Thursday, December 21, 2006

Hey Ma look at me! I do SOA now.

One of the worst things about SOA has been the band-wagon jumping by vendors. These have fallen into broadly three groups
  1. Hey look something new, bugger its not technology, quick lets develop some implementation stuff and claim the badge anyway.
  2. Hey look its a techy thing, we do that already don't we? Quick jig and bob's your uncle.
  3. Bloody hell that has a lot of Buzz, lets slap some lipstick on the pig and claim its SOA.
The first group include the likes of IBM, BEA, Oracle, SAP, Sonic and a few others. Companies that have recognised that they don't have the current products to do the business impact side of SOA, but have at least recognised that their technology stack needs to be different to older style technologies (I'm talking about IBM product here BTW not things like CBM). So Oracle have actually built middleware, IBM have abandoned the old MQ based technologies for new development and BEA have clearly split application development from business as a domain. I'd lob REST in this group too. Behind the scenes they'll all say that they see the business thing, its just that they can't see how to build or flog products that do that right now.

The second group are the EAI vendors and the vendors who had some sort of "component" based approach and are just seeing XML and WS-* as another implementation pattern. They've pretty much decided that its a techy thing and its just another protocol for them to handle. These are the people who can't believe their luck. 2 years ago no-one was buying EAI, suddenly its an "SOA stack" and its popular again. At least these folks though are misunderstanding within a specific context (technology), they say that SOA is important, they just tend to stress technology and implementation more than the first group, often because they can't afford the re-development costs. They too see the business thing, but they are even further away from being able to do it than the first group.

The third group is the worst though, these are the people with a particular world view and a particular line to pedal who decide that "SOA cannot be done without X", linked from this post is an article by IDS Scheer on how SOA "requires" BPM, indeed how SOA "starts and finishes with business process". IDS Scheer are far from being alone in this group, but this is a cracking example of the sort of thing that is wrong with IT.

Here we have a paper in 2006 that actually does the WS = SOA thing, something that actually proposes that Services should be created bottom-up and it is process, including the execution level processes that drive and define SOA. I've talked about POA v SOA before but to be brief, if you start with process and do process based definition then you are doing POA and are 100% not doing SOA. On page 95 of Enterprise SOA Adoption Strategies I discuss how business process works in an SOA context (and the similarity of process & service at high levels of abstraction), but this isn't want IDS Scheer or the other "business" modelling tools are doing, what they are doing is taking exactly the same model they had before and just going "hey look if we consume a WSDL we are doing SOA".

This last group is easily the worst and most disreputable, particularly as they claim that they can model businesses effectively and are the most disconnected from the technology. Their claim that they are a requirement for SOA without actually offering anything that is SOA is quite gobsmackingly bold faced.

Anyway I hope everyone has a great break and comes back in 2007 ready to face SOA as a business challenge rather than as just technical implementation. Oh and to people around the world, there are two British Christmas things that you need to get, firstly Christmas Crackers and secondly Mince Pies. Christmas isn't Christmas without gunpowder, a silly hat and alcohol laced titbits.

Technorati Tags: ,, ,

The perfect SOA environment?

At my department's Christmas bash last night the discussion was many and varied, ranging from the stupidest thing we've been asked at US immigration (an impossible to judge competition due to the level of entries), getting a bill through the houses of parliament to starting off in IT and your first language/OS.

Well my Boss cracked up with his first platform and it enable the dynamic provisioning of services, each service ran in its own dedicated partition and could be tuned, upgraded or deployed independently of all the others had a rigid definition for these service environments while enabling efficient communication via distributed shared memory and clustering. Development could be done in various different languages and still run on the same common platform.

So what exactly do modern platforms have over VME(Virtual Machine Environment), isn't this exactly what efforts like VMWare and the Hypervisor on Intel chips are trying to re-create today? While the concept of containment and deployment of individually active services sounds very like the goals of SCA.

This is one of the major reasons that SOA can't be about throwing away old systems and replacing them with new technologies. VME, if architect correctly, could act as a very efficient way of delivering certain types of services in an organisation, similar claims could be made for LPARs and other "older" technologies. If they are working and delivering effectively against the business goals, and are actually providing facilities not currently available in "modern" environments which are helping management and control then take advantage of that rather than ripping and replacing.

