dinkatron

distributed key-value stores

2009-07-03T14:29:00.001+01:00

NOSQL rallycry for the distributed key value stores a.k.a distribute cache a.k.a. big hastable in the cloud. Didn't you know RDBMS is sooo last century? Not that the DB-vendors are going to be shaking in the boots anytime soon. RDBMS is going to be around for a long long time, but lets face it they just aren't sexy and there is lots of interesting technical stuff going on in the grid world.

Kohsuke fuses lego and nerd (as if that crossover needed more attention)

2009-06-09T16:47:00.001+01:00

Lego project - I'm not sure why I find this so fantastic, it's not the way he causually applies the Miller cylindrical projection to lego, it's that in my mind, there's a small bored child wandering away, muttering Daddy's gone all mental again.

YAAR (android rumour), but a juicy one

2009-06-08T16:01:00.001+01:00

Rumor: Sony Working on an Android Walkman - makes a lot of sense, pmp's don't compete on just hardware anymore, these days its all about the software. Sony's current walkman beats the iPod on hardware terms, but I would rather an iPod touch for two reasons both software:

web-browser - Sony's Netfront just doesn't quite cut it.
app-store - I travel a lot, so time-wasting is a high on my list.

Android provides a route to both - this would be great!

First law of computer science fires again - SimpleDB

2009-05-21T16:43:00.001+01:00

We like SimpleDB, we could get started with it quickly. What we didn't like were the usage restrictions, putting attributes up one at a time, we have a lot of attributes to fire up there on a continuous basis, but while we were getting to grips with the basics, the first law of computer science "wait long enough and the requirement will go away or someone else will do it" fired and we got batchput (25 records per request) - which is a lot better (but hey what about 1000). This was critical for us, since uploading records is something that needs to happen quickly - there's a timeliness requirement for us.

The next part of the problem was querying. We are limited to 250 records per select. So larger returned data sets which for us can be common given the current limitations of the select expression language, mean multiple requests. So we were very happen when the law fired again and the Amazon Web Services Blog: New SimpleDB Goodies: Enhanced Select raised the limit to 2500 items per request.

So our faith the AWS will keep putting some investment into SimpleDB is well placed!

Now if they can only add some operators to their select language: distinct, avg, min, max, sum we would really be cooking.

Emergency satire

2009-04-23T10:47:00.001+01:00

The sat. morning newstalk political satire has started blogging. Excellent. Check out this parody Johnny cash song: Lenihan Comes Around | The Emergency

Sayonara Ruby, Bonjour Scala

2009-04-02T11:25:00.001+01:00

The Register reports that the public ruby-shaped road accident that has been continuing twitter outages has finally led to the ejection of ruby in favour of functional JVM-hosted scala. The real winner here is the JVM and access to pre-existing Java API's. Must start looking into Scala - the Java Posse are always going on about how much they like it and being hosted on the JVM is a big win for them, as it clearly is for Twitter.

Twitter doesn't talk about why moving to JRuby was not an option for them (which is JVM hosted), but presumably the functional aspects of Scale w.r.t concurrency. Functional languages are extremely suited to this at a programming level - one of the reasons behind choosing Erlang for facebook chat. Plus Scala's type-inference is a real boon for programmers used to the static-typing support in IDE's.

So time to get a book and have a look-see.

Open Cloud Manifesto

2009-03-30T10:01:00.002+01:00

The Register just put up details of the Open Cloud Manifesto. This document can be summarised as "clouds are great, clouds with open-standards would be better". Common standards for security, data interoperability and portability, metering, monitoring and management. This is obviously a good idea "lets vote for open standards", but it is a tall order. Microsoft is miffed because (a) it wasn't invited to the manifesto-drafting tea-party and (b) because it is early to be drafting standards. It may have a point on (b) certainly for the M3 part (metering, monitoring and management). However two concerns are so critical to cloud-users that they deserve special accelerated attention:

Data portability ("Your cloud is useful, but I want to be able to get my data back!") - there's a working group dataportability.org that has already garnered some support (Google, Microsoft, etc) mostly driven by the social networks. Myspace, Google and Facebook are attempting to be the central-site that maintains the "record" of your social graph (who you know, what you like, what groups you join, how you communicate). They want your data to sell advertising plain and simple. For this, they provide some neat services, but lets be clear your data is the crown jewels and they are interested enough in allowing other sites to access your friend graph, but in a kind of hands-off way - no caching - kind of way. This isn't really portability. So this concern is still very much valid.
Security - how do I control access between me and the cloud and between the clouds themselves that manage my data. Luckily OAuth is now effectively a de facto standard here and so it is ready to be blessed as the official cloud standard.

