Thursday, December 11, 2014

My thoughts on the HATEOAS debate

So HATEOAS is a hot topic. The discussions is about whether if its a good way of actually using it for an API or it should be the API. There are several things that concerns me.

Firstly there's no programming model for HATEOAS, such a like functional programming, procedural or like SQL type. Its representing something which there are no other mechanics for, so why would it be suitable for APIs?

Secondly the so called APIs, with exposing resources, requires a client which is dynamic enough to actually understand all of that data, and simple links to describe their relations. I haven't yet seen a language which does this natively so why would HATEOAS do this? SQL is pretty good at expressing relations and linking it together, however it doesn't understand what it is. Why would HATEOAS be so much better?

If HATEOAS is all of what you need to describe an API, why do I need a network to make use of it. Why isn't there a way of using it like a language? When there's a way of coding it and expression it as logical relations, I'd say it's something worth looking at.

I think all of those who think they need HATEOAS to describe an API have no idea of how to make one, it's simple like that. Yes you can create something which resembles an API, because you are exposing something which an consumer could use for something. BUT that's still not an API, simply because an API is so much more than how you relate resources to each other.

Most of the time when I see arguments for HATEOAS is the ability to extend without changing the client. The problems with having to change code because you update your API is a technical problem, not a API problem.

If there's any out there which could present me with a HATEOAS client which doesn't contain any code at all (!) and is able to understand what it can do with the API the client is exposed to and does everything the API exposes in a comprehensive matter which is useful, then I'd start think HATEOAS is a good thing.

Thing is, if you cannot show that you don't need a client which you have to translate the resources into something useful, HATEOAS is just another way for hipsters to mess up APIs.

Some links to read more about it: Jeff KnuppMule Soft,API Evangelist

Sunday, November 16, 2014

Is REST the best thing there is?

This blog post is about what's important when creating an API. There are a few things which is sane, but there's a diagram which is, to be kind, misleading.
Requires a SOAP library on the end of the client
Tightly coupled
No library support needed, typically used over HTTP
Not strongly supported by all languages
Can return back any format although usually tightly coupled to the RPC type (i.e. JSON-RPC)
Returns data without exposing methods
Exposes operations/method calls
Requires user to know procedure names
Supports any content-type (XML and JSON used primarily)
Larger packets of data, XML format required
Specific parameters and order
Single resource for multiple actions
All calls sent through POST
Requires a separate URI/resource for each action/method
Typically uses explicit HTTP action Verbs (CRUD)
Can be stateless or stateful
Typically utilizes just GET/POST
Documentation can be supplemented with hypermedia
WSDL - Web Service Definitions
Requires extensive documentation
Most difficult for developers to use.
More difficult for developers to use
Easy for developers to get started
As for item (1) this is entirely true, but the item (3), is just blatantly false, we tend to keep forgetting that you need a library to use http.
Item (2) is not true, you are tightly coupled with the implementation of the RPC library (which you are in both SOAP and HTTP/REST) so whats the difference?
(4) is valid however a weak point. SOAP is basically XML+XML parser+XML validator and http client.
(5) is weird, what data isn't coupled to it self?
(6) This is myth with REST about exposing methods. So it matters what methods I use to make a call? Consider following code
public class MyResource {
    public String GET(String parameter){
          // return something
    public void POST(Map <String,String> data){
      // do something with data
    public void DELETE(String id){
       // delete id
    public void PUT(String id) {
       // update id
    // The rest here... All pun intended :)
So whats the difference here? Does a method name matter that much? You still need the URL just as you would anything else. This also applies to items (7) and (8).
(9) I must admit is convenient with REST, however still achievable with other means but a lot uglier so this I guess is a valid point. However in a real API this is a moot point.
(10) is true but in certain environments this is actually more loser coupling than a REST call, since you don't have to know content of the message but only that its a SOAP envelope. The envelope creates a loose coupling for some broker system since they doesn't need to know the type of message or the endpoint. Another important things is that if you use HATEOAS could actually result in more data sent because you have to manage the resource from the client, whereas if you use a SOAP this is managed by the server.
(11) if this a problem, then I guess you have larger problems.
(12) This just doesn't matter. In any large application this will be loads of URLs and confusing by its own.
(13) True, but a technical detail.
(14) Same as (12), just doesn't matter.
(15) If you build services as CRUDs then you are creating unmaintainable services/APIs.
(16) True but moot point.
(17) Again moot point.
(18) Again, there's no CRUDs. Code which based on this is automatically unmaintainable.
(19) True, but in there's WADL for Rest too. This is a nice feature which RPC usually lacks, however using a interface for RPC is not bad either.
(20) Wrong. You need as much as you need for a REST service. If you don't then you don't know how to code. Sorry partner. Just because you use REST doesn't remove the need of context of what the resource do, supposed to be and what relations it has. If you build you application on this premise it will be buggy and error prone with time. It will also add unnecessary costs to maintain it.
(21) This is just irrelevant point.
(22) Well if you have good tooling, I'd say SOAP is the easiest, though I can agree it could get unnecessary complex. I also think that SOAP is trying to do too much which is not needed.
(23) Again irrelevant point.
(24) Again with good tooling this could be as hard/easy as using SOAP.
(25) This depends on the RPC implementation. However its easy to hide it with abstractions.

