak.

On the right hand side, we have HTTP_RAW_POST_DATA bug in PHP 5.2.2.

So $GLOBALS['HTTP_RAW_POST_DATA'] is not set. The PEAR::XML_RPC package actually uses $HTTP_RAW_POST_DATA on the receiving end, but that doesn’t appear to be set either. And the always_populate_raw_post_data option in php.ini doesn’t make a difference.

That means, any PHP code that assumes the existence of $HTTP_RAW_POST_DATA will simply fail as that variable is no longer populated. With all the API, web services, etc, there are actually many applications that use raw post data, which could be XML, JSON, or any other package formats. Pingbacks simply won’t work in WordPress, although WP 2.2 has a work around on this PHP 5.2.2 bug.

So I basically upgraded all my servers to PHP 5.2.2 early last week. found many web services code I wrote were broken, and was forced to revert back to vulnerable PHP 5.2.1. The bug has been fixed and there’s a work around, but I would rather wait for 5.2.3 to hit the street, which I hope to be sooner than later.

To be fair, it sounds like most of Twitter’s problems are database problems, so maybe it doesn’t matter what language they use”

Even Alex stated it clearly in the Twitter interview that database has been the bottleneck, just like most share-nothing web development platform that was designed to be highly scalable in the first place! Ruby is slow. Python is a tad better, but in a heavily IO bounded web-based application, both will be more than fast enough. How to scale the database? It is not trivial and very domain specific, and that is what Alex is complaining about.