However, the cloud manifesto goes further than open standards. It its section "Principles of an Open Cloud" point 2 is:

Cloud providers must not use their market position to lock customers into their particular platforms and limiting their choice of providers.

and pigs might fly.

SimpleDB

2009-03-24T13:02:00.001Z

Started playing around with Amazon's DB. It's still in beta and there are a few niggly restrictions, but it is usable and "does what it says on the tin". It's a simple cloud-based storage mechanism for storing single rows of arbitrary data. The emphasis is on simple - single table stuff. So this is not going to be a replacement for your well structured database. However, one of the things that you notice when your system starts getting a lot of traffic is that there is an awful lot of data that is simply flowing over your servers that you would really like to store, report on and build some new cool things with. If only you had somewhere to collate and store this information. Enter Simp[leDB. Sure I could invest time and energy in bringing a data warehouse on line (if I could get it into the production setup) - which would certainly address some of simpleDB's usage restrictions, but this sort of task is exploratory. I want the freedom to start instrumenting and collecting data basically on a whim without incurring significant setup costs. Some stats will definitely be useful, plugging holes for current decision-making, others are more of the "suck-it-n-see" variety. Using simple DB solves two basic problems for me over just using one of the (many) mysql db's available to me:

There's an overhead with storing information in a production database. It needs to be properly setup in terms of disaster recovery, this needs to be tested. It needs to have a pruning and archiving schedule negotiated with the support people. Then there's the testing. This is a lot of pro-forma setup stuff which really is not what I need to have to invest in upfront. Sure if this thing takes off or outgrows SimpleDB's restrictions, then I can revisit this, but for now I don't want any roadblocks.
Neatly sidestepping organisational boundaries. We have many environments where I would like to gather data, but if I have to negotiate with each environment for storage, then I'm going nowhere fast, but moving the problem outside the network neatly sidesteps these issues. It also provides a natural place for me to centralise the information, something which for network partitioning issues would also be problematic to gain approval for.

In my mind these are both agile issues (start prototyping quickly and not having to get too much organisational buy-in to get started) which having an external cloud-based mechanism neatly solves.

Minority report UI video

2008-11-18T12:47:00.001Z

Pretty amazing video about the g-speak system that does the whole Minority Report gloves and computer interaction thingy. Microsoft surface - pah!

Nice graphical overview of US Spending

2008-10-26T10:22:00.001Z

Via Gizmodo fantastic images on how US spending breaks down for the main categories (defense, health, etc). You can see the interactive map on wallstats. And it looks nice to boot. Puts the 60 trillion CDO's somewhat into perspective (approx 20 years of US total tax-receipts).

Transactions, SOA and Asynchrony

2008-10-08T18:17:00.001+01:00

Gregor Hohpe is currently thinking about conversation patterns, this is excellent news. His book Enterprise Integration Patterns is really a excellent work on categorizing the different ways we have been connecting systems together. It is one of those books that you go, "of course, why hasn't someone done that already?". EIP is reallly about the kind of ways that we pass messages between systems (message-oriented processing), for example router-patterns, queuing patterns, etc. Conversation patterns are a higher-level and represent sets of exchanged messages.

From this point of view, they should be entirely specifiable in BPEL, since BPEL can be used to specify a sequence of exchanged messages. Now BPEL is normal used to implement a Business Process which just happens to exchange messages between peer systems, but it can also be used to verify that a set of exchanged messages between peers conforms to its specification - e.g. that message A was received before message B. In fact, this is how we test our own BPEL engine, we use BPEL to implement the conformance tests for the BPEL 2.0 specification.