A protocol is NOT an API. REST is a deceptive technique. If you have a web application and you want some sort of database without anything in between REST could be a choice. However if you want to do something else, use other everything else but REST. REST doesn't create an abstraction as it's advertised to do because the mechanics of retrieving and getting data is now on both sides of the protocol boundary. This creates a mechanic coupling, stuff knows too much about other stuff. I bet that we'll se a lot of "legacy" problems in the future where rest apps are becoming a real problem. There is a lot of problems with the REST proclamation and of its benefits. My view on that is that REST is the answer on another problem which is born out of inherit problems with the inability to code correctly (and that differs on programming paradigm, language and framework).

My point is that, it cannot and should not matter how you retrieve data, just that you actually did and what that meant for that particular code. If the protocol implies mechanics on meaning you are mixing things which should not be mixed.

Friday, November 14, 2014

So what is "decoupling"?

One favorite argument when arguing for new technology or when people is arguing over what design principles you should use is the term "decoupling". My personal belief about this word is that it's extremely abused and more than often just used to boost the credibility of your own idea. It's also used as something to give the technology some "magic" properties as in "if we use this everything will be a lot easier". This is especially true for the arguments for using technologies like REST or Microservices. These two definitely have their uses but too often they are used as some sort of silver bullet which solves everything you throw at them. And with these two technologies are very often accompanied with the term "decoupling" or more correctly loose coupling. Well how intriguing, so how do they do this?
Consider following code
public void process(String[] array){
   for(int i = 0 ; i < 3; i++) {
       // Do something with array[i]

So we loop through an array which is 3 elements long. So what happens if we do
public void process(String[] array){
   for(int i = 0 ; i < 5; i++) {
       // Do something with array[i]

We have now changed the loop to 5 iterations. We haven't changed the method's signature so we don't need to change the type or anything, in a REST service the URL haven't changed. It still looks like the method as in the previous example. However it will fail if the client only has provided an array which only contains three elements. So how does this relate with REST or Microservices? Well if this would be a REST method, the technique REST wouldn't do shit about it. It would fail miserably like any other protocol able to invoke a method. This change will require a change with the client, so its not particularly "decoupled". The same would be true for a Microservice, all of its clients has to change. So where's the decoupled stuff with it? In REST is it the idea of you could add parameters without changing an API with a JSON map? Whats the point of that, send in data the service doesn't use or receive data which is not used? Have a endpoint which swallows data which you then try to make sense of it? Yay now you just created a ball of mud service by bypassing all of the abstraction mechanics you have available because you are lazy and being unprofessional.

With a Microservice the argument is that just because you can deploy stuff separately will make them decoupled. How does that apply to the above change?

 There's no such thing as a free lunch when coding. The above code is extremely simple but the length of the array is extremely important for the overall functionality of that piece of code. Actually there loads of information you have to deal with just with dealing with a string array of 3 elements. Cutting corners here will create a code which is bound to be misunderstood (yes with or without test), its just a matter of time. The above code has no description or information on what type of strings which is allowed as parameters. String's per se is an abstraction of information. A standalone string doesn't mean anything, it has to be put in a context which is meaningful for that particular data type. Just because it's a string and it's "understood" by the java runtime as an typed object doesn't mean its something which is relevant.

In today's http world, where we don't have to deal with the underlaying binary behaviors because it's abstracted away from us by standards like UTF-8 and such its really easy to not understand that most of the things we are dealing with are just some sort of representation of something, but because we can read it, and interpret it (as humans) we forget that whenever we're sending stuff (changing context) the information has to checked again to actually make sure that the context hasn't changed. This is what we see in the above example. The context has changed. It's still the same type of data but the requirements has changed.

