A Java Servlet for Thrift

I've been playing around with Thrift (the new version that came out a few days ago), mainly to see how it might be used as a serialization mechanism in Hadoop, but also because the RPC looks useful. It doesn't come with a Java HTTP server transport, so I whipped up a servlet to make it easy. Exposing a service is then as simple as subclassing the base servlet to supply a Thrift processor to service the request. For the calculator example from the tutorial:

package server;

import tutorial.Calculator;

public class CalculatorTServlet extends TServlet {
 public CalculatorTServlet() {
   super(new Calculator.Processor(new CalculatorHandler()));
 }
}

Invoking the service is easy - you just use the THttpClient transport. Using Thrift over HTTP allows you to use all your existing high-availability and failover infrastructure, which can be attractive. (But also see this Thrift mailing list thread which gives some more detail on how Facebook tackles high-availability and failover.)

RESTful Web Services

RESTful Web Services by Leonard Richardson and Sam Ruby is a great book. It's about how to make the web more programmable, and tells you, through a great mix of theory and practical advice, how you can achieve this for the part of the web you're building.

It'll make you think about URLs. (Do you put state in query parameters or the path? See page 121.) It'll make you think about HTTP. (For example, the response code 201 Created, is used to show that the server created a new resource in response to a client POST request.) It'll make you think about the web.

I found it gave me a (conceptual) framework to design a RESTful API for an product we're building at Kizoom. Sometimes it can be a bit of a struggle to see how to make some operations RESTful (only four verbs remember!), but the design that emerged was actually very simple once I starting thinking about things the right way. Seems like James Strachan had a similar experience; after a rocky start he persevered and now has what looks like a great design for a Pure RESTful API to ActiveMQ via AtomPub.

Why are there no Amazon S3/EC2 competitors?

Amazon's storage and compute services (S3 and EC2 respectively) are widely seen as game changers. So, almost one year on from EC2's launch, why is it that there are no competitors in this space? One commenter on Artur Bergman's post entitled Amazon Web Services and the lack of a SLA made the good point that a "competitive utility computing market" would effectively solve any disaster recovery problems, and make such services even more popular.

Meanwhile, TechCrunch reports a rumour that Amazon will offer a MySQL web service by the end of the year.