f3yourmind

It was really good to be part of a very topical subject at the JCSE Architecture Forum last night.  While these discussion are so valuable, the things that surface can only be glossed over, largely because of time constraints.  I end up feeling a very satisfied and energised but a part of me feels a bit hollow.

So here are some of the things that surfaced at the Forum, and my narrow, unworldly opinion on each (i.e. I’m just trying to fill that hollow feeling).

When we talk about architecture, we need to define what we mean by architecture?

In my talk it was a very simple view of architecture which, thinking back, I should have disclosed very early.  I am now applying from Kent Beck who talks about mutually beneficial relationships.   So I think of architecture as the mutually beneficial relationship between two or more things.  So what is a thing?  It could be  lines code in a method, methods in a class, classes in namespace, namespaces in code base, binaries in an application server, application servers in a cluster, … see where I am going?  Architecture is about creating beneficial relationships, and the 5 things I discussed are based on this view.  If you don’t know anything about the things, then you cannot create beneficial relationships.  From an agile perspective, the beneficial relationship that you create should only be beneficial based on your knowledge right now.  Tomorrow your knowledge changes, so the relationship may not be as beneficial as yesterday.  Time to change.

Building infrastructural architecture independently of functional requirements…

I am not convinced of the benefit of this approach.  In my limited experience, every business need defines the constraints or needs of the infrastructural architecture.  I find it hard to find the point of departure, yet there is a school of thought that suggests that function is orthogonal to the architecture.  Perhaps I just don’t understand this.  However from an agile perspective, I want to release early and there are many constraints on infrastructure from the business (for example, administrative processes like procurement of hardware).  I like to understand what these are early on, reach agreement on what we can release at the earliest and design accordingly.  Perhaps the first release is on lightweight infrastructure and that means we “limit” scalability.  So, I don’t design for beyond what I know is real.

Model Driven Architecture …

My view is more philosophical and abstract.  What is a model?  For me, a model is something intangible.  It is a way we understand something.  But we represent our models in many ways.  Through words in written or spoken conversation, in unstructured pictures, in structured notation like UML, even code is a representation of a model.

What do we mean by driven? I view it as a something that takes an input that produces an output.  In this case, we take an input, the model, and produce an output, an architecture.  So, I take an understanding of problem and use that to derive an architecture.  So, that’s nothing new here.  However, I don’t like to confuse driving out an architecture from a representation of the model.  That’s different.  Now we are going beyond thought processes  into mechanical processes.  Then the challenge is about how to apply the feedback to the representation of the model – and that is what will make you agile.  Too much for my small brain.

Plumbing …

Yup, we do too much hand crafted plumbing!  It’s something that we have been working on for a long, long time.  I think convention over configuration, dependency inversion, meta-programming are all attempts at addressing this problem.  Some early success that I have experienced is on taking a polyglot approach. I am not talking about mixing general purpose languages on one runtime only.  I am also including domain specific languages. I’ve had some early success where using DSL to describe functional intentions and then generating a large portion of the plumbing.  Where I’ve suffered is when I mix concepts from different domains.  There is the domain of plumbing and the domain of the business.  Whenever I’ve mixed the two, it pains later rather than sooner.  Right now, the only way I’ve had some success is with aspect orientation and meta-programming.

@StatelessSessionBean …

Chris Naidoo is right.  That thing called J2EE and subsequent versions is just horribly broken.  It’s broken encapsulation and a whole lot more.  The fact that we now must use an annotation and not implement an interface is immaterial.  Both result in the same pain – mixed concepts (see plumbing above).  Annotations should be specific to the business such as @RecalculateCostsOnRerouteOfCargo can be used as an interception point for injecting a rule on a class or method.

I would go even further and say that the POJO JavaBean specification is also broken.  Why on earth must I have a no-argument constructor and accessors and mutators.

Last thoughts …

I may have missed some of the other discussions but these are the ones that I woke up with this morning. In general, my observation is that we need to be very concrete very early if we want to be agile, even in architecture.

Metaphors may be a good way of getting to grips with a new domain.  It allows you to imagine the behavior of something that you don’t quite understand (yet) in terms of something with which you are quite familiar.  That’s were it should stop. I hate metaphors that extend beyond their purpose.  Once I have a good enough understanding, I drop the metaphor.  My reason is simple.  Metaphors force me to do a lot of energy sapping context switching.

Technical debt is one of those metaphors that have been extended so far, that it is believed by many to be something tangible.  Let’s get real here:  Technical debt does not exist.  It is just a metaphor for us to realise that our code base may cost us more money than it should, and that is a future view.  Sometimes our metaphors become euphemisms, and then it is dangerous.  When it comes to technical debt, the less I think of code problems as debt the more I am able to face the problems head on.

Ironically, I did a talk recently on dealing with technical debt.  My fundamental position is simple.  Either your code base has things that exist as a result of broken principles or it does not.  The more principles you break, the more potential problems you have in your code. It is not a problem right now, but it may be a problem in the future.  This future can be a minute away when I run my next test or a year away.  If the future is infinitely far away, then it is not a problem at all.