The conversation patterns emerge from work on "Your Coffee Shop Doesn't Use Two-phase Commit". Which makes the point that most human systems don't use two-phase commit, possibly because humans don't support a XA-Resource API :-). We should remember that ACIDity and 2-phase commit are artificial inventions which stem from a centralised planning viewpoint. The real world doesn't use them. The internet mostly doesn't use them for peer-to-peer interactions. Of course, this isn't really news, BPEL as a language is built around the notion of compensating actions, effectively dropping transactions as a concept for loosely-coupled SOA systems. And BPEL is on version 2.0.

So what kind of conversation patterns could we dream up? Well Intelligent Agents came up with quite a few:

Dutch Auction
Contract Net protocol

Though these are quite complex protocols, so maybe too much. Some simpler ones are:

Subscribe to Events (subscribe, receive event, ...., eventually unsubscribe or go missing).
Submit Job ( submit job, get job ID, poll job ID, or recieve notification or job, cancel job, etc).
Submit Task (submit task, transfer task, take task, relinquish task, complete task, abandon task).
etc, pick your favourite peer-to-peer protocol and generify it, e.g. Ask a question, expect an answer -protocol

So what do we hope to get for this. Well if we can generify some of these protocols, we can make them interoperable. Does this mean they have to be SOAP-based. Nope it doesn't. But notice that they are all services (i.e. realisable by a single entity), for example the event service, the jobs service, the task service. So they are specifiable in BPEL.

However, there are a range of conversation patterns that cannot be specified in BPEL. These are true peer-to-peer protoocols. BPEL can only specify the message exchange semantics for one peer (typically the service provider), but if we have true, peers and there is no central authority, or entity realising the service, then it cannot be specified in BPEL.

Cloud computing and iPhones/iTouch

2008-09-19T16:52:00.001+01:00

Currently I'm often in the US for work, which is handy because work is close to an AppleStore and invariably I just have to go there and buy an iPod. In fact, given the exchange rates, I've had to go there every single time I've visited the US this year - there's a lot of people in Ireland that need cheap iPods.

So the current crop of pre-Xmas iPods arrived two weeks ago. Now I'm not sure I'm tempted - I have a 2nd-gen Nano and given that 4th gen are going back to 2nd gen form-factor and unusally for Apple kit, my 2nd-gen Nano is still going strong with battery life despite being used (and dropped) continuously.

But there is the new iTouch. It is pretty. I kinda want one - they are cheaper and slightly better than the old ones. I reason to myself that I want one for browsing the web (regardless of the fact that I'm pretty much connected to the net for at least 8 hours a day). I reason that I could have the holy grail, ubiquitous, fast, hassle-free access.

A lot of people are moving as much of their life (mail, docs, etc) onto cloud computing platforms (e.g. google/gmail/gdocs), meaning they can ditch the luggable and get a new sub-notebook / netbook. But I would go further. Why can't I pretty much do most quick tasks on an iTouch like formfactor.
email
banking
government services
messaging
light web-browsing
reading docs / pdf's.
social networking
We are about to reach the point where the majority of new data generated daily will not be generated by corporations, governments and businesses, but by individuals, primarily using social-networking sites. Will there be a similar tipping point where most of this data is coming not from PC's, laptops or subnotebooks but from iTouch / blackberry devices?

If so, doesn't this mean we have a lot of work to do? In the last wave of mobilisation, when the dangerously oversold WAP technology was being pitched as the 'mobile internet'. A number of banks put some part of the banking systems online. But the limitations of the technology really hampered solutions and most were failures. The limitations nowadays are not about the protocol, the hardware or the bandwidth. They are about the screen and the input mechanism. This is where a lot of the thought of the second-wave of mobilisation needs to happen. Using the limited screen space to maximum effect. Any application that I habitually use today online in a web browser should be possible on an iTouch. Not some limited feature set. The whole thing.

This means no long HTML forms, but paged forms are okay. I should be able to partially save information (park it while I answer a phone call). Pre-filling / guessing information would be useful. Providing standard information from my iTouch to supply information (hint semantic tagging) as well as have my learn information I provide to my various sites, to help me when I'm filling information on other sites.

Cool printer meets waterfall

2008-08-14T11:44:00.001+01:00

This Cool Waterfall in Japan naturally mixes dot-matrix style printing with waterfalls, to allow design messages to be scrolled onto the waterfall. The next obvious step would be to get a gamepad hooked up for some "downhill-skiing" waterfall game-action.

