Older blog entries for logic (starting at number 166)

Systems Administrators != Programmers

I had a good reminder today of what Erik Naggum was talking about when speaking with a co-worker. He was trying to come up with a "good" solution to a Perl problem, so I had him describe it to me. It turns out that he has an object, which may or may not contain the attribute he's looking for. If it doesn't have it, the object has an attribute referring to another object. This other object, in turn, may or may not have the attribute he's looking for, and also has a reference to another object; this repeats until the "next object" is null.

Astute readers will have recognized this as a basic linked list.

I figure, okay, he hasn't been programming in a long time, so we'll mentally walk him through it. First, a quick nudge to see if he can remember his basic CS from a long time ago: "Why don't you write something that will just recurse through that list?" He nods, but the eyes, they don't have it. He goes away to think about it for a while, and then we wind up on a conference call in a meeting room. While the person we're calling is talking, he's quickly jotting down on the board:

  O -> O -> O -> ...

I think, okay, he has the mental idea now, because he's diagramming it correctly. We talk a bit more, and he's obviously trying to come up with a way to iterate over the list. Once again, I suggest a simple recursive function (because that's natural to me, goddamnit, I don't care what you iterative programmers say), and quickly psuedocode something up for him:

  function blah(o)
    if !o:
      return null
    if o->whatImLookingFor:
      return o->whatImLookingFor
    return blah(o->nextObject)

  found = blah(myList)

He looks at it, and appears puzzled. This appears to be a new construct to him, and he asks a few questions that confirm this. "But it'll just keep calling itself and looking at the same object all the time, won't it?" My first psuedocode example unfortunately used similar variable names in both the "mainline" and the function itself, but after renaming things, he still didn't seem to understand. Ah! Local vs. global scoping rules, maybe? So I suggest that, in Perl, you'd have something like my ($o) = @_; as the first line of that function. He still doesn't get it, and grunts something about just dumping the objects and grepping for what he's looking for. He just couldn't make himself look at the "CS" solution, because it didn't fit what he was expecting from Perl: a quick hack that did what he wanted without having to think too hard about it.

Systems administrators who spend to much time with "qwiky" languages like Perl are doomed to forget everything they ever knew about Computer Science. I'm convinced of this now. You might think I had this conversation with a newbie programmer or someone who whipped up scripts now and then, but you'd be wrong; this is a fellow who did software development professionally, and moved into systems administration later in his career. He's no idiot.

(I liken the problem to "l337 sp33k". I've known colleagues who could carry on a perfectly professional conversation face-to-face, but the moment they sit down at a keyboard, they immediately regress to "OMG r u 4 r34l?!" and, setting aside perceptions, they actually behave dumber while doing this. Perl has a similar effect on programmers; in the end, you end up with something that's a tangled web of spaghetti code and system() calls, getting the job done but disgusting anyone who has to look at it. Sort of like reading, "omg u pwn3d that bug, yo!". I wonder when someone will spec a programming language called "l337"...nevermind, Google to the rescue. Ye ghods.)

Postscript: yeah, I probably should have given him an iterative version of the pseudocode. Something like this:

  function blah(o):
    while o:
      if o->whatImLookingFor:
        return o->whatImLookingFor
      o = o->nextObject
    return null

Just as simple, conceptually. Maybe some people have trouble wrapping their heads around recursion, but it's always seemed like a very straightforward idea to me.

Syndicated 2006-04-29 02:46:00 from esm


Go away. :-) The funny thing? I'd use IMolatr.

Syndicated 2006-04-28 23:49:00 from esm

Code Monkey

Code Monkey think maybe manager want to write goddamn login page himself.

Pure geeky comic gold from Jonathan Coulton's "thing-a-week". :-)

Syndicated 2006-04-24 15:22:00 from esm


If you can read this (and in some parts of the 'net, you probably can't), then you're reading it through our new network connection via Comcast. After a pretty nasty false start over the weekend, and the cutoff date for Dataflo coming up this weekend, I bit the bullet and cut things over this morning. DNS was set up such that NS records were available for both address assignments for a while now, as well as MX records pointing at both address pools, so the only thing that's really off the air right now in some places is the webserver, and that'll just have to wait. I also managed to break my backup MX along the way, so I'll need to poke at that a bit more and see what I fat-fingered.

Bah. I like renumbering about as much as I like moving.

So, some initial observations: latency is a touch higher than it was with Dataflo, surprisingly enough. First hop averages went from 2-3 ms on the old wireless link to 8-10 ms (with occasional spikes) on Comcast. On the other hand, I'm now seeing download rates around 6Mbps (vs. 1.5Mbps), which is a nice change of pace. :-) Downstream speed is 768kbps now (vs. 1.5Mbps through Dataflo), which may prove to be a problem, but we'll see how it goes for now.