Yes the example is a simple one, but imagine when a system contains millions lines of code, and try to follow data through a system where the code is not describing it's expectations of data makes it extremely hard to reason about the outcome of that code. So think twice when using your damn maps, and just because you can give abstract properties to the relations of an object doesn't mean that will create better code. In fact it will create a lot worse code since the intentions of the data is not described. It's like you would convert everything into an the type object and typecast it just whenever you want the information.

Monday, November 10, 2014

The meaning of pragmatic

On the net there are an abundance of advice how you should be doing this and that to actually be successful in delivering projects. You should be agile and develop agile systems but no idea on what agile code is (no it's not writing tests all over the place). You should adopt this or that work flow/process/mantra/technique/<insert the buzzword of the month here> and you should use <insert the programming language of the month here> and by using <insert the flavor of architecture of the month here>. Oh shut up and pick a language and use that. Swapping between languages for solving things is not a good thing. You don't see a lot of professors in several languages for a reason, its just too hard (of course there are a few which is good at it, but thats a few.). Problem is that it's very hard to define someone as really good at a language, how do you measure it?

And also that everyone is pragmatic by doing simple things in a simple way.
WTF...? If coding is simple and solving problems is simple why do we have a job and is a problem a problem if its simple? No wonder that things fails and code looks like shit. A newsflash for most people, if you code is simple like a CRUD, you just failed programming 101. There's no such thing as a free lunch, particular when writing code. There are frameworks which will make you life a bit easier but, most of the time they fall short. Also if you are coding you ALWAYS have to look at the big picture (yes TDD falls short here). If you don't you will end up with a piece of unmaintainable piece of crap code because it's content is just rubbish. It may look all "clean codeish" and dandy with tests and stuff but it will still be a piece of crap, and bug ridden.

Oh hell, I just wrote my own "advice" (read rant) on the net... So I'll give my opinion on what pragmatic means. Pragmatic is NOT: use small frameworks and simple code.
Pragmatic is: use frameworks that are known and write code which makes problem solving simple.

Sunday, November 2, 2014

EA is troublesome

This blog post is about 6 heresies you could do with EA. And in my opinion, this is why EA fails because its too slow to actually do something useful. In any system which EA is needed the details are hard to capture with EA and its tools are too abstract. The post also says that EA practitioners usually fall in love with their framework so much that it becomes framework produced model which is not modeling the system its supposed to model and they should develop something that "works" for them.

It would be nice to have some framework to reason about the system, problem is that how the functionality of the system is in the details of where the code is executed. Usually the models of a system is bound to the physical structure of the system and also that a process forms a module. This is just not simply true, but to know that you have to dig into the code where there are several details which makes out the functionality. There are things like language constructs, code constructs and lack of information which is crucial for the model, but that is only found in how the code is built. And unless we are able to figure that out each time we take a "snapshot" of the system, EA and the tooling will fall short.

For EA to work it has to be a lot more code centric, and it's tools needs to be able to understand code and what its built for, and unless that is not figured out EA will not to able to provide information which could be based on making decisions. I'd say because of this EA is responsible to actually make systems worse because you are not able to make decisions which is reflected by the code but the process instances, which is not good.

There are several other issues with EA related to the inflation of patterns, but thats another post.

Edit: A good view is this video. Simon Brown has a good things going on there.

Tuesday, October 14, 2014

Are you solving problems by solving it with new technology?

Talked recently with a old colleague of mine about the solutions we are working with. We both worked with legacy and green field projects together and now he's tearing several old Tomcat systems apart and creating smaller (but not Microservices) services. He's using Dropwizard and this is a particular cool platform and I was eager to hear about it. My current assignment is working with a couple decade old JEE applications which has been somewhat ported to JBoss (which for the record, has not been impressive as a platform). But what we had in common on our new jobs were the fact that we had to take care of loads of legacy code. Both systems are lifting a heavy load and serving millions of transactions each day, and one system is from a successful startup.

There were two conclusions we made:

The first is that it really doesn't matter what you try, your code will look like crap or at least the guy coming after you will think of it does. Even the best intentions of keeping it nice and neat, if not given time or its large enough, it will deteriorate into a ball of mud. Both applications has been "customer" driven and whenever something major has changed, the developers hasn't been given the time to do a proper rewrite. For different reasons even the rewrites is not optimal and probably is the result of the second conclusion.