Lisbon Treaty - Day 3

2008-06-11T21:01:00.002+01:00
So from an Irish perspective the Common Foreign and Security Policy (CFSP) parts of the Lisbon Treary are perhaps one of the more controversial parts. The common fear is the creation of some sort of EU-super army that will have thrilling adventures in places that most people would have difficulty spelling. Lisbon provides nothing to worry about in this regard, because the EU already created it in 2004, it's called the European Defence Agency.

My primary concern is that it would require us to actually spend money. I know, you were thinking about neutrality. Face it our health service is wonky and the Ireland's finances are a fairy story (we seem to have misplaced a billion in tax revenue somewhere, perhaps Bertie could save the day with some hot gee-gee money, but I digress) - do we really want to spend money on shiny new tanks? Here's EDA's information about how much we spend on defence-note how low we are as a % of GDP. This is a good thing. Unfortunately, Lisbon Treaty states:
"member states shall undertake progressively to improve their military capabilities".
That sounds expensive. Now Lisbon supporters say that there are no targets / requirements being set so we shouldn't worry, but that's pretty cold comfort. Once an objective like this is agreed to, targets may not too far behind. However, we can be pragmatic. we are already part of the EDA and so we have to commit to some spending (our guys walkie-talkie things need to be able to the Germans' talkie-things for instance). It seems unlikely that we can be forced to commit high-levels of GDP spending to the military, either theoretically or practically - but it is a bit unclear.

What Lisbon does is interesting. It sets out two stalls. The first is a wide brief where the EU as a whole can get involved in defence activities outside its borders, but this is subject to unanimous decisions by all states. The second more worryingly is called Structured Co-operation, basically a subset of Member States banding together to go on jolly foreign jaunts again under a pretty wide brief (UN-sanction actions, stabilisation of states, defence, etc). Within 3 months of the passing of the treaty, states can band together to create a new combined force. This is inherently a new militaristic focus to the EU, there really isn't another way to look at it. How you view this is up to you. I'm hot-n-cold on the issue. I remember Kosovo, where the EU failed to act and UN personnel failed to protect lives. So I'm suspicious, but not totally against the idea.

In any case Ireland cannot be forced to join. It would require a goverment decision, Dail approval, and UN authorisation for us to get involved.

I would prefer if this whole aspect of the Lisbon Treaty simply wasn't there. It is definitely a genuine concern. Not because it commits Ireland to any given action, but because it involves a ramping up of the militarisation of the EU (which started off as a purely economic union). I am enough of a realist to recognise that there are already a number of supra-national mechanisms by which member states can already engage together and that having such engagements inside the EU makes them to some degree more accountable.

Lisbon Treaty - Day 2

2008-06-10T22:02:00.009+01:00
The main criticism about the EU is that it is pretty undemocratic This is mainly because
The Commission, you know the brain-trust which controls policy and alone has the power to initiate legislation, is completely unelected. This will not change under Lisbon.
The Council (of ministers) which is one of the two legislative bodies meets in secret - this will not change under Lisbon.
The Eurpean Parliament, the place where politicians go to die, is being cast as the big winner from Lisbon. The Parliament is the only directly elected part of the EU, but its powers aren't terribly impressive. Basically the drill is, the Commissioners, those clever, unelected people such as Charlie McCreevy, propose new legislation, then the Parliament and the Council (I know I'm losing consciousness too) which is made up of ministers from national parliaments both must agree (codecision).

So the Parliaments powers are: propose amendments and say no. Not entirely stunning, but certainly not useless - afterall by simply refusing to sign-off the EU budget (due to massive fraud allegations) they forced the Santer Comm ission to resign. Try getting the Senate to do that.

Under Lisbon, the main change is that codecision is extended to most policy areas. Which means you might not want to be so flippant when next voting for your MEP. Do you really want Dana voting on energy policy? However, they still cannot propose legislation - so not ushering in a new democratic dawn.

Another change is that the Parliament gets to elect the President of the Commission (where the real power lies - the ability to make new laws). This is a good thing in terms of balancing power between elected and unelected officials.

