dynamic languages


November 24th, 2007  |  Published in dynamic languages, organizations, productivity  |  Bookmark on Pinboard.in

Speaking of Reg Braithwaite, in this post he touches on team size and productivity. There are so many gems there, I could comment on just about every sentence, but I think this is my favorite:

If we know that bug per line of code remains amazingly constant, why do we try to scale code out in verbosity rather than up in abstraction?

I’ve very often wondered the same thing.

When I’ve given talks about dynamic languages and productivity, I’ve sometimes brought up the “bugs per line of code” constant. With dynamic languages, I generally write far fewer lines to solve the problem than I would in Java or C++. While that alone doesn’t guarantee correctness, of course, in my experience it sure seems to lead to solutions that are completed faster and with fewer bugs. Yet in those presentations, I’ve always gotten pushback on that idea from someone in the audience, typically based on the “static typing will save you” argument, which I’ve never fully understood despite having written, read, and fixed tons and tons of statically-typed code over the course of my career. First, the notion that you’re generally likely to have more bugs if you have more lines of code just seems like common sense, since there are just more chances to be wrong. Second, static typing does nothing to help ensure that you’re applying suitable algorithms and are correctly solving the problem, yet that’s where the bugs tend to be.

But it goes beyond bug counts — sometimes it even comes down to getting a solution vs. not getting one at all. The fact that you can quickly visualize and produce a solution in Python or Ruby, for example, means you’re a lot more willing to actually sit down and crank out that solution in just a few days, rather than agree to take on a multi-month multi-person task to try to drive that nail with a Java or C++ hammer. Not to abuse another cliché, but I truly have been there and done that, believe me.

Postings like these often seem to attract comments of the form, “Well, dynamic languages are just too dangerous; we have several hundred programmers and we can’t watch everything that every one of them does.” I think that’s precisely Reg’s point! But this also gets to another related issue, which is that if you build teams that you can’t or won’t trust, you’re simply creating a self-fulfilling prophecy. You’re essentially expecting your teams to fail, so they will. In that type of environment, you’re just not going to be able to attract or keep anyone that you actually can trust. Furthermore, if you’re that type of manager or leader, not only is the likelihood that you’ll be able to scale your organization quite low, but you have nobody but yourself to blame for the eventual failures you’re sure to encounter. Issues related to dynamic languages and static typing are the least of your worries. Rather than tying your developers’ hands, it’s far better to devote continual effort to instilling common values and culture across the organization so that your teams can work toward common goals without requiring constant centralized oversight. Read Peter Senge’s The Fifth Discipline for great insight into this area.

For me, dynamic languages mean increased productivity. It’s as simple as that. It’s because the programming languages I use actually can do this, and because succinctness is power. And if you’ve never actually tried developing real software in such languages, that’s too bad, because that power — that productivity — really is quite amazing.

Answers for Sergey

November 17th, 2007  |  Published in distributed systems, dynamic languages, REST, WS-*  |  Bookmark on Pinboard.in

Sergey Beryozkin, a former coworker at IONA, has posted some questions specifically for me. Questions are good; it’s almost like being interviewed, and it’s certainly better than being called sad and depressing! Let’s see if I can provide some answers.

But first, I want to address something I keep hearing when I post things like the answers below: “Steve, you’ve changed your whole story ever since you left IONA!” While the technical opinions I’ve been expressing in this new blog might seem shocking since they seem different from what I used to say, they’ve actually been under development for a long time. What actually happened is

  1. My technical opinions changed gradually over the course of 5 or 6 years while I was still at IONA.
  2. I finally chose to leave because my preferred technical direction had diverged significantly from where IONA was going.
  3. I left when I did because of a wonderful opportunity that came up at a new place where I could put all my latest ideas to work. So far, it’s all I hoped it would be, and more.
  4. I couldn’t publicly blog about my new opinions, write about them in my column, or present them at conferences until after I had changed jobs, for obvious reasons.

If you had enough time and patience to read through all my IC columns, you’d certainly find plenty of evidence that my thinking about all this stuff had already been changing for years prior to my departure from IONA. I hope this clears things up for those of you who mistakenly think I’ve just done an abrupt about-face.

Now, on to Sergey’s questions:

1. Do you think client code generation is evil ? If yes, do you expect people to do manual programming on a large scale ?