The second conclusion is that, for some reason people tend to solve problems by throwing technologies at it, like a NoSQL database or some fancy framework instead of just using plain old code. Whenever they are trying to solve stuff with the "new cool tool" they might solve the immediate problem, but loads of others problems turns up. Part of it that the developers doesn't understand how to use it or its just too damn hard using it, or its not working as they thought it would be. Or they end up with different frameworks entangled, both not fully understood or adapted.

I think we all have been guilty of being the one throwing "that new cool tech" or pattern at a problem instead of actually solving it with the current choice of technology. Every time someone starts blabbering about patterns, and particular when I know they even haven't understood the implications or details of that "pattern", I can almost feel the deterioration of that particular code. Or when you incorporate that, on the paper, beautiful BPM or <insert architect's new favorite tech solution which he have studied but never used> which you really don't need and poorly understood, because the only thing you need is code. And this is also one key factors which adds to crap code, is the idea of buying some other thing which should be able to "fix" the mess your code is, instead of just writing proper code.

On the other hand, as a developer you automatically assume that the guy which touched this before you is a dumb redneck which fell asleep on the keyboard which he have happened to pass on his way to the toilet. As the Dilbert strip so eloquently pictures it, do we as a professional admit the last guy actually did a good job? I know I've been guilty of thinking in those terms, but lets face it, most people does these things to put food on their table, not building the most beautiful piece of code ever existed.

I think most of the time you just need to sit down and think hard on what you could do with your current solution can do for solving it and not being seduced into using some technology.

Wednesday, September 17, 2014

Why you SHOULD use layered architecture

This post argues against using layered architecture since according to the post you simply don't change implementation of your database or implementation of JPA.

Firstly, the term layering is a misused term, layered architecture should be regarded as layered on its own. There are several different layers, such as communication, framework, hardware each of these might contain several other layers of multiple layers of some notion, such as a OS hosting processes etc. Layering is a code standpoint when you choose the "what" of all of the combined layers and present functionality and why they matter to the layer above.

Now secondly, if layers matters, you are doing layers wrong (layering to hide implementation of frameworks in a application which is about e-commerce is silly). Layering is organizing context, a common misunderstanding is that layering are abstractions. It has a lot to do with abstractions and most of the times its get confused with it, but it really is about context relaying, where the details of a function effects the surrounding code and layers.

Context relaying is heavily bound to the fact that abstractions leak. Some sort of combined function will always leak the inherent functionality. If it were true that the function wouldn't leak, it has to be so general that it will accept anything and reply with precisely what you want, i.e the God Service.

Now computers are inherently stupid, they will do as exactly as told even if its wrong, as long you talk its language. Problem is that whenever you are producing code you mostly focus on the how not the what. As an example is the inherently problematic behavior when writing objects. You might name an object as Animal and when you read this it seems like a very sensible thing to name your object because it might have a place in the object community. However this is blatantly wrong because the notion of Animal doesn't mean anything unless you provide proper context which is described with code, either directly or indirectly. Try switch the name of that object to X4 and things starts to make less sense. In fact, try obfuscating the whole codebase and try to understand what is going on, and if you do you might be closer to a good layering structure.

Now a layer is where a bunch of objects are making sense regardless of other bunches of objects are doing, even if there seems to be some sort of dependency of them. The code has to be reflecting this, if more than one "bunch" of code is breaking layers you have done layering wrong. Object oriented programming and TDD may produce bad layering because you are only are regarding the object or the"unit". To get this correct you have to focus on context and behaviour while creating the object and "unit". Both SOLID and the principle behind TDD encourages doing layering correctly if you focus on context and behaviour, combine them with context relaying you are one step closer to doing layering correctly.

Another factor of the "mess of layers" is the misuse of interfaces. And this is inherited by the fact that  its simple to produce code interfaces but hard to create data interfaces and those are mostly overlooked. Such as when creating simple CRUDs.

The idea of managing code with organizational structures

Recently Mckinsey published an article about how to achieving success in large complex software projects and their conclusion is cross-functional team produce better results. They mention an example of an insurer which had problems and switched to cross-functional teams. This let the individual programmers started to "focus on delivering end-to-end functionality rather than just thinking about their own roles" and because of this it communication improved, resolving requirements and solved problems faster. As a result code defects fell by 45% and 20% faster time to market.