There are some sops to making the EU more democratic. For example:
A citizens initiative where 1Million citizens (v. Austin Powers) can petition the Commission to bring forward legislation on a particular issue (such as an immediate ban on Westlife) . What the Commission has to do at this point is undefined and this smells like a populist measure that was tacked on to make the treaty more touchy-feely.
A role for the National Parliaments, not content making a mess of their own legislation, they now have the right to vent their spleens at EU legislative proposals.. If enough of them are against it then the Commission must review (that doesn't actually mean anything has to happen, the Commission can re-present exactly the same legislation, but they are required to say why the National Governments should mind their own business). Seems pretty toothless.
So overall if you were hoping that Lisbon was going to make the EU more democratic I'm afraid I don't have entirely good news for you. It does make it a little bit more democratic by extending the areas which the Parliament has oversight on, but this should be thought of as reform (with a small 'r').

Lisbon Treaty - Day 1.

2008-06-09T22:49:00.002+01:00

So after reading the rather helpful referendum commission documentation on Thursdays upcoming lisbon treaty, it seemed pretty straightforward. If (and only if) you wanted a more integrated EU, reform of the institutions was necessary. If you aren't interested in tighter EU integration, then you should vote no on Lisbon.

Okay, first hurdle passed, I am generally in favour of more integration and would like EU-decision making to be reformed. So the next question is: Is the Lisbon treaty:
going to help streamline decision making.
be more democratic (it would be difficult for the EU to be less democratic).
generally be in Ireland's favour.
Hmm. Tricky. I downloaded the Lisbon Treaty and tried to read it, but I and most of the country simply aren't qualified to have a real opinion on the basic text. Now I don't necessarily have a problem with that, I have probably never read the text of any legislation, it has never seemed necessary for me to do so in the past, relying like everyone on summary information - so I don't see this as a problem which negates one of the common memes circulating 'It's too complicated to vote on'. I don't buy it, practically everything is 'too complicated to vote on' - but that rarely stops anyone. Other memes I'm discounting are:
There's no Plan B, Plan C. - Like I care.
Our European Overlords will be deeply unhappy if we vote 'No' - scaremongering (plus at times it seems nigh impossible not to upset the French).
The No lobby are a bunch of borderline crazies, US MilitaryIndustrialComplex Stooges, crypto-Catholics - Well would you want to marry into that family? I'm watching the Question and Answers debate and the tag-team of Declan Ganly (libertas) and Mary Lou (Sinn Fein) on the No side are frankly unnerving - Declan Ganly wins on mis-information terms. OK I admit it, I would probably have been guilty of a little of this sentiment - but actually lots of people are against the treaty.
Corporation Tax will be raised (despite us having a veto). Senator Shane Ross uses this fear to encourage a No vote on the treaty. Now I'm no fan of Senator Ross, he is annoying, but he is not insane. His argument is that those trickster French are simply biding their time until the dullard Irish vote Yes and then they'll be raising corporate tax rates so fast it will make your little potato-shaped head spin. His argument is this, yes we have a veto on tax matters under Lisbon, but the French will use some Jedi mind-trick to to make us forget to use the veto when they propose harmonizing tax-rates. This doesn't make sense - we have a veto now and we will have one post-Lisbon, if the French have such Jedi powers, they can force us to do it regardless of Lisbon.
Enhanced Cooperation will be a back-door to raising corporation tax - the "Your veto is useless" argument. No it won't. First-off enhanced cooperation doesn't directly involve countries that do not want to take part in the enhanced cooperation. Secondly enhanced cooperation has never been used (people mention Euro and Shengen, but these didn't actually use this facility). Thirdly, to use this procedure requires agreement from all members. Finally, this power already exists.
We'll lose a European Commissioner for Five out of Fifteen Years - OK this seems like a good thing - have you seen Ireland's contribution so far? So we get exactly slice of this action as all other countries. Seems overwhelmingly in our favour.
The Qualified Majority Voting - QMV of The Council (see below) will halve Ireland vote. Our vote will remain the same (7 votes), but larger states will get proportionally more votes (based on population size). This had led to a lot of commentators claiming that our influence will be diminished. This is mis-information. QMV involves a double-majority. Those claiming "halving" are conveniently forgetting that it requires at least 55% of votes and 65% of member states (this second part gives us equal status with other countries).
SIPTU, the Farmers, The Union of Tap-dancing Plumbers are calling for a No vote - none of these groups is voting on what is contained in the treaty. They've ruled themselves out of consideration.
All the other countries have already agreed to it - so if we reject it, we are rejecting the wishes of 26 other national governments (John Bruton's line). Tough - that is precisely the decision you are asking me to make.
So that all seems pretty simple, right. Onto the Forum on Europe - a non-directive counselling service for crisis voters. This was essentially an extended talking shop where people actually got to debate the Lisbon Treaty. Now it provides a much more comprehensive summary on Lisbon. So I started reading this and then realised that my total ignorance of EU structures was a hurdle. So here's a quick summary:
Council of Europe - this is actually the oldest EU organisation and has 47 members (so a lot of non EU-members). It worriesabout human rights and has the EU court of Human Rights at its centre. This is not affected by Lisbon.
Council of the European Union, a.k.a Council of Ministers, a.k.a The Council - This is one of the two legislative bodies of the EU (the other being the parilament). We will continue to have one minister from each country. This is the main body that will be affected by QMV (see above) the main additions are a new High Representative on Foreign Affairs (and a dip corp to support it). I think this is generally a good idea. The EU is a powerful organisation that consistently punches far below its weight on an international stage. It is time to fix this.
European Council - okay at this point you probably think they are taking the piss - were they stuck for collective nouns for European politicians? The European Council is the highest body of the EU made up of heads of state/government and President of the European Comission. This has no formal powers, it is not even an official institution of the EU, but it defines the policy agenda and is arguably the centre of power. The rotating president will be replaced by a President elected for 2.5 years at a time (max 5 years).
European Commission - this is the executive branch of the European Union - currently one comissioner per member state. They represent administrative areas, e.g. Charlie McCreevy is Commissioner for the internal market - which somehow involves proposing Software Patent Legislation whenever he's bored. This clearly is affected by Lisbon - but in a good way. The other alternative would be to invent some new administrative areas (Commissioner for Fun, Commissioner for decent Television, Commissioner in charge of investigating rigging of Eurovision voting) at tax-payer expense.