The perfect SOA environment is heterogeneous and takes account of what you already have and what you need to do, and is managed and evolved in line with the services and capabilities of the business. The worst is one where technology is being used as the driver and words like "Web Services", "REST", "BPEL" and "WCF" are being used as justifications.

Technorati Tags: ,

Thursday, December 14, 2006

Sad but it is December...

A simple game of blog tag for Christmas, on Sunday, Jeff Pulver started a game of "blog-tag" in which participants are asked to share 5 little known things about themselves, and then tag 5 people on their blogroll. Well as per the headline link I got tagged and hell its December.

Okay here are my five
  1. I hate horror films
  2. I'm nuts about snowboarding and watersports, I don't just mean I like them but that I'll drive 5 hours from SFO to Tahoe for 2 days and catch the red-eye to Toronto when there are only 5 open runs at Heavenly type nuts
  3. Every father in the world thinks his kids are the best... but only I am right
  4. I think Java (and all other C syntax languages) are rubbish, and much prefer Ada/Eiffel
  5. I met my wife in an Irish Pub in Paris, we went to a club, chatted the night away ended up walking along the Seine and then having breakfast in a little cafe just across the river from Notre Dame.
So who shall I tag... well why not Stefan Tilkov, Mike Morris, Andy Hedges, Dan Creswell and Cliff Richard?

Technorati Tags:,

Why contracts give flexibility....

As per the last post there has been the standard "flashback" from a bunch of people who crusade first and think later.

So lets explain in simple terms how strict contracts give flexibility, and to make it really easy I'm going to use four examples, firstly REST (which the "don't validate" crowd follow) and secondly LEGO(r) which the "I don't understand SOA but I'm going to use this as an analogy" crowd try to go for. The final examples are... well I won't spoil the surprise... So I should cover lots of bases here

So first off lets look at HTTP, it has a very strict contract with a limited number of possible actions, GET/POST/PUT/etc and an extremely limited way of getting to those actions. Now interestingly the entire concept of REST is that this limited and tightly specified set of actions when rigorously enforced provides an infinitely flexible architecture on which to built things. So HTTP is in fact an area which has a pretty tight set of up front validation (try sending random packets to Apache or Firefox to see where it gets you) and an extremely limited and well specified set of actions with which to interact with the server.

So simply put the REST people who are claiming that you shouldn't validate are exactly the same people who are claiming that you should rigidly adhere to a tight specification and reject anything that (for instance) stops GET being idempotent. So here is a great example of a tight specification being used as the implementation approach for complete flexibility.

Next up lets take Lego, you have a "brick" it has a bottom which has set dimensions and a top which has set dimensions, amazingly despite limiting the specification of the brick to having exactly the same form and function top and bottom the potential for Lego is practically infinite, you can do Star Wars, Air Force One and really odd stuff. This is all managed via a very strict contract as to how the different bricks connect.

My third example is the wonderful world of IKEA. IKEA uses pretty much the same screws in every thing they do, they use the same sort of connectors in everything they do, and lots of times they use the same size of wood, just combined in different ways. Having tight specifications like this that mean they only need certain sizes of doweling or screw gives them an immense (and profitable) flexibility in what they can create.

Tight specification can often be used as the basis of flexibility rather than rigidity, but having these tight specification means that you, as an engineer, need to understand the boundaries within which you operate.

The final example comes from the wonderful world of Pimp my Ride and more particularly the world of tyres and "rims". Having a set size for wheels and a tight specification doesn't decrease the flexibility it positively increases it. There are a massive amount of tyre and rim combinations available so one car could have three tyres from one manufacture alone and a set of 4 rims from the first hit on Google. For the mathematically minded that is 12 different combinations on a single crappy Ford Focus.