In days long gone by, code generation clearly helped us get a grip on certain types of distributed systems, and make advances as a result. But since then we’ve learned that you can’t pretend a distributed system is a local one, that RPC is less than desirable, and all kinds of other lessons.

All in all, I am now of the opinion that it’s generally best to avoid distributed system development based on language-first approaches (unless it’s a language like Erlang where distribution is effectively built in, but even then you still can’t ignore distribution issues). Code generation is based on the notion that I want to develop my distributed system using the idioms and practices of my programming language, which I now believe is almost always wrong. If you avoid specialized interfaces and use a uniform interface instead, it significantly reduces the need for code generation. On top of that, using standard MIME types for exchanged data rather than making up your own data types in WSDL or Java pretty much eliminates the need for code generation in many cases, IMO.

Now, I have to say that your question seems to imply that code generation is required for large-scale development. I don’t see why that would be the case. “Manual” programming isn’t much of a chore when you choose the right language.

People seem to get really upset when I say that the static typing benefits of popular imperative languages are greatly exaggerated, and when I say that developing real, working systems in dynamic languages is not only possible, it’s preferable. I usually find that, coincidentally, those are the same people who’ve never honestly tried the alternatives. Some who actually do try the alternatives do so by trying to use the new language exactly the same way they use their favorite language, and when they fail for what should be obvious reasons, they blame the new language.

2. If code generation is acceptable, would you welcome WADL? If yes, what to do with generated client types with respect to the change management ?

I’ve personally never encountered a need for WADL, but that’s just my opinion and experience. Marc Hadley and others obviously find it useful, and the RESTful Web Services book promotes it, and they’re all smart folks, so maybe there’s something to it.

Either way, no interface definition language is ever going to keep you or some other real live person from having to figure out what the service actually does and how to actually use it, and then coding your client accordingly. Normally you figure out that sort of thing by reading some sort of human-readable document, not just by looking at WSDL, WADL, or any other IDL. So if you have to read a document, and you’re avoiding code generation thanks to the uniform interface and the use of standard data formats, why bother with any IDL?

3. Do you think the idea of interfaces is broken ? Do you see any point in creating minimalistic yet not generic interfaces with encouraging users to focus on data ?

I believe that it’s important to avoid specialized interfaces whenever possible and prefer a uniform interface instead. Interface specialization, even of the minimal variety you mention, inhibits reuse. My Jan/Feb ’08 IC column, which is not yet published but is already written, covers this in detail.

4. Would you expect in the future even software modules interacting with each other through a common generic interfaces ?

I assume you’re referring to modules residing together within a single address space. To some extent that’s already been happening for years, thanks to frameworks, which of course are also based on interface uniformity. But will we ever get to the point in the foreseeable future where all entities residing within a single address all have the same generic interface? No.

Remember, REST is an example of applying well-chosen constraints to achieve desired architectural properties for a broad class of distributed systems, and so that’s what its constraints are all about. It might be an interesting brain game to consider what properties REST’s constraints could induce within a non-distributed system, but I’m not sure the exercise would be of any practical benefit.

5. “WS-* was simply not worth it to any customer or to me” – was it not ?

The customers that I saw benefit from WS-related technology gained those benefits only because of IONA-specific innovations that were not part of WS-*. In general, WS-* didn’t do anything for them that wasn’t already possible with prior technologies.

6. Do you think WS-Policy is a useless technology ?

I personally have no use for it.

7. Do you think AtomPub is the best way to do REST ? Is AtomPub better than SOAP ?

AtomPub fits a particular class of problems, but it targets only a subset of what REST can be applied to, so it doesn’t solve everything (and neither does REST, of course). I don’t believe AtomPub and SOAP are directly comparable, but I personally haven’t found a use for SOAP, other than when I’m forced to talk to systems that offer only SOAP-based interfaces.

In 1999-2000 I thought SOAP was finally going to help glue the CORBA and COM worlds together and make for a happy integrated place. But as I learned more and more about REST, starting at roughly the same time, I saw the light that SOAP was missing the boat, big time, by abusing HTTP.

8. What is a better way to protect investments made into WS-* ? Throw them away and start from scratch or start embracing the WEB while improving on what can be done with WS-* ?

I’m not sure there’s a general answer to this question, as it’s not really a technical question and it depends too much on particular business situations. Personally, if my current job involved WS-*-based systems that I had any say over, I’d throw them away, but I’m in a startup and we could easily do that. Thankfully, though, we have no such systems.