OK that is enough for Day 1. So far I think round 1 to the Pro-Lisbon camp, there seems very little that is scary (and quite a few useful things).

Apache wicket: First experiences

2008-05-24T10:52:00.002+01:00

We've recently started using Apache Wicket here in Workday. I have quite a bit of experience with front-end presentations systems in Java, starting with jhtml/ATG dynamo (ancient history pre-cursor to JSP's), XSLT/XML/HTML content rendering, cocoon, velocity, JSP's, page-flow, taglets, struts, JSF, spring MVC - luckily not all for Cape Clear / Workday (that would be crazy). Most had some useful bits, but serious drawbacks. For example, about the best thing I could say about struts is that it is "better than having nothing at all", it's main problem is that developers always had to think simultaneously in terms of pages/JSP code, actions, javascript (since there was always javascript involved). It really didn't simplify anything.

The continuations-style, where you code in terms of putting components on the page and then configuring event-handlers is a very powerful concept. It attempts to apply the sucessful graphical-component programming models of Swing/AWT to web-pages. In this model, the front-end framework manages the heavy-lifting of associating web-requests with pages, instances and event-handlers. Obviously this state-management costs (in terms of sessions), so YMMV in terms of framework you choose, how you use it and your expected load. On the standards front there is JSF which is popular. However, for me it is overly complicated and heavy (in terms of it's construction - but I hear they are working to reduce that). Also, you still inevitably end-up with quite messy JSP's (not scriptlet ugly, but still - not nice and more trouble to maintain than it is worth).

This is why wicket is so appealling. It is another continuation-style / page-component model - but it's philosophy is to leave the web page uncluttered and thus easy to maintain and share with web-designers. The central idea behind wicket is to have two parallel models. Firstly you have the web-page component model. This is very familiar to anyone who has ever programmed Swing/Swt. Even the naming of the components are deliberately similar. Here's an example hierarchy for a simple form.

public class MyWebPage extends WebPage {
private String name;

public class MyWebPage {
add(new Label("title"));
Form form = new Form("myform");
form.add(new TextField("name", new PropertyModel(this, "name")));
form.add(new Button("hit") {
public void onSubmit() {
// do something - this is the event-handler
}
});
add(form);
}
}

The corresponding web-page is shown below. Note how clean it is. Only the wicket:id's are used to identify which bit relates to which bits in the corresponding java component model.

