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Software Engineering at Microsoft
an_mo writes "A link to a google cached document is floating around some mailing lists containing some info about microsoft software engineering. In particular the document contains juicy bits about the development of a large project like NT/2K. Some examples: Team size went from 200 (NT3.1) to 1400 (Win2k). Complete build of win2k time is 8hrs on 4way PIII and requires 50GB of hard drive space. Written/email permission required for checkins by the build team." The HTML version on Usenix's site is much nicer than Google's auto-translated version.
It's long-ish, but not overly long. For a comparison that you may be more familiar with, consider the time it takes to compile the Linux kernel, your chosen libc, other libs you'll eventually need (say, gtk and/or qt, etc), X, GNOME or KDE, some apps (xmms, xine, a couple editors, etc), and probably 8 or 9 other things I'm forgetting right now. You'll probably come up with a similar number (probably smaller, but there's also probably less code in all the above tools).
That's not to say it can't be made faster. I don't know whether that time was on a multi-threaded compile or not, but I'd sure hope so given that their build machines were 4-way machines. Also, note that they didn't say what speed the P3s were. 4 P3-500s will surely compile slower than 2 p3-1.2GHzs. Nor did they say if those were Xeons or not (larger cache is better for compiling). The obvious solution is to throw hardware at the issue, but there are other things that can be done like incremental building, better sync/drains for multi-threaded compiles, more efficient compilers and build scripts, etc.
Only the NT build lab needs to rebuild everything. Individual developers only need to built their feature's DLL and EXE files.
cpeterso
I venture to guess, however, that your company is somewhat smaller than Microsoft, is held together by shared enthusiasm and the exilaration of short term releases, and that you don't face many of the problems that any large company, not just the Borg, does. I would never defend the quality of MS products but anyone who has worked on large products with many existing custoemrs in a large software company like an Oracle, Microsoft or IBM will understand that it is simply impossible to only hire expert programmers whose work never needs to be checked by anyone else and who don't need any supervision.
Some of your other statements are rather sweeping. Some parts of UML - such as object modelling - are very useful indeed and can act as highly rigorous sources for a lot of code and database generation or automated access. Others (like Use cases IMHO) suck and are of little use to programmers, though more in communication with PHBs and business types.
A lot of what you say is very true for small focused teams working in their bedrooms/garages/garretts but much less so for any large software developer who sells software for money. Your "expert-driven" approach would never work at a Microsoft.
Your last point, that OSS produces better results, is probably true. Certainly its more cost-efficient. But does it produce profitable companies that make heaps of money ? Maybe you don't like the idea of that. But most of the rest of the world, including your gray-haired neighbour who plans to retire on the proceeds of his portfolio, does.
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UML and other modelling fads. My former employer required the use of 65-page UML diagrams for the simplest command-line utilities. Why? Because it was popular, and the investors liked to make sure we were buzzword-compliant. UML is designed for non-technical audiences, and as such it flies in the face of the engineering goals it is designed to solve.
I've found UML, or at least quasi-UML, useful; any time I design a system I draw a quick UML sketch just to help me think about what's invovled. Unless, that is, it's something really dead simple .. something equivalent to a homework assignment. Sometimes most of the really hard work goes into a good UML diagram, and the rest becomes easy.
But despite this, I can't help but reflect on your statement in utter horror. What the hell kind of UML diagram does one put together for, say, ls? Or cd? Or a numerical calculation?
Code review. Code review is a power trip and best, and a drain on morale at worst. If a programmer cannot be trusted to develop excellent code, he should be replaced with somebody who can. It's a tight labor market on the developers' side, so incompetent programmers should be spending their time reading O'Reilley books instead of playing games and looking at porn in their parents' basement.
I disagree with you on two fronts. One, I've always found code review beneficial for a project. Weaker coders learn good habits; stonger coders teach good habits; bugs not visible to some become visible to others; the general quality of code improves. People who can't deal with constructive criticism of their code make for bad team-mates.
Secondly, I've never met anyone who became a good programmer by reading books, even books as high quality as O'Reilly's. I learned to code by writing code and reading others' code. The books make handy references, but sticking to books is akin to trying to learn to write well by reading the dictionary.
