Archive for the ‘ksplice’ tag

Two celebrations, two observations

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It’s late and I’m going to bed, so this will be short.

This weekend was packed for me with fantastic, joyous events that don’t happen every year. An old friend got married, and the Harvard Glee Club and its two sister choruses held a huge reunion to mark the retirement of their longtime conductor. (The latter was joyous in reunion and in remembrance of his career—not in the fact that he’s leaving!) At each event I caught up with a number of people I hadn’t seen in several years, and at the wedding celebrations I also met a large number of young mathematicians, colleagues of the bride and groom.

Two observations. First, at the Glee Club reunion I saw a cross-section of Harvard graduates between one and five years out, and heard what they’re all up to. One thing I heard from very few of them was that they have today a job directly on the career path they want to follow for life. Maybe half are in graduate school of one sort or another, some after working a job, some not. Many of the rest talk about entering a program next fall, or applying next year. One guy quit his job last week, another is going to quit next month—either to write plays, or work in politics, he’s not yet sure which—and another has realized he hates his job and the whole career path it lies in and is trying to figure out his next move so he can quit too. While in school, particularly senior year, it often seemed like everyone had their whole future paths exactly figured out. It’s comforting in a way to know that so many of them were wrong.

Second, everybody still loves Ksplice. I must have told at least thirty people, either that I’d just met or just caught up with after years, that we make those ‘reboot’ popups obsolete. Most everyone was suitably glad to learn of the idea; one reached out and shook my hand a second time. And then I think I broke new ground for Ksplice when one of them was so happy for the death of reboots that he gave me a hug.

Written by Greg Price

May 3rd, 2010 at 2:45 am

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Ksplice and the intern army meet the Internet

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This week I wrote a post on the Ksplice blog, our first substantive post, following an intro post by Waseem. As I mentioned last month, we swelled from 8 to 20 people this January with interns, and were triumphant in making the whole scheme work productively. If you want to know how we did it, read the post. In fact, just go read it. I’ll wait.

The crackerjack Ksplice PR team (*) got my post to show prominently all day Wednesday on Reddit and Hacker News, and then it went up on Slashdot all Wednesday evening and Thursday during the day. Traffic numbers were much, much more than anything else I’ve ever written, except YouTomb.

Naturally, we learned some things about interacting with your average comment-leaving reader on the Internet. The first wave of comments, a few both on link aggregators and on the post itself, were vicious denunciations of us for the (apparently) illegal practice of employing unpaid interns to do real work. These commenters were of course wrong—you can’t get any intern in software for free, let alone the kind of people we wanted, and we paid as much or more than they could make with their skills in research jobs on campus. I clarified that, I and others replied, and the comments shifted to mostly positive. Then when we landed on Slashdot, the text was a classic opposite-of-the-article Slashdot item: we had claimed to “bust” Fred Brooks’ pioneering observations on software project management. Dozens of commenters poured in to grouch that we hadn’t disproved his law, only sidestepped it—which was of course our point.

Fortunately, not all commenters are just being wrong. We had several good comments, but this afternoon came one last comment from a source far beyond any response I imagined. I feel a twinge of regret now for comparing the OS/360 project to Windows Vista, apt though it was. Prof. Brooks, of couse, did far better than the Vista managers in the end, in that he learned lessons from the experience and put them in a book that the whole profession learned from.

How we’re going to top that comment in our next post, I don’t know—it might be tough, for example, to get a comment from a man who hasn’t used email since before blogging was invented.

(*) Namely, us and our friends on zephyr/twitter lending a few upvotes to our posts. Several others at Ksplice made substantial comments and edits before the post was published, too, which greatly improved it.

[Update, 2010-03-18: there is now a straight-up newspaper-style article about... the comment threads on my post. The Internet never ceases to amaze me.]

Written by Greg Price

March 15th, 2010 at 3:23 am

Web design goes global


Last month, we decided at Ksplice that it was time to redesign our website. We had a very clean website that we had developed in-house, but we’re finally selling our Linux security product directly on the Web, we’re beginning to seek greater publicity, and it was time to make a website focused completely on selling Ksplice-Uptrack-the-product rather than explaining Ksplice-the-company and Ksplice-the-technology. This time, we also wanted to get the design from a professional web designer, to see what they do differently.

In the olden days, I gather the way a company might have done this is to find a web design firm in SoHo (or maybe Beacon Hill or Brookline for us) and pay them $20K to make an array of gorgeous mockups on their 30″ Apple Cinema Displays in their loft offices, display them in a presentation for our admiration and our selection, and then turn out perfect XHTML.

I’m not sure it ever worked quite like that in the real world. But in any case it turns out that’s not the world we live in anymore—a good thing, too, because as a bootstrapped startup it’d be hard for us to justify spending $20K on a website at this stage. Instead of a firm, we hired a freelancer. Instead of SoHo, he lives in Sri Lanka. Instead of $20K, we paid on the order of $1K all told—and it would have been under $1K if we had started with a clear sense of how much things should cost in this market. And instead of a theatrically delivered client presentation in our office, the mockups were delivered in a string of emails as I communicated with our designer—let’s call him “Sajith”—over Google Talk to iterate through designs while North America was deep in the night. It’s not hard to see the logic that drives this new way of doing things: $1K is six months’ worth of per capita income in Sri Lanka. Sajith is making a nice living for himself on fees that even a cash-conserving startup like us can easily pay.