The biggest negative observation I've made so far is Comcast's complete lack of business-oriented customer service; they're obviously incredibly used to dealing with residential customers, and they've used that same contracted-out infrastructure to deal with their commercial customers as well. Phone support is excellent (when you finally get to them; getting a rep on the phone requires navigating about 10 levels of phone menus), but getting physical on-site service is a multi-day waiting game, with the typical "we'll be there sometime between 8:00 AM and 8:00 PM" kind of scheduling that you've come to expect from their residential service. There is no email interface to the helpdesk whatsoever; any kind of technical support inquiry MUST be made by phone, which is incredibly annoying when wanting to do something complicated with DNS. So far, I'm not impressed, but if I never have to deal with their customer service (much like when I was with Speakeasy, who rarely saw an unannounced service outage), then it won't matter to me. We'll see.

Syndicated 2006-04-18 09:53:00 from esm

Dataflo or Datanoflo?

So, the day after I post a blog entry about being forced to switch to Comcast because of the lackluster service I've received with Dataflo, I have another rather significant service outage. There appeared to be problems last night, although I was having a hard time pinning the issue on Dataflo then. However, they definitely made a mid-day routing change today; at 12:34, all of a sudden, my backup MX starts receiving email for everything (the backup MX, in this case, is my router, which usually sees nothing but spam all day), and traceroutes to the static IP block they've assigned me are dropped on the floor the moment Cogent hands off to Dataflo.


It's not like I'm asking for a lot here. I need a service that stays up, and I'm paying a premium for that. That premium ought to include at least a bit of special attention to making sure the services provided to me are working when a major change is made, and perhaps major changes shouldn't be done in the middle of the workday, in the middle of the week, without any prior notification to the customer base of a potential outage. Screw the SLA; I shouldn't need an SLA to hold over their heads. What I really need is a service that stays up, with planned maintenance windows and some degree of customer notification.

I have no idea why I think Comcast will be any better, but at least they're half the price (actually, a third of the price, if you consider what my renewal contract pricing stated). In the event I get lousy service, at least I won't be crying about the money I'm wasting.

Syndicated 2006-04-04 14:52:00 from esm

I'm Comcastic!

Ugh. I finally bit the bullet, and had Comcast "Workplace" service installed to replace the flakey fixed-point wireless service I've been fighting with for the past two years. To be fair, I should qualify that: my "last mile" link (between my rooftop transmitter and the tower) has been rock solid. The problem has always been mid-day routing and configuration changes on the part of the provider, which have knocked me offline anywhere from a few minutes now and then, to one incident that had me offline for the better part of a day. At this price and service level, that's completely unacceptable. So, since I can't get service from my preferred vendor here due to a complete lack of DSL availability in my area, I'm stuck with the local cable company: Comcast.

So, first impressions (note that I haven't moved ANY services to this yet, until I get a feel for how this will work): 6Mbps download speeds are unbelievably fun. :-) The 768kbps upload speed may end up being a bit of a hindrance; most of my traffic is SMTP, but I do receive a fair bit of HTTP traffic too, and that's where that upload bottleneck is going to suck (specifically, both I and Erica maintain pretty large photo galleries that seem to get a bit of traffic, and I'll often host larger items for people for limited times). But, we'll have no idea how that'll go until I bite the bullet and cut stuff over; I'm hoping I can run fairly well off of both links for a while, with plenty of time for DNS updates to propagate.

Ugh. I remember how much I hate renumbering now.

Syndicated 2006-04-03 11:29:00 from esm

Fedora Core 5

My initial impressions: more solid than I thought this release was going to be, given how much has changed. My biggest complaint so far: they upgraded OpenSSL to a new major version without providing a compat release for those of us upgrading. All we needed was an equivilent to the already-existing openssl097a package, which does nothing but package up libssl.so.5 and libcrypto.so.5, and upgrading would have been smooth as silk for me on one machine. Instead, I'm stuck rebuilding packages that I should have been able to leave alone until later. Bah.

More later when I've had a little more time to play with it. Playing with it on a desktop machine is proving difficult, as the only "play" machine I have right now running Fedora Core hangs the console whenever I fire up X. (Not too surprising, that machine is a bit of a hodgepodge of hardware.)

