“Design Patterns” 15th Anniversary

October 26th, 2009  |  Published in book, commentary, patterns  |  Bookmark on

It’s been 15 years since the publication of the seminal Gang of Four Design Patterns book. Since I was a reviewer of the original manuscript and also have a quote on the back cover of the book, the publisher recently asked me if I would write my thoughts about how I view the book today and how I think it’s affected software development over the past 15 years. You can find my essay along with essays by Linda Rising and Josh Bloch on the 15th anniversary web page for the book. There’s also an interview with the authors linked there, which I found interesting in part because of the similarity between what the authors say about patterns and functional languages and what I wrote in my essay on the same topic.

You Have to Experience It

August 16th, 2008  |  Published in commentary, erlang, productivity, REST, WS-*  |  Bookmark on

I’ve noticed that frequently in technical discussions, the strongest disagreements seem to come from people with little to no actual experience with the technology they’re arguing against. How can that be? For example:

  • Test-First Development. I wish I had a dollar for every time I’ve suggested to a developer that writing their tests before or along with writing their code will make the code not only easier to write but also more robust coming out of the gate, and I get back responses like, “What? That’s crazy! How can you write tests before you have any code? That doesn’t make any sense!” Having an initial reaction like that isn’t such a big deal, as I’ve seen numerous developers who have such reactions actually try the “test first” approach and quickly become strong advocates who wonder how they ever did without it. The point is, though, that they actually tried it. Arguing with them before they tried it always turned out to be a total waste of time. No amount of words seemed to convince them. They had to experience it before they understood it.

  • Erlang syntax. Erlang is getting more and more attention these days, and rightfully so, but a typical reaction from those who have written little to no Erlang code is that the language’s syntax is too weird, too hard to read and write, etc. Is the syntax different? Yes. Is it weird or difficult? No, not at all — in fact, it’s actually very simple and regular when compared to popular general-purpose imperative languages. Spend a day or two writing some real Erlang code, and I guarantee you that any initial dislike you might have for its syntax will disappear.

  • REST. If you search the blog of any REST proponent, including this one, you’re sure to find all kinds of comments from detractors who argue against REST despite never having used it to develop any real systems. Similarly, the blogs of many WS-* advocates who have never tried using REST contain all kinds of reasons why REST can’t possibly work. Check out the comments in Damien Katz’s recent “REST, I just don’t get it” posting, for example; you have useful ones from those who have obviously used REST and understand its benefits, and then you have other comments that argue against REST while simultaneously showing a great misunderstanding of it. Those detractors would do well to read Bill de h├ôra’s excellent response.

Also interesting about these three particular cases is that I don’t personally know of anyone who’s actually tried the approaches and decided against them. In a posting last November, for example, I asked for comments from anyone who had actually tried REST for real and with an open mind, but decided that it was inferior to WS-* and so abandoned it. Either nobody read that posting or no such people exist. I’m fairly confident it’s the latter.

There will always be arguments made by people whose livelihood is somehow threatened by the approach they’re opposing, but I don’t think that’s the source of all the opposing arguments. As developers we can’t possibly try everything, of course, because there just isn’t enough time. It’s inevitable that we’ll sometimes have to resort to researching an approach via only reading, questions and discussion and decide against it without prototyping. But ultimately we developers owe it to ourselves and our employers to keep ourselves objectively informed so that we can take advantage of new approaches whenever appropriate. When a whole bunch of smart developers have success with a particular approach, I don’t see how any responsible developer can actively and vocally oppose it without first objectively trying the approach and experiencing it firsthand.

SOA Elitism

July 7th, 2008  |  Published in column, commentary, review  |  Bookmark on

As an author I don’t expect everyone to like what I write or agree with everything I write. I’m always up for receiving constructive criticism, as it helps me improve my writing, and when carried out with a positive mindset I think it helps everyone involved in the dialogue learn something.

Unfortunately, not all reviews are constructive, and those that aren’t can be hard to handle. I don’t know why some people have to resort to name calling and harsh words if they have a technical disagreement with you; perhaps those folks lack emotional fortitude and feel big when they hide behind their blogs or email, or maybe they don’t realize how foolish their own words make them look. If you’re an author faced with such a review, do you sink to the level of the reviewer and fire back at them with harsh words of your own to try to put them in their place? Probably not, since that just makes you too look like a jackass. Do you just ignore them? Sometimes that’s the way to go, as you don’t want to encourage your new-found stalker to continue stalking you and getting off on having succeeded at trolling to gain attention. (I use the term “stalker” here because there are definitely people out there who seem to just sit and wait for you to publish something, anything, so they can immediately “review” it to prove to the world just what an idiot you are.) But sometimes ignoring the review is wrong, too, as it might make it seem as though you have no answers for the reviewer’s criticisms.

Steve Jones just published such a gray-area review of my “Convenience Over Correctness” column. I don’t know him but he’s apparently a dyed-in-the-wool SOA fan, so it’s totally unsurprising that he disagrees with me. I started to go through his review paragraph by paragraph and respond to each point, but I found that it wasn’t very productive, mainly due to the personal insults and attacks he decided to throw in, oh, every fourth line or so. I’ll therefore just look at three of his criticisms in response, and leave it at that.