<html wicket="http://wicket.apache.org/">
<head>
<title wicket:id="title"></title>
</head>
<body>
<form wicket:id="myform">
<input wicket:id="name"/>
<input type="submit" wicket:id="hit" name="Push Me"/>
</form>
</body>
</html>

Wicket's strong-point is it's "do-it-all-in Java" approach and leave the HTML for just being the view (of the MVC). This is in start contrast to JSP which mixes logic directly into the HTML. The comes a point when working with it, where you stop thinking in terms of web-pages or the wicket framework and just laspe back into thinking in terms of java object models (which is really where you should have been thinking all the time). Wicket just helps you associate this java object/instance hierarchy with web-requests, basically it is really good at getting out of the way of you getting the job done.

Other nice things are:
back-button support (which is a failing of a lot of continuation-style frameworks and flex-style plugins).
data-table/binding support.
stateless pages (if you want your pages to be stateless you can do it).
bookmarkable pages
integration with acegi security.
unit-testing support.
ajax support (including contributions for scriptaculous and prototype).
it make sense - I try out undocumented stuff on the basis that it "should do X" and generally it does.
access to the source (invaluable).
And lots more. The bad is the documentation. Generally the information is there (either on the forums, or in the reference material), but it can be patchy and hard to find. There are a couple of books (being finally released over here next month) which should help - will definitely buy them.

So far we have developed three sets of new functionality. Each one involves searching for data, presenting it in paged tables and allowing editing with valdiation. The first one took us a couple of days (due to the documentation and lack of experience). The last two have really just been stamped out incredibly fast, now that we are a little further along the learning curve. I am astonished at how productive you can be.

xmlsoap.org having a bad day.

2008-04-22T15:04:00.002+01:00
Microsoft is doing fun stuff to the xmlsoap.org site.

The schema for WSDL, which used to be located at: http://schemas.xmlsoap.org/wsdl/
(okay it's in the text of the spec at http://www.w3.org/TR/wsdl), has gone AWOL. This is probably winding it's way through multiple build servers as we speak.

Luckily wayback engine to the rescue: http://web.archive.org/web/*/http://schemas.xmlsoap.org/wsdl/

Fantastic. Now if they could only get svn working so I can do internet checkins.

iPhone IE vs UK - guess who is being ripped off

2008-02-28T12:33:00.006Z
The iPhone tariffs for Ireland are out. Unlike US and UK tariffs the data is not an all-you-can-eat affair.

Here's the Irish one:

and here's the UK one:

Notice 1Gb cap on the Irish one and incredible difference in minutes and scabby texts. And are they really charging for voicemail, that doesn't sound right?

New Laptop

2008-02-23T10:19:00.001Z

Upgraded my laptop at home to XPS 1530. Of course I considered an Apple (given that I'm in the US regularly), but even at dollar prices it is still well overpriced. The build quality is really nice (never thought I'd say that about Dell) and the screen is really good (although you cannot get 1920x1200 in the 15.4 form-factor - whereas you can get it if you switch to the much lumpier Dell Precision Laptop).

Overall I found the dell site pretty annoying to navigate when purchasing. For me the key features are:
Screen Resolution - I develop in Eclipse and anything sub 1600x1050 just doesn't cut it, but the Dell site doesn't let you filter/narrow on screen resolution, just overall form-factor (15 / 17 inch). For me this is the most important feature.
Processor (obviously)
Hard-drive speed. This is really confusing - different models support different drive speeds (annoying).
Weight - for instance check out this rather amusing sales line on the XPS 1710: "8.71kg of media muscle". nearly 9Kg!!! They should develop some sort of "Dell-Fit" exercise program to go with it.
So what about the supposed crappiness of Vista. Well I've shoved 4Gb into it, so Vista runs very, very smoothly. So no problems yet.

Does McCreevy have no shame?