This is why specifications are engineering, if you could say "I wish that I could just do this because its cool" then you'd be a liberal arts major. Having specifications can increase flexibility when you know how to use them and use them in a smart way. This is the reason that screws, nails, hinges, doors, trains and lots of other things obey a specification. Specifications are the best way to get things to inter-operate. The REST crowd should know this better than most with their mantra of "standard HTTP", but unfortunately too often people are beguiled by an idea which makes them contradict the benefits of what they are saying is right.

Specifications give flexibility because they tell people what can and cannot be done, people are then very adept at modifying their behaviour and their world to cope with these limitations.

It would be completely wrong to say that this was Darwin in action, but its completely right to say its how adaptation works.

Technorati Tags: , ,

Wednesday, December 13, 2006

Can we please be engineers not optimists?

Via Stefan Tilkov I came across this Mark Baker article and well I'm going to set myself up on the opposite side of the fence here, in fact I'm going to go over that fence, across the field and sit in the pub watching him sink slowly into a quagmire.

One of the worst things I see in IT over and over again is the rage against formalism and verification, its just bizarre how often it happens. Now Mark might have a great new idea for time dependent evolvable validation... but for me he is wrong in principle.

First of all lets start with a the basic tenant that everyone should hold dear

KISS - Keep it Simple Stupid

And another is one of the few new Agile terms that I liked which formalised an age old saying

YAGNI - You aren't going to need it.

And before I get into it also have a look at The second System effect from the best book in IT.

When dealing with 3rd parties a basic rule of thumb is trust no-one and CYA (Cover your ass) this means verifying both what you send out as well as verifying what you receive. There are very good engineering reasons for this. Lets say that you have said that there is a limit of two items per order, as that is the business decision. If someone sends 2344 you want to reject that straight away, and schema verification is a great way to do that.

Engineering means designing a system that works for the task it is required to do, and if one of the things it needs to do is allow change then it needs to allow that change in a controlled and measured way.

The concept that Mark puts forwards of validating only at the last possible moment is somewhat beguiling as it has the idea that everything will turn out right, but if the poor bugger on the order system is expecting massive numbers then the odds are he won't have coded it expect them. This isn't their fault, if you say "its 1 or 2" then its pointless him writing loads of code to handle a million items.

Validating at the edges however does require you accept that when change happens it may break things. But the reality is that most of the time this is what you want. if you are dealing with someone who suddenly sends in a new document with a field that says "by responding to this message you are agreeing to give us all your money and your first born child" then you'd like to know.

Validate as early as possible, make sure that things are correct and hold people to account as early as possible. I've seen companies lose literally millions of pounds (billions of dollars :) because they didn't enforce interface contracts effectively, this led to problems down the line and systems that were very hard to untangle.

There are an awful lot of stupid people out there and it is your job to protect your systems and your business from their stupidity, this means not trusting what they sent you and checking it yourself for validity. Optimism is not a good engineering trait, pessismism is. That is why you validate what you send to make sure it doesn't come back on you, and validate what you receive to make sure the other person isn't an idiot.

To use a physical engineering analogy, you check that the wing is put on properly as soon as it is attached, not by looking out of the window at 30,000ft to see if it is still there.

Technorati Tags: ,

Tuesday, December 12, 2006

REST URI naming convention

Over on the Yahoo SOA list there has been a REST discussion where I've continued to not see the benefits of REST for prime time business development....

But there was also a discussion about URIs and whether they should be opaque (meaningless) or sensibly named. I'd like to make a REST proposal

All URIs in REST must be meaningful, they should clearly articulate the type of resource and its place in the hierarchy, individual resource identification should be done via a GUID. The GUID is used to standardise the use of IDs and to provide a clear identifier of the meaningful and opaque parts of theURI.

would be a "good" URI starting point and
would be an individual resource identifier.
would be the customer starting point and

would be a specific customer.

To me the lack of agreement on naming conventions to REST is indicative of its prototyping feel. Agreeing that URIs MUST have meaningful names would make it simpler to debug, simpler for developers to understand and will clearly separate roots from resources.


Technorati Tags:

Monday, December 11, 2006

Predictions for 2007

Okay its time to don my cap of predictions for 2007, the following should be thought about as reliable as the average horoscope, i.e. I'm making them up off the top of my head.