The report mentions "agile, lean and test-driven" and shorter iterations but not exact methodology, but they do confine the development process into a team per module, whatever a module is defined as. Which should be aligned with having a cross-functional team.

However there are no, as usual, no mention of how the code were written, language used, just that you have to manage people and it will auto magically be a success. I think this mentality is really weird and typical for this kind of research. Also the example seems to be a new product which is defined from scratch, which means that most of the "bumps" is avoided (a legacy system is not documented and/or requires changes, rebuilding stuff because they didn't thought of your project when building things). As a conclusion, how you write the code really doesn't matter for your projects success as long they are producing functionality which the customer wants, and present belief, continuously asking the customer seems the way to go.

The claim that structuring your team which maps to the produced "modules" is interesting. Conway's law dictates that any system is doomed to be a direct copy of your organization. This has been dubbed to the Mirror thesis and the result is quite interesting. According to this, and somewhat Mckinsey, structure in the organisation should be reflected in the system. Two organizations which has taken this to an extreme is Avanza and Netflix. Avanza has apparently taken the scrum idea into the organization and utilizes it all the way up to the company board. Netflix tried to reverse Conway's law by implementing microservices and structure their organization from which architecture they wanted.

So if this is true having an agile organisation should produce an agile system. This should also be reflected in the code since the code outlines the system. So the thought here is that, in any given code base one should be able to get which type of organizational structure were used when building the software. Now if this is mirrored accordingly to which modules are produced which is probably fine, however if the modules starts to blend (more and more interdependencies between the modules, business grows, initial structure was off etc) with each other, or worse, the organization or business changes, due to external factors.

Now things tend to break apart, sometimes because its not feasible to change the codebase because theres no time or its not just understood. It might be so, combining information in new ways creates new interesting business areas which breaks old module "barriers". Management has no idea that a decision completely wrecks a structure, or system is simple not able to deal with the modular idea. Either way there's no way of escaping Conway's law, even with all the good intentions in the beginning.

But using an agile organization or development process (which is part of the organization) the code should be reflecting this somehow. The only evidence I can see is that TDD could produce "test induced design damage" which happens when testability becomes the main goal, and is not a good thing. The result will and always will be a result of your organizations communication "routes" since that what systems are all about, automatization of whatever case you have, and any deviation from that will cause an mismatch in your total organization and will create tearing problems.

Tuesday, June 24, 2014

Microservices - a code problem solved by making it a CM problem.

Microservices is really a buzzword, as in "if you look up the word "buzzword" the explaination is "microservice"". It's a code encapsulation problem solved by making it a CM, which is really just another problem and really not a solution since CM cannot solve code problems since it's not what CM does. It's like saying that REST is a service and not a protocol, because if that's was true you wouldn't need any code implementing the service... eh resource exposer. It's like if you said "honey, could you take out the trash?" in Swahili but it really meant "the weather in north east will be rain" just because you said it in Swahili.

If any starts talking about REST is the shit for solving all your problems, or how you deal with versioning, be afraid... Very afraid.

P.S if anyone starts talks about API management with some product doing that, run... It's ok if you scream too D.S

Tuesday, June 17, 2014

Enterprise architecture is fine but redundant

Using EA for describing your business or how your system work is a hazardous thing to do. You can't use EA or any of the modeling concepts EA use because the code is dictating the result. And because the rapid change of code, EA is doomed since it is not modeling the truth any more. Besides a line of code could change the whole EA map and if you don't know where to look you cannot make any decisions about your system. Because how the system is built and where the relative location of the code and the function it represents resides in a system matters this is what you have to track to make sure that your system is even close the the EA model.

Making decisions from a EA model is extremely risky, as I've seen this bring down CIOs just purely because no one checked or understood the importance of the code. Simply modeling part of a system as an entity of a system is not enough and making decisions from this is, most of the time, fatal. If you have bought a system which does the a specific thing, for example a database or system which keeps information about your customers, you cannot treat them as a black box. As soon you do this, the rest of the system is screwed, and particularly each change to this system is doomed to increase costs exponentially. The location of the functions of the system is extremely important but to actually know if a system is an entity you have to look at the code.

The paradox of a system is that if you don't know what the code looks like and get the context of the functionality you won't be able to make decisions about the system. And that means if you cannot look the code you cannot make those decisions. Even if your treat a part of the system as a black box you still have to know how the code is aligned and where the functional chunks of the code is populated to make the right decisions.