2008-02-16T09:58:00.001Z

You really have to question whose interests McCreevy serves. It certainly isn't consumers. The irish commissioner for Europe's Internal Market is backing a proposal to extend copyright from it's current life+50 (expires 50 years after the death of the artist) to life+95 (note in the UK it is life+70). Now I'm for Copyright for artisitic works, but what is patently missing from the proposal is any real justification for why the terms need to be extended (that is beyond the fact the the BPI and their European counterparts are lobbying hard). Is it just me, or shouldn't an internal market commissioner be mostly against extending protectionist measures. But given his previous position on software patents, we really shouldn't be surprised.

Hilariously the Tory opposition in the UK has agreed to back the proposal provided the BPI provide ""positive role models for young kids to look up to, draw inspiration from, and aspire to be". So lots more X-factor for everyone - brilliant.

Workday Acquires Cape Clear

2008-02-06T17:35:00.001Z

Workday has bought Cape Clear. So from today I'm a Workday employee. This is very exciting, not least because Workday are an amazing organization, but for me the real win here is being able to focus our software on making integrations simpler to write, run and manage. Workday are a Software-as-a-Service (SaaS) ERP player (HR, Financials, ..). They figured early-on that integration was a key requirement when selling SaaS solutions. People love SaaS, but how do they connect it to their own systems? Workday's acquisition of Cape Clear is a signal of just how critical that requirement is.

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BPMN and BPEL suing for divorce

2007-12-05T13:05:00.001Z

Interesting article over on InfoQ: "The Seven Fallacies of Business Process Execution" which makes the argument that combining BPMN and BPEL is a waste of time. I have to strongly agree here. I have many objections to suggesting that your analysts write a Business Process in BPMN and then generate BPEL for execution. Firstly, is that you expect analysts to write correct BPMN processes. Secondly, only a subset of BPMN is actually compilable to BPEL. Thirdly, round-tripping isn't possible. However, mainly this whole approach is doomed for simple fact that BPMN is complicated and BPEL is complicated. So even if you could do it, debugging, problem-resolution and maintainance would render such solutions unsupportable in practice.

However, it makes the contention that everything you need to solve BPM already exists. The magical solution consists of:
BPEL
SCA - Service Component Archtiecture (composite application framework).
Human Task 1.0 - Web service for defining and scheduling tasks to be completed by humans (e.g. soliciting input / approval).
Web Services (that do other stuff in the business process).
So the solution seems to be BPEL to model the business process, Web Services to implement specific functionality (e.g. createCustomer), Human Task to represent tasks that humans are required in the loop for (e.g. approve this loan decision ? ) and SCA as a means to deploy all these various bits together a composite application. While I agree with the sentiment here, I would caution that Human Task is unproven and ditto for SCA. But we can boil this down to the basic message of BPEL orchestrating Web Services (where some of those Web Services are concerned with interacting with Humans).

This is the approach Cape Clear advocates and the message is fine as far as it goes - but here's the problem. Where do you start to design your process? It is BPEL outwards? Do I describe things in WSDL and then define them in BPEL and invoke on Web Services. What about interface design? Sure even Human Task can be coupled with some rendering technology to allow simple forms to be generated, but that is for back-office work. What about front-office / customer-facing web site, where does this fit in. So this isn't a development framework, but a collection of things that you could cobble together to form a solution. How are such solutions extended and maintained (new tasks, modified task descriptions, etc, etc). For me, quite apart from the unproven status of Human Task and SCA, it seems very early days for this approach - but in theory it has merit.

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Zombie Cockroaches

2007-11-30T13:14:00.001Z

Checkout slashdot for links about wasps that create Zombie Cockroaches (including a movie).
What's next? An ant wielding a sawn-off?

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Building a Android Application

2007-11-12T20:26:00.001Z

Interesting YouTube - A first hand look at building an Android application about building a Android application. Highlights:

Eclipse project support. With emulator support.
Write Java to develop a new application - pattern is to extend an existing class for controller / behaviour, use XML for visual layout (view).
What is apparent from looking at this, is that the capabilities provided by the API are nice, but basic. I think someone needs to Spring-ify this API a bit more - a lot of the code (and to be fair there isn't much required) looks like stuff that could be configured rather than programmed (freeing developers from having to know specific API's - at least for basic stuff like listing contacts and tie-ing these to actions).

Still it is nice to see this kind of capability. Will be interesting to see how this compares to the Apple IPhone SDK when it arrives next year.