First, Steve chides me for pointing out what he deems to be obvious:

So far these problems [with RPC-based systems] have been detailed [in the column] as

  • Remote calls have more issues than local ones
  • Remote transaction processing is a bitch

There are no other issues raised and both of these points fall into the “well duh” school of pointing out the obvious.

But then he says:

I’ve built distributed systems and I’ve had to manage teams who delivered the architectures I created and I’ll say that

  • 60% of the people didn’t understand the challenges and wouldn’t have understood Waldo
  • 30% would have read it and got it wrong
  • 6% Understand the challenges and can make a decent crack at it with minor problems
  • 4% actually understand what it takes

These two sections seem contradictory. How can Steve fault me for “pointing out the obvious” when by his own estimate only 4% of my audience actually understands the issues?

I know for a fact from my columns and my conference presentations that there is a great desire for this sort of information, and that not everyone truly understands the hard issues of distributed computing, so at least Steve and I agree on that. My preference, though, is to help provide that information and help raise awareness, whereas Steve’s seems to be to just assume everyone else is a “muppet,” thus enabling him and his other 4% friends to do all the heavy lifting and spoon-feed everyone else with simple frameworks they might, just might mind you, be able to understand.

This is elitism, pure and simple, and it’s an expensive and non-scalable model. It puts the self-proclaimed 4% experts in control and wastes the vast skills and talents of the majority.

Coincidentally, my September/October column is going to touch on this. It’s already partially written and is due in a few days, and while it’s not at all a response to Steve’s review, it will explain in part why elitist systems simply cannot, and do not, last. I’m sure Steve will completely hate it.

Then there’s this:

What a load of crap. Seriously this is an unmitigated pile of tripe in what it means to write distributed systems. It makes two basic errors

  1. That the architecture and design of a system is focused on a programming language
  2. See number 1

Ignoring the foul language and such, how can anyone claim to be an expert in real-world distributed systems development like Steve does, yet apparently be unaware of the various Java and C# systems out there, for example, that use special meta-language annotations to export and expose language features directly as distributed system features? There are many out there who think you just throw some annotations on a class and it magically becomes distributed — they think only within the confines of their language, and magic frameworks provided by the 4% experts like Steve make all the distribution work under the covers. (Steve claims this approach is necessary because it’s all that the other 96% are capable of understanding, but IMO it’s really just one of the ways the big vendors and big consultants can continue to relieve uninformed enterprisey companies of their money.) Criticizing the column on this basis simply shows that Steve, a self-proclaimed expert, is unaware of the language-specific distribution frameworks out there, which is odd given that they’ve been proliferating for years.

The only other particular issue I’ll remark on in Steve’s review is his idea that he could quickly cobble together some code in his blog to “prove” that RESTful systems can fit in a programming language, and thus also suffer from the “convenience over correctness” problem. The column already states that people are trying to do just that, but that from what I’ve seen they invariably run into problems with various REST constraints such as the hypermedia constraint. If it were so easy, Steve, we’d already be overrun with RESTful language frameworks. Thankfully, though, we’re not, because the two simply don’t mix conveniently, which is why I’ll continue to stand by what I wrote.

For many years I lived in the same enterprisey SOA world as Steve, and so the only positive thing I got out of his review was a reminder of how glad I am to be away from it. I met a lot of bright people there, don’t get me wrong, but I miss neither the elitism nor the “that will neither work nor scale within the enterprise, you complete muppet!” attitude that was doled out when anyone dared make a suggestion that might actually improve things or threaten the control held by those elite 4%. Thankfully, though, that culture can’t last forever.

But then again, what do I know? I’m just one of the 96% muppets.

Just What We Need: Another RPC Package

May 22nd, 2008  |  Published in commentary, distributed systems, IDL, integration, RPC, SOAP, WSDL  |  Bookmark on

I see from this CIO Magazine article that Cisco is releasing a new client/server messaging system called Etch. Sigh — those who don’t know history are indeed doomed to repeat it. Some choice quotes from the article:

This week Cisco Systems announced a new messaging protocol intended to allow developers to integrate client/server applications without the overhead of traditional protocols such as SOAP.

I was unaware that SOAP had become “traditional.”

One of its design goals was to create an inter-application communications technology without SOAP’s complexity and overhead, explained Marascio. While SOAP relies on a very complicated WSDL file to define the interface between the client and server, Etch uses a file in Cisco’s own interface definition language that shares many similarities to a Java interface file.

I bet this new IDL is not only simpler than WSDL, but it probably also avoids all the impedance mismatch problems that invariably occur when mapping IDL to programming languages.

In addition to a simplified configuration, Etch also promises less overhead over the wire, compared to SOAP. In a testbed environment where SOAP was managing around 900 calls a second, Etch generated more than 50,000 messages in a one-way mode, and 15,000 transactions with a full round-trip, company officials stated.

Oh good, the “performance presumption.” So now we’re back to where we were a decade ago, at least as far as message transfer rates go. I wonder if Etch also solves the problem that the bottlenecks usually lie elsewhere?