The reasons for EA is a bad thing is the thing it tries to solve is in the details of the code and as long those aren't considered your EA map won't be a good baseline to make decisions. If you have architects which are never even close to the code they will supply you with bad intelligence and a decoupled view of your system. And they will cause the system to deteriorate into a system which is extremely expensive to maintain or change.

Friday, June 6, 2014

It's damn hard to write software

It's damn hard to write software. There are too many variables to track for writing good and successful product. Even the notion of product is different, sometimes it means a new product from scratch sometimes it's a redefined product, perhaps a product which is split into other products. Sometimes the product you are building is the wrong product, or based on something assumed being right but was the wrong choice. Perhaps the product is so old there is no way of tweaking/building/repairing it so it will be a good product but the customer is too afraid/blind/have no idea/clueless/careless/reckless/"hopefully-you-can-fix-it" to acknowledge that. Sometimes there will be some business case describing some fantasy world where the ability of changing the system is either estimated by an ant or the business haven't even taken things into account that there are a system actually doing the work here. Sometimes you have customers you can ask if you are creating the thing they want, sometimes there are no customers to ask, sometimes the customers doesn't even know what they want, or understand what they need or understand what they are getting. Sometimes the customer is some other system and the true customer has no idea what that system does or even do.

You have project managers which have no idea how to do the things you are doing and how important it is to make sure you are able to do what needs to be done. The same project managers only speak timelines and resources, understanding only the next release and only half understanding the customer or stakeholders. Project leaders with no technical knowledge make decisions they cannot even comprehend since they don't know how to code or they haven't event looked at the code. Most of the project leaders are either strictly religious to some belief of process and/or have minions which notoriously upheld sit, or you have the psychopath which does everything by his or her book, no matter what.

You have architects which are, most probably, the only ones in the whole system which are decoupled, and with reality. They do talk about decoupling and systems but have no idea if it's actually true because they are not in development. They draw fancy diagrams about things which should be like how things should be but they are not even close, so they are just doing drawing things. You have some architects which have no idea what your system really does but still comes up with solutions which just messes thing up more. You have enterprise architects which are even more remotely from the system but dreams up some  un achievable goal, aiming for the stars but satisfied if you end up in the tree tops. Problems are both the goal and the material the goal is decided upon is not even close to the reality since they are not even close to the action. There are also strong religious beliefs making up their decisions because of that (*cough* REST).

You have management which only thinks of their next promotion, and thus they just need to make decisions which are just enough so it will look good to their management. The management just over your management makes descisions about things they cannot make since the information about which decision they should do are in the code. They most often have no idea that they are not in charge anymore since every decision is ruled by your system. It really doesn't matter what the management wants, it's the system which has to be convinced.

You have developers which just want to go home for the day, bored at work, disgruntled. You have developers which want do a perfect job but there are no time. You have developers which doesn't understand what they are doing or why. They don't understand the current technology they are using or language. They are swapping between different languages which makes their code less efficient because it's hard enough with context switching as it is. You have developers which works best in a closed room but they are out with everyone else. You have developers that doesn't talk, doesn't share or even care. There are developers with beliefs they cannot prove, they have beliefs which are true to them but irrelevant to everyone else. They are developers which believe what they are doing is art, and in that case everything that applies artistry should apply to their coding and because of that flame wars starts and things turns ugly.

Then there are the system which hosts the products. If you are lucky there are no previous system and you are building it, but then you probably have to deal with politics and religious flamewars. Otherwise you have to wade through bad decisions, all those quick fixes which bleeds the system until the system is no more than duck tape, because some managers just didn't have the balls to do the right thing. You have to write code with technology which is either outdated or not suitable for the things you try to do. You have to integrate with a system which some suit have bought because he believed the sales guy that sold the system to him, and it turns out it doesn't do what he suit thought he needed or it doesn't work with your current tech stack and somehow your competence suddenly is at stake. You have to integrate with a system which is outdated and even if you applies every tech known to man to make it scale it won't. Or you have to deal with some tech consultant which has "the new next super tech which solves all your previous and new problems" and it still won't fit in with the current technology.

Luckily none of this have happened to me.

Tuesday, June 3, 2014

SOA is most probably dead at your company.