My first prize is to not break principles, so I don’t create potential problems.  My second prize is to deal with real problems and just leave the potential problems for the future.

(Warning: I’m drifting into my enlightenment self-reflection, so feel free to stop reading now.)

If I am part of the exploration that is looking for a solution (living in the moment and not outside it as an observer), then I should be aware of principles that I am breaking and I should change course immediately.  If I am part of the exploration that is dealing with the potential problem that is now a real problem, than I need to understand the principle that was broken and fix the problem by restoring the principle.  Restoring the principle could mean going on a search for the right solution to the original problem, not just trying to fix the problem that is a result of breaking a principle.  This problem that broke the principle may just be the wrong solution that we thought was the right solution because we ignored our principles in the first place.

Hmmm, that’s an interesting thought.  Karen Greaves asked me if a re-write can be justified and I mumbled something about technology, etc.  What tripe!  Now I think I’ve just reflected on when a rewrite is justified.  When refactoring will not fix the broken principle, then the right solution was never discovered in the first instance.  That is also what I mean when I say that clean code is necessary by not sufficient.  At factor10, we call this a radical makeover.  Radical makeovers are a viable way of getting rid of real problems, and restoring principles.

Heck!  This blog post is less about technical debt metaphors than I thought.  Oh well, the ride on this journey never stops.

By the way, a huge thank you to Steve for helping me realise that all problems come from breaking principles, in code and in life.

Next week, I will give a talk at the JCSE Architecture Forum entitled Architecture in an Agile World (or maybe it’s the other way around). It’s not a new topic but since I visited it at a MagmaTec conference late last year, I have updated my thoughts a bit.  The angle is also different because I want to explore what it means to be agile in process, and agile in practice and how that relates to understanding a problem and carving out solutions.  Often, it is actually a choice to find a solution that is just and that is able to balance the various tensions.

But, I think I am equally excited at the possibility of seeing some familiar faces again in Johannesburg.

Do you remember that catchy Beatles song?

Oh yeah, I´ll tell you something
I think you'll understand
When I say that something
I wanna hold your hand
I wanna hold your hand
I wanna hold your hand

So what made me think about this?  That frustrating construction of the new M5/N1 interchange in Cape Town!!  When you’re sitting in traffic, you can’t do anything but look and think.  And I’ve seen this scaffolding get taller and taller and wider and wider and longer and longer and more and more people appear on it each day.

Sourced from http://www.capetown.gov.za

I know that one day, they will remove the scaffolding and the concrete will just hang there in mid air on those massive pillars and walls that they’re busy building, and I won’t be sitting in traffic any longer, and it will all just work.

What a shame that software is not like that !!  So many people get turned on by scaffolding.  And The Beatles sang on …

And when I touch you i feel happy, inside
It's such a feeling
That my love
I can't hide
I can't hide
I can't hide

And just like the M5 construction, so much scaffolding gets built, and so many people climb on.  But then, they don’t climb down.  And they don’t tear down the scaffolding.  And it just stays there mashed in with the concrete bits.  And then they ask people to use it.  And it takes strain and then it’s a performance problem, or a load problem, or it just crashes down.

I do use scaffolding, but most of the time it’s in a spike and more often it’s in a test, just to get me over my point of fear.  Deploying software with scaffolding is just dangerous and negligent.  I really don’t want to drive my car over the M5 interchange while those thin steel pipes are holding up the concrete slabs.

But above all of that, the most important scaffolding is social scaffolding.  It’s better to provide human scaffolding to support each other on a team that is focused on delivering quality software.  It’s worse to plug in weak struts in the code base that will just collapse when the next developer builds on top of it.  Very un-ubuntu!

So, the Beatles song still holds true, but only for social scaffolding.

Yeah you, got that something
I think you'll understand
When I say that something
I wanna hold your hand
I wanna hold your hand
I wanna hold your hand
I wanna hold your ha-a-a-a-a-a-and

Most agile people say big designs up front rarely pay off.  You spend so much time doing design that you delay the opportunity of feedback from real, working software.  But I sometimes do BIG DUF.  It’s not that the design is big, it’s the problem that is big.  So I need an up front big picture with just a few big parts.

It helps me conquer and divide.

That’s not a bad thing.  What I find really painful is casting the design in concrete.  When your design is cast, then your mental state is already cast in concrete too.  And that means that it is a lot harder to do the right things.  So, more gets added to the concrete slab and it’s real hard work to break anything off.  When I have a BIG DUF, I often look at how to reduce it, rather than increase it.

I don’t think it’s wrong to have a  BIGDUF, it’s worse if you have a BIGDIC (BIG Design in Concrete).  That concrete block will hurt you later … a lot.

In other words, the size of a BIGDIC does not matter, it’s the rigidity that’s the problem (– That’s so lame, I could not resist!)