Here’s how it works:

  1. Post a project on a freelance job board—I used
  2. Wait for bids. We were running on our characteristic tight schedule, so I set a 24-hour deadline, and in that interval 26 people and firms offered to do the project.
  3. Pick someone. Most of the bidders’ portfolios were terrible, some qualified as mediocre. I went for the only one whose portfolio looked good.
  4. Get mockups and iterate. This was the next-to-longest stage of the process. I spent many late hours with Sajith as he presented a mockup image of the page, I made comments, he went off for a few minutes to implement them and I half-worked on something else until he came back, etc. One of the pitfalls: English language skills may not be what you hope for. I learned to give instructions in short sentences, and gave up on trying to get text right in favor of us correcting it later.
  5. Slice. This is apparently the word for taking a mockup and producing an HTML document, CSS, etc, that implements it. More on this step below.
  6. Integrate and polish. Our sites comprised a Django application with a handful of distinct pages, and our mostly-static main website with a large number of pages, of which we were only redesigning/adding a few of the most critical for selling our product. Taking Sajith’s static HTML and turning it into Django templates that behave in all the right ways, getting all the right text in place, and dealing with final improvements to the HTML and the CSS to the point where we were happy, consumed about three person-weeks of engineering time on our end. I knew there would be work to do here, but we were completely unprepared for how much work it was.

I’ll close with the episode in this process that really made me feel I was living inside a Tom Friedman book. We were humming along on our aggressive schedule, and one day Sajith failed to deliver on a deadline: he was to get a page of sliced HTML to me that morning, his evening. I pressed him as the hours passed—OK, I understand some details aren’t finished, can you get me what you have? We want to start on integrating it. Eventually he confessed that he wasn’t doing this work himself; rather, he had himself gone out and found a subcontractor, somewhere else in the world, who had promised to do the slicing, and the subcontractor had failed to come through. (Apparently he had done the job and then accidentally deleted it—someone needs to learn about source control.) After another failed subcontract attempt the next day, Sajith gave up and did the slicing himself. Maybe the outcome of Sajith’s experiment suggests we don’t live in Friedman-flattopia just yet.

Written by Greg Price

February 8th, 2010 at 5:46 am

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A simple code review script for Git


This January, Ksplice swelled from 8 people to 20 people. You can imagine what that did to the office—it’s a good thing that Tim and Jeff have been practicing the art of rearranging a space to fit more people than ever thought possible since their days in the SIPB office. Fortunately, because we have at our disposal a computer-systems training and recruitment machine of awesome effectiveness, our interns defied Fred Brooks and produced a great deal of useful code.

The problem: how to keep track of all that new code and get it all reviewed smoothly? Our ad hoc practices relying on one-on-one exchanges clearly were not going to scale. The solution: on the first day the new interns showed up, I took a couple of hours and threw together a script to request code reviews. The key design considerations were

  • Public visibility. The script sends mail, and CCs a list going to the whole team.
  • Non-diffusion of responsibility. The user must identify someone to be the reviewer, and the request is addressed to them.
  • Git friendliness. Being a kernel shop, we use Git for everything, so the script assumes a basic Git workflow: you make some commits, and then you request a whole series of commits to be reviewed at once.

We looked at some existing code review tools like Gerrit and Rietveld, but we weren’t happy with any of them because the ones we found don’t work on branches—they work on individual commits—and we have drunk too deeply of Git to be satisfied working that way.

On the other hand, being the product of a few hours’ work, there’s several things that could be made better. The interaction with the user could be better to prevent mis-sends. The script could do better at detecting what the repository in question is called, it could take advantage of commit messages for better subject lines, and it could try to give the reviewer a command line that will show the commits in question. (Until then: it’s usually git log -p --reverse origin/master..origin/branchname.) Someday we may also want a system that tracks what commits have been reviewed by whom and blocks commits from going in without review; that will be a bigger project.

Apparently we did something right with this script, because I heard a couple of people say they’d like to use it outside of Ksplice. So the other day we decided we were happy to release it as free software. As of last night you can get it from Github—enjoy.

Let me know if you use it, and patches welcome, of course.

Written by Greg Price

February 1st, 2010 at 3:56 am

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Read-Write Software

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My favorite moments with free software are when I get annoyed with some manual task that a tool leaves me to do for myself, and then invent a feature that the tool should have to handle the task for me.

With any software free or proprietary, if I’m lucky the tool might have a configuration system powerful enough to let me effectively add the feature from the outside. But with free software, I don’t need the authors to have anticipated my needs—I can reach into the guts of the software itself and change it to work the way I want. If it’s a friendly codebase or if I’ve hacked on it before, I may be able to add my change in a few minutes. And hey presto: software that does exactly what I wanted. It’s a lot more fun than praying to the vendor and waiting a few years, and it’s faster and more reliable too.