Products and vendors

  1. First off 2007 will the year of the SOA technical "platform" not exactly news as quite a few people are claiming this today, but 2007 will be the year that really sees this become useful. With Oracle, BEA and IBM all looking like having pretty major releases next years its going to be an entertaining marketplace.
  2. Smaller vendors will struggle even more, the justifications for picking niche products will increase.
  3. The "rich and fat" ESB model will die on its arse. Products will start to clearly split the communications infrastructure from the application infrastructure.
  4. Microsoft will slip further behind in the enterprise space while they wait for Longhorn server
  5. IBM will finally admit that it does have a cohesive strategy based around J2EE and that the non-J2EE bits are going to EOL.
  6. Rumours of BEA being bought out by Chelsea FC will abound, then die away once Roman Abramovich realises they don't posses a top quality international striker.
  7. SCA will become the "accepted" enterprise way of doing things
  8. REST will be delivered into the stacks so they can remain buzzword compliant, REST advocates will denounce them both as heretics and as proof that REST is the "answer".
  9. Business level modelling will continue to be a pipe dream, filled either with overly complex tools or insanely technical ones.
  10. Oracle will buy some more companies, probably including some sort of registry
  11. IBM will buy some more companies, probably focused around provisioning and management
  12. Windows Workflow exploits will show up in the wild
  13. Some product vendors will finally get the difference between product and application interfaces and stop confusing the two.
  14. Questions will be asked about why you have to pay so much money for an invoicing process in an ERP.
  15. Java being Open Sourced will not be the big "wow" that Slashdot predicted
  16. ERP vendors will start to get their heads around SaaS licensing models
  17. Hardware virtualisation will become the "norm" for new deployments
  1. WS-Contract and WS-SLA will remain in the future while WS-* concentrates on more technical challenges.
  2. WS-* will continue to be plagued by insanely simple bugs in various implementations, but vendors will hopefully each have just one WS stack (rather than all having multiples like they do now).
  3. BPEL 2.0 will go up a hype curve like almost no technology in history... people will then complain about their visual COBOL applications being unmaintainable.
  4. WS-* will split into competing factions, those that think everything must be done in "pure" WS-*, and those that think that sometimes its okay to not use the standard way if its actually simpler.
  1. REST will start re-creating the sorts of things that WS-* has, so await "RESTful security" and "RESTful reliability" as well as "RESTful resource descriptions" being bandied about.
  2. REST will aim for a MIME type explosion, this won't get very far and lead to lots of "local" standards that are nothing of the sort.
  3. REST will split into competing factions, those that hold to the "literal truth" of the REST paper, and a more progressive sect who treat it as a series of recommendations that are to be applied with thought.
  1. IT will continue to not care about the TCO and will focus on the cost of development
  2. Some major IT horror stories will emerge based on SOA and REST "failures" the reality will be that the project was screwed from the start but it was a damned fine scapegoat
  3. More engineering and measurable solutions will be required by the business
  4. Business will demand more visible value from IT
  5. Offshoring will continue, and South America will rise further as an offshore location
  6. The business will want to see IT clearly split the utility from the value
  7. IT will continue to focus on technical details and miss the business big picture
Well that is it for starters like all good horoscopes there are some specific elements that won't come true and a bunch of generalities that I can claim did. But my big prediction for 2007?
  1. Sun will finally get their act together and pull all those brilliant minds into a cohesive enterprise strategy and ditch all the fan-boy bells and whistles that have dogged their recent past.
Well I can dream can't I?

Technorati Tags: , ,

Sunday, December 03, 2006

SOA is people

With all this REST v WS-* type of arguments flying about I thought I'd remind everyone of the most important thing in delivering successful Service based projects, systems and enterprises.
Yes folks the thing that will actually make or break your systems in the majority of cases will be the people. This means the talent of the people defining and delivering and the cultural changes in the wider organisation to accept and take advantage of the services effectively.

All too often in IT's obsession with technology we argue about the pointless and ignore the critical. If your SOA strategy and direction isn't centred around the people and practice changes, then it won't deliver the benefits you expect.

Technorati Tags: ,