Hypermedia and pubsubhubbub

by Hari in Architecture, Design, REST

Last week some folks from Google released a new lightweight publish subscribe protocol called pubsubhubbub that interestingly also includes a new an ATOM extension. This is one of the first attempts to solve the polling issue that currently plagues feed aggregators such as Friend Feed etc.
At the outset one thing to bear in mind is that this is not a mechanism that browser/desktop based feed subscribers can leverage. For that we will have to wait for Web Sockets to become standard. As far as pubsubhubbub goes you need to be a distributor or an aggregator of some kind to find this useful, very useful indeed.
More information can be found on the project’s wiki but the first 12 slides of this one presentation in particular I think explains the mechanism involved quite succinctly.
For those who want to see this idea in action I recommend watching the video where friend feed is shown leveraging this protocol.

What stands out for a REST enthusiast like me is that the way a feed describes its Hub server(s) in its Atom or RSS XML file. This is done via a link relation called hub(link rel=”hub”) .
Of late there have been many before whom I have had to be quite tongue-tied explaining the possible pragmatic uses of the notion of hypermedia. So you can imagine my excitement on seeing a link relation being used as a significant part of this protocol. In fact all the fun starts with that one link relation. This clearly is a humble beginning to popularize web-style messaging.

Okay…now I am off to build a hub. Should be fun!! Once I have it ready it will be time to convince an enter-pricey architect to use this idea. LOL :)!!!

HATEOAS Enlightenment

by Hari in Uncategorized

Finally some excellent arguments for why HATEOAS. For those interested in the details here is the thread on rest-discuss.

Clay Shirky’s note on Newspapers

by Hari in Uncategorized

There has been some significant discussion on the blogsphere about Clay Shirky’s recent post on the future (or the lack of it) of news papers. Here is a collection of some of his ideas that appealed a lot to me -

Revolutions create a curious inversion of perception. In ordinary times, people who do no more than describe the world around them are seen as pragmatists, while those who imagine fabulous alternative futures are viewed as radicals. The last couple of decades haven’t been ordinary, however. Inside the papers, the pragmatists were the ones simply looking out the window and noticing that the real world was increasingly resembling the unthinkable scenario. These people were treated as if they were barking mad. Meanwhile the people spinning visions of popular walled gardens and enthusiastic micropayment adoption, visions unsupported by reality, were regarded not as charlatans but saviors.

…When reality is labeled unthinkable, it creates a kind of sickness in an industry. Leadership becomes faith-based, while employees who have the temerity to suggest that what seems to be happening is in fact happening are herded into Innovation Departments, where they can be ignored en masse.

Round and round this goes, with the people committed to saving newspapers demanding to know “If the old model is broken, what will work in its place?” To which the answer is: Nothing. Nothing will work. There is no general model for newspapers to replace the one the internet just broke….It makes increasingly less sense even to talk about a publishing industry, because the core problem publishing solves — the incredible difficulty, complexity, and expense of making something available to the public — has stopped being a problem.

That is what real revolutions are like. The old stuff gets broken faster than the new stuff is put in its place. The importance of any given experiment isn’t apparent at the moment it appears…
And so it is today. When someone demands to know how we are going to replace newspapers, they are really demanding to be told that we are not living through a revolution. They are demanding to be told that old systems won’t break before new systems are in place. They are demanding to be told that ancient social bargains aren’t in peril, that core institutions will be spared, that new methods of spreading information will improve previous practice rather than upending it. They are demanding to be lied to.
There are fewer and fewer people who can convincingly tell such a lie.

If you want to know why newspapers are in such trouble, the most salient fact is this: Printing presses are terrifically expensive to set up and to run.This bit of economics, normal since Gutenberg, limits competition while creating positive returns to scale for the press owner, a happy pair of economic effects that feed on each other..

Any experiment, though, designed to provide new models for journalism is going to be an improvement over hiding from the real, especially in a year when, for many papers, the unthinkable future is already in the past…..For the next few decades, journalism will be made up of overlapping special cases…Many of these models will fail. No one experiment is going to replace what we are now losing with the demise of news on paper, but over time, the collection of new experiments that do work might give us the journalism we need.