So it went with Git one night last October. I was repeatedly revising a branch with git rebase -i. A couple of points along the branch were marked as branches of their own, so every time I changed something I would have to either

  • rebase the full branch, then do a dance with checkout and reset to update the sub-branches, carefully typing the correct new commit IDs;
  • rebase the full branch, then muck with update-ref with the same care about getting commit IDs right; or
  • rebase the first sub-branch, then use rebase --onto to move the next sub-branch on top of it, then rebase --onto again for the main branch

What I really wanted to do was just

  • rebase the full branch, and tell the sub-branches to come along for
    the ride.

Fortunately I’d worked on the code for Git’s interactive rebase before—at Ksplice we push Git to its limits in six different directions, and rebase -i we push beyond the limits of stock Git—so I knew where to find the moving parts that could do what I needed. Four minutes after having the idea, I was happily using the new feature.

If you want the feature too, it’s up on my Git git repo. Or you can wait until I get it upstream. Why haven’t I done that already? That’s another old story about software. My 4-minute, 4-line patch turned into 29 lines with documentation and with proper error handling, then 147 lines to make the feature easy to invoke, and then 231 lines with test cases. So I just finished all that work today. Maybe you’ll see the feature in Git 1.7.1 this spring.

Written by Greg Price

January 25th, 2010 at 2:30 am

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The Soul of a New Machine

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At Ksplice, we put a lot of effort and discussion into how we manage projects, in part because we know we aren’t as good at it yet as we’d like to be. Books by managers and books for managers lie scattered around the office and employees’ rooms. So imagine my surprise and delight the day after Christmas when I opened The Soul of a New Machine, Tracy Kidder’s 1981 classic about the machines that made the computer age and the geeks who built them, and discovered it was about project management.

Keith sometimes remarks that Ksplice needs a documentarian. The Soul of a New Machine is the result of a project that had a documentarian, one who produced prose. The Eagle project at Data General set out to build a new computer, a 32-bit version of the existing 16-bit Eclipse line, just as DEC raced into the lead in the minicomputer market with the 32-bit VAX. Tracy Kidder, a writer for The Atlantic looking to write a story about technology, connected with his editor’s old college roommate, the leader of the Eagle project, Tom West.

The story that Kidder tells is full of implicit lessons that look as current today as they were in the computing projects of thirty years ago.

Schedules. Everyone knows that computing projects run slow. When the Eagle project started in July of 1978, it set an insanely fast timeline to have the whole computer architected, designed, built, and debugged by April 1979. They didn’t make it, of course, and many team members expected that from the start. But at every stage West, the engineer in charge, insisted on treating the schedule seriously—”come on, this schedule’s real”—setting intermediate deadlines as if the April date would be met. And though April slipped, the project was done in October, just fifteen months after it started and still a rapid turnaround by anyone’s count.

Delegation. On a big project, the person in charge can’t do everything themselves, or even keep a close eye on all of the work. They have to rely on others to do it right. Good managers know this, but it’s nerve-wracking to actually put it into practice. West itched to get into the lab and start debugging the prototype himself, telling Kidder, “Rocking back here in my chair and talking about doing it is one thing, but it makes me worry. It gives me a nauseous feeling, because I’m not doing it.” Eventually, as one lieutenant puts it, he “gripped the arms of his chair and decided to trust” the engineer leading the hardware team.

Perfect vs. done. Before Eagle, some of the same engineers had worked on projects to build a 32-bit machine from scratch. None of these projects were completed. Eagle would be tied by backward compatibility to the 16-bit Eclipse, and at the outset some engineers saw the idea as “a kludge on a kludge on a kludge”, or “a paper bag on the side of the Eclipse”, and wanted nothing to do with it. Yet West convinced them all to sign on to the project anyway, and in the end it was the compatible computer that was completed, sold well, and rescued Data General.

It’s not only the lessons that seem not to have changed. Some of the engineers on the Eagle project recall how as undergraduates they would “stay up all night and experience … the game of programming”, and we can all think of people thirty years later who, like a few of them, “started sleeping days and missed all their classes, thereby ruining their grades.” One comforting thought: Carl Alsing, the engineer in charge of the microcode team, was one of those who actually flunked out of school.

Finally, a word about the writing. The technical exposition is incredible. On the one hand, the reviewer for the New York Times heaped praise on the prose that enabled him to “follow every step” despite knowing nothing about computers (and a reviewer writing in 1981 could mean that in a much stronger sense than any reviewer typing into their laptop today.). From my very different perspective, I was fascinated to learn details about the faraway architectures and design constraints of a different era. And in 291 pages delving frequently into technical aspects of computer architecture, digital logic, and software, I never felt condescended to and I found not one mistake.

Maybe Ksplice should get a documentarian after all.

Written by Greg Price

January 11th, 2010 at 1:27 am

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