9. Do you think an “integration” problem IONA has been so good at is an “overblown” problem ?

I think that in the whole scheme of things the integration problems that IONA is good at solving are not very common. Nevertheless, those problems are very real; that’s IONA’s niche, and they’re great at solving them. The very bright developers, customer engineers, and sales engineers at IONA regularly come up with wonderful well-engineered and budget-pleasing solutions when nobody else in the industry can. But if you work in that environment day after day, it’s only natural that you might start to think that all integration problems look like those uncommonly difficult ones. In the big picture, that’s just not the case.

10. Can you please, if possible, describe a bit what kind of (software) clients will use your RESTful systems, (Web)UI tools or client software modules pushing the data up the response chain ?

In general, the company I work for is in stealth mode, so there’s virtually nothing I can tell you. But I will say that when you’re building RESTful resources, you tend not to think of the browser and other client software differently — they’re both just clients. If you’re primarily doing Web development and maybe sprinkling in some support for programmatic clients for good measure, that’s different. Either way, anti-REST folks commonly claim that REST’s success is due only to the fact that there’s a human-driven browser in the mix, but that’s one of the dumbest things I’ve ever heard.

11. What is the difference between service factories found in Corba and RESTful services creating new child resources as part of POST (as far as managing child resources is concerned) ?

As far as managing child resources is concerned, the difference is that CORBA has no uniform interfaces or data representations. The CORBA client therefore has to be specifically coded to be able to manage the newly-created resource.

12. Do you always prefer dealing with fine-grained resources ?


There’s No Hope For IT

October 29th, 2007  |  Published in dynamic languages, enterprise, REST, services  |  Bookmark on Pinboard.in

When you read stuff like this, you can’t help but feel that IT is, without a doubt, doomed.

The gist of the posting is

  • REST is too hard for the average developer
  • Dynamic languages are too hard for the average developer

Along these same lines, a couple of folks told me in person that my recent blog entries about REST, dynamic languages, and ESBs were misguided because today’s enterprises are interested only in approaches, frameworks and platforms that allow average developers to produce quality systems.

This all strikes me as nothing but wrong-headed thinking.

On the dynamic language front, the worst code I have seen in my career has always, always, always been in compiled imperative languages, most often Java and C++. I would much rather let an average developer loose with a dynamic language, because the surface area is smaller, there’s a lot less rope available for self-hanging, and if they’re going to fail, they’ll fail way faster and thus allow much more time for recovery. The fact that dynamic language programs are usually smaller than their compiled counterparts means that they’re easier to read and review, and statistically, they’re likely to have fewer bugs. Furthermore, counting on the static language compiler to save you is simply wishful thinking. To paraphrase Tim Ewald from a conversation he and I had during lunch a week or so ago, compilation really amounts to just another unit test.

On the REST front, if you’re claiming that it’s harder than the alternatives, to me that’s just a sign that you don’t understand it. Is REST simple? No, but neither is SOA. However, unlike SOA, which is fairly wishy-washy, noncommittal, and loose, REST’s constraints provide real, actual guidance for developers, and those same constraints also provide opportunities for significant flexibility, extensibility, performance, scalability, and serendipity. SOA’s contracts come with no rules or constraints, and thus can easily result in a system that’s extremely brittle, tightly-coupled, and virtually impossible to upgrade. SOA itself isn’t inherently bad, as it’s certainly a step above the “every application for itself” mode of development that’s so widely practiced. Unlike REST, though, SOA doesn’t go nearly far enough to provide real, useful guidance to the poor developer who has to actually write the stuff, make it work, and keep it running.

And finally, regarding the overall notion that enterprises cater only to average developers, I’m not sure I agree. In my former life I met countless enterprise developers who were extremely sharp. While I have no doubt that there are numerous bean-counting CIOs and middle IT managers out there who think they can build high-quality IT systems with low-quality developers, at the end of the day, businesses generally know better than to think they can get something for nothing. Or to put it another way, they know they get what they pay for, and if they pay only for average developers or worse, they’ll get only average software and average systems, or worse. That’s a no-brainer.

If you’re in a position of technical leadership or project management and you’re asked to come in ahead of schedule and under budget, my advice is that you’re generally more likely to succeed with REST and dynamic languages than with the alternatives because their inherent constraints allow for better focus. Also, if you find yourself in such a position, you owe it to yourself and your team to continually lobby your superiors to help them understand the very real costs of their budgetary stinginess.