Large, geographically concentrated development teams. The best work is emphatically not done by 1400 people in the Redmond campus. The best work is done by culling experts of individual niche areas from around the globe. Not surprisingly, this is the model that Linux and most Open Source software uses, and that is why OSS is phenominally successful compared with any of its proprietary competition.
Most of Microsoft's problems can probably be directly attributed to the size of its development team. MS project designers might do well to re-read The Mythical Man-Month (if they never read it, they have no business being project designers, IMO).
Finding God in a Dog
Good engineering (of any kind) starts with design... a plan. I'm glad you don't build skyscrapers or airplanes. Oh boy. So you basically are thinking... what... that code should be reviewed after it has already hit QA or something? Or perhaps we shouldn't review code at all?
Here's a clue. If a developer is costing 20-40 per hour writing CRAPPY code... THAT is a far worse waste of time than taking a little time... reviewing the code... and correcting it if necessary.
Development isn't just writing code any way you want. You want things to be very solid, standardized, and consistent before it gets into beta. Using your way... you'd never know if the code was good or not. Apparently... to you... if it works... ship it! What? How do we know if the code is bad? We have to REVIEW it? What if the developer doesn't understand a certain design pattern and implemented it incorrectly? Hell... what if a bug or flaw is discovered during the review process?
These are all common issues in everyday development. It doesn't necessarily mean the developer is BAD. Rather... the developer is HUMAN.
Although... with your lack of a code review process, lack of system design process, and lack of formal check-in process... I am surprised that any decent code gets written at all. You're comparing apples and tractors. Financial gain or customer/user base size are NOT measures of good code, excellent development standards, or strong design processes. Although, I'm not certain you will understand what I'm saying here.
There is some excellent open-source software out there. Likewise, there is some excellent proprietary software out there.
And there is crappy software out there, too... for both worlds. Whether or not something is open source or proprietary says nothing about how it is written or how well it is designed.
This obviously is a huge troll that I'm feeding here.
# Code review. Code review is a power trip and best, and a drain on morale at worst. If a programmer cannot be trusted to develop excellent code, he should be replaced with somebody who can. It's a tight labor market on the developers' side, so incompetent programmers should be spending their time reading O'Reilley books instead of playing games and looking at porn in their parents' basement.
No, no, no. Code-review is VERY USEFUL. No, it won't catch architecture mistakes (necessarily). No, it won't catch design mistakes. Hopefully you already know how to design before you get your first software job.
What code-review catches is the annoying things that the best developers tend to think don't matter so much. Style-differences from company practices. Naming conventions not being followed. Poorly chosen variable-names. Lack of documentation.
In short, code-review makes your code more maintainable. Your company may not use it, but that doesn't make it useless.
Microsoft claims IE can't be separated from the OS. Yet, the presentation points out the code is broken into 16 sub-projects, largely isolated from each other, and separately buildable.
Two of those projects were "INetCore" and "INetServices".
So why can't you just build 2K without those 2 subprojects, or just stubs inserted for the functions declaired in those projects?
UNIX and Linux are different. UNIX (at least Research UNIX) was constrained by its paradigms: it was vigorously policed by its developers. For Linux, something doesn't make it into the kernel unless it really scratches an itch that a lot of people have--the feedback is immediate and direct: no interest, no developers.
Microsoft software development doesn't operate in a competitive market of ideas (let alone a competitive market), it doesn't have a paradigm to focus it, and it doesn't even have resource constraints to focus it. It's nice that they make the software engineering work out, but the end result still is mediocre at best.
Given the tone of most of the comments here, one might think that the slides merely reveal Microsoft's errors. In fact, they indicate what problems the company faced scaling their NT development team from 200 to 1400 programmers and their solutions. The conclusion is, "With the new environment in place, the team is working a lot like they did in the NT 3.1 days with a small, fast moving, development team."
As Linux grows, it is headed for the same sorts of problems. The open source movement can learn a lot from Microsoft's struggles. The fact that Linus opted to use a new source control system -- just as Microsoft realized that their in-house system was not up to the task and so switched -- gives me hope.
P.S. May we please have better summaries for the articles on the front page?
Can you see the spelling error you made in this sentence? Did you mean to make that error?
If you can't even type error-free prose, how could you be expected to create error-free code?
People make errors. Code review helps reduce the effect of those errors.
"You can justify anything by putting it in quotes, adding a famous name and making it a sig" - Albert Einstein