The Etch integration into Visual Studio and Eclipse will be very familiar to anyone who has used SOAP integration tools. After authoring the IDL definition, the developer tells the IDE to generate either a client stub or a server skeleton. The client stub is usable immediately; the developer needs only to configure the transport and endpoint, and to code the message calls.

On the server, the developer takes the skeleton and implements the business logic that lives inside the message handlers.

Now that’s what I call innovation!

Projects implementing their communications using Etch aren’t out of luck if they need to interoperate with SOAP, JSON, REST or other existing protocols. Cisco has already demonstrated the capability to easily create bridges between Etch and SOAP, according to Marascio. He said that turnkey bridges to SOAP and REST should be available six to nine months after the release of Etch.

Or, to put it another way: Etch is really just adding more stuff to be developed, tested, deployed, managed, maintained, and integrated, yet it doesn’t actually solve any new problems or solve any old problems better than what already exists.

Cisco also is examining the possibility of establishing Etch as a standard. Marascio pointed out that Cisco is well represented in the IETF, the main standards body for Internet protocols. Alternatively, Cisco might attempt to promote Etch as an industry standard, an effort that would be aided by Etch’s open source nature.

Well of course you want to standardize it — where would any new NIH RPC protocol be without an accompanying standards effort? Rather than the IETF, though, perhaps you ought to get those ISO OOXML guys to rubber-stamp it?

I find it hard to believe that in 2008 people are still inventing stuff like this. Sheesh. Color me underwhelmed.

Clearly Time To End This

May 18th, 2008  |  Published in commentary, distributed systems, erlang, reliability  |  Bookmark on

A technical discussion stops being a vehicle for learning when the following start to occur:

  • Someone starts making stuff up.
  • Instead of answering questions put to them, someone starts pointing out “flaws” in the questions themselves.
  • One challenges the other to some sort of programming contest.
  • Name calling.

The first two aren’t so bad, but when either of the latter two appears, it’s time to stop. Unfortunately, the third item has now entered my back-and-forth with Ted Neward. Since Ted has given me the last word, I’ll take it, but it’s clearly time to move on.

Given that a number of statements Ted’s made about Erlang in this discussion simply aren’t true, it’s quite clear Ted has never written any production Erlang code. [Update: Patrick Logan has posted a detailed analysis of Ted’s misunderstandings of Erlang.] Being a long-time author, it bothers me when people write authoritatively on topics they have no business writing about, so my only goal with my responses in this conversation has simply been to set the record straight with respect to Erlang. Ted originally said Erlang was a study in concurrency; I merely pointed out that it was more importantly a study in reliability. That’s really not even debatable. Unfortunately, it’s turned into a frustrating one-sided conversation because Ted lacks any detailed knowledge of Erlang, so he keeps unhelpfully trying to shift the focus elsewhere.

In his past two responses, Ted has picked at my questions like a grammar school English teacher, accusing me of conflating things, making bad assumptions, etc. I see that Patrick Logan is trying to clarify things, which might help. Yet Ted still hasn’t adequately explained why he’s taken such a hard stance against reliability being a fundamental feature of Erlang, nor how UNIX processes and Erlang processes are the same, as he keeps asserting, nor has he explained why he thinks it’s much, much harder to make an Erlang application manageable and monitorable than it is to build Erlang’s reliability into other systems like the JVM or Scala.

But now, we see the worst: the “programmer challenge.” Ugh. Thankfully, I’m sure most readers know that a programming contest of the sort Ted proposes would prove absolutely nothing. I guess he proposed it because I mentioned how I recently spent a quarter of a day making an Erlang application monitorable, in response to his continued claims that doing so is really hard, so now he wants to make a competition of it. I’d rather that you just explain, Ted, the experiences you’ve had that have led you to claim that Erlang applications can’t be easily managed or monitored. Better yet, since you’re the one who wants a contest, and given that you’re the one making all the claims, why don’t you go off and see how quickly you can build Erlang’s reliability into Scala and the JVM, since you claim it’s so simple?

If you’re a regular reader of Ted’s blog, you know that Ted generally offers good advice and you can learn useful things from him. He’s a good writer and a wonderful conference presenter, as he can make hard concepts easier to grok and generally does so with humor to keep you awake. But I feel that anyone in Ted’s position has a responsibility to avoid passing off incorrect information to his readers as fact. My advice therefore is simply that you don’t take what Ted says as gospel for this particular topic. Let me assure you that Erlang offers far, far more value than just exceptional concurrency support, which is where Ted’s initial posting in this thread seemed to want to limit it, and which is all I objected to. Unlike Ted, I’ve written quite a bit of Erlang code, and I use it every single day. If you write distributed systems, you owe it to yourself to explore Erlang’s capabilities and features. I’ve been writing and researching middleware and distributed systems for nearly 20 years now, and I’ve seen a lot over the years. Erlang is by far the most innovative and sound approach to distributed systems development I’ve ever seen and experienced — the trade-offs its designers chose are simply excellent. Like I’ve said numerous times over the past year, I really wish I’d found Erlang a decade ago, because I know for certain it would have saved my teams and me countless hours of development time.