There are many ways of implementing SOA, now latest buzz word for example is micro services. Many are using some sort of enterprise bus, some says that REST is the way of implementing SOA. Problem is that neither is enough for being even capable of being SOA. It's because they are only dealing with protocols, and protocols are never services and when talking about services the means by reaching it, even REST(whatever flavor) cannot act or even be a service. Even some notation of not using services, whatever that might be, like just wrapping data to JSON, is begging for trouble.

If your goal is to write a sustainable, maintainable and flexible system it will never be about what protocols you are using. It will never be about which application server you are using, or if you are using micro services and particularly never if you are using an enterprise bus, or using some sort event driven distribution. It will and will always be about when you are doing transformations.

Now for example you are using a enterprise service bus with an application server you have failed to being even remotely close to deliver a SOA system. This is because you are not keeping track of your transformations, and fundamentally spread your functionality over several abstraction layers, just by using an ESB. Are you trying to aggregate other services with an ESB you are still creating stronger coupling by just using it because you are not adhering to those interfaces which are defined by either service/resource.

You have just begun your journey to a incredibly much more expensive development, much more entangled system and not creating a flexible system. Everything else is just sales talk. The only way of creating a flexible system is by WRITING it in a way so it won't entangle into a big ball of mud. No external system will or cannot fix anything just by adding it as some additional layer. It will look perfectly good in the simplest cases, particular in a PoC, but in all scenarios and over time you will end up with a more complex solution which will create a less flexible solution as you would without it. If you are using a product for "managing" your API's (WSDL's) or anything which describes your service, you are by just doing this, creating a non-flexible system, because you are not using your abstractions correctly. Using an ESB for anything else than translating a protocol to another protocol is abusing your abstractions and cause your system to turn into a ball of mud over time.

So why is it important to keep track of your transformations? We'll this is because this is where you are providing the interface for your data. But when doing this you must transform your functionality as well if you are going to use your abstractions correctly. Whenever you are transforming data 1:1 and there are some notion of functionality present, directly or indirectly, you are abusing your abstractions and creating a worse system. Which is ALWAYS the case when using an ESB with an application server, other than when transforming from one protocol to another (and that's only because you have no other choice because the application server doesn't understand the protocol).

I don't know when it became some sort of standard when protocols became services. Protocols to me is how you talk to a service, by such means, you could talk about decoupling, ie you have decoupled how you would talk to the service. But a protocol cannot decouple the service from the client since the protocol is not the service, thus the contextual meaning of whatever data you receives from the service cannot be decoupled. The only thing you can decouple from the client is theimplementation of the service. But that will not be done simply by putting a WSDL infront of the service. This also applies to REST, since this is just a protocol a swell, a means of how to reach your resources whatever they be. However the service still needs to define what the resource means. And that will never be done by the protocol.

Sunday, February 23, 2014

Software industry

There's something wrong in the software industry. To me it almost looks like when someone comes up with a new religion and there are several people coming up with ideas how to please the new deity. Schools or profets emerges trying to teach the "right" way of pleasing the deity, although in software industry it seems like original focus of deity has emerged into a second more profane deity, the "customer". A number of different rituals are cooked up to mask the fact that they are either not knowing what they are doing or add more scenery to the process to mystify their work or it's some combination of both. It almost looks like a scene from Monty Python's Life of Brian.

All these different "schamantic"(if we do it according to this process, the project will be a success) processes modeling seems to forget the underlying system. It's like if programming is not the issue while building software. Even TDD is not a guarantee that your project is a success and that's a process which at least have something to do with the code. None of the processes are really considering the system and how the system will react to those processes. I've seen Scrum based processes break down since the system doesn't adhere to the principals of Scrum, and no matter what you won't be able to fit in any sort of iterative process in those systems.

As an example is to have three components, A, B and C which depends on each other and a change is affecting all three systems. Now the quirk, system C only has one guy who knows how to code it. Add to it that there are several changes needed to be done at the same time, and things starts to break down. It almost looks like a thread deadlock.

Most of today's processes may it be lean or anything else, forgets the system and what it needs to function accordingly. It's pretty naive to believe that every part of a system could be developed according to some process which is applied throughout the whole development. The most scaring part is that the belief is that the more process buzz words you are using the better chances there are you are succeeding with your project. The system will act as any other employee and needs to be governed. And as human, we react differently to management as a system would.

I think there's a belief that management is ruling systems but it's just the opposite. The system, large and old enough will manage you and there's no way of dealing with that other the way the system is built. If you want system to be governed by an agile strategy, it has to be build as an agile system. But just because you build a system with agile methods it doesn't mean it will be an agile system.