Syndicated 2006-03-30 20:50:00 from esm

Treo 650

The action with the WRX was captured beautifully with my new toy: a Treo 650. It's a combination PDA and cellular phone that runs PalmOS, and with the data service I picked up with the package, the built-in web browser and email client are actually proving to be fairly handy. Definitely a big step up from the BlackBerry I had while I was at my previous job; the screen and form factor are a huge leap forward, and having a camera built-in (albeit pretty crappy) is a cute gimmicky toy. Battery life is at least as good too (actually, it looks like it's going to be quite a bit better; I should get two or three days out of a charge with my normal usage, which is pretty excessive compared to an average user). Phone and data service coverage with Sprint seems to be pretty good so far, and the data service is a LOT faster than the Nextel service I had the BlackBerry connected to. The SD media slot means this thing can also serve as a portable MP3/OGG/media player too; 2G of audio storage ain't bad. I can bolt the thing up to my desktop via bluetooth and infrared as well, which means one less cable to muck with. I'm pretty happy with it so far. :-)

Syndicated 2006-01-01 02:27:00 from esm


So, in my new role, I'll be responsible for the shared administration of a rather large Gentoo deployment. So, in the spirit of eating your own dogfood, I'm loading my new company-issued laptop with Gentoo Linux.

First impression: I feel like I'm back in 1994. Really. Oh, the package management is generally pretty cooked; in fact, I'm really quite impressed with how they're handling a generally nebulous thing (from-source package generation) in a pretty consistant manner. I'm trying to imagine building Fedora from source RPMs, and the idea gives me the willies; they have the build dependancies handled pretty well. No, my problem is the same problem I have with Debian: choice is good, but too much choice is a PITA. You can infer from this that I disagree with the Perl axiom of "more than one way to do it"; all that means is that the language (or in this case, distribution) maintainer didn't have the intestinal fortitude to make a decision, and left the problem of bikeshed arguments to the users. It's actually worse than that: on their own, a lot of the little variances don't matter, but get enough of them together, and you have a maintenance nightmare.

This problem is compounded by the community belief that customization at all levels (specifically at the buildchain level) is a good thing. At the end of the day, you have a distribution where you are truly on your own from a support perspective in many cases. Not a big deal for an operating system targetting hackers and tweakers (in fact, I'll probably have a ball with it on my laptop), but when I put my management hat on, the idea of using this in production frightens me; you're essentially locking yourself into using senior-level talent to manage your infrastructure, and hiring junior talent that can grow into the position starts becoming less and less attractive. Not bad for me, but bad for the bottom line.

I expect I'm expounding on arguments that have been had over and over in the Gentoo community over the years, so this is more of a first-impression kind of vent. I'll skip on discussing the apparent lack of development and "stable" tracks for general deployment, and a few other similar things I've noticed missing from the "process" around the distribution, because they're all fundamentally part of the same issue: the Gentoo community appears to strongly appeal to the hacker/tweaker, which defines the community's behavior from a packaging and ongoing maintenance perspective.

So, Slackware for smarter people. :-)

Syndicated 2005-12-15 10:11:00 from esm


After being so happy about getting the framerate up a bit last night, I decided to finally get around to updating the BIOS to the last version issued by ECS (it's a K7VZA v1.0 motherboard, if anyone's curious). Seeing as it's been out since 2000, I figured, "What could possibly go wrong?"

I ended up with a brick.

Enter the Willem EPROM burner I bought a few months back for flashing ECU chips for Erica's Laser. I finally set up a machine for doing nothing but burner duty, and pulled the image off the chip. As suspected, it was corrupt, so I tried writing the image out again with the burner...no dice, it would fail after a random number of sectors. After a LOT of searching, I turned up a bit of information: first, BIOS chips (in this case, an ASD AE29F2008) seem to have a defence mechanism against just blatting a new image onto them, and you need to disable this before you can write your image (which is the real "magic" of the flash update software that motherboard manufacturers issue you). Second, version 0.97ja of the Willem software (the most recent version available) can't actually disable it; you have to backdate your version to 0.97g. Tried out the older version, clicked the button that magically appeared to disable software protection, and viola: the image burned perfectly.

Shouting triumphantly (and waking Erica up, doh!), I rushed downstairs with my freshly flashed BIOS, plugged it in, powered the machine back up, and...BEEEEEEEEEEEP*crackle*. Same thing, just powered down. Dammit. Okay, back upstairs, downloaded and burned the older version that we were running before, ran back down, plugged it in, powered it up, and all was well again. I have no idea why the new image isn't working, but I'm perfectly happy with the BIOS revision I have now, thankyouverymuch. :-)

I also took a second to slap another 30GB drive I had lying around into it for my ogg collection and various other multimedia goodies for sharing with the rest of the machines here. A quick fdisk and pvcreate /dev/hdd1 (etc), and I think I'm about ready to call it a night.

So, on the upside, I now have a decent station to burn chips at; this eliminates the last of my reasons for waffling on getting a new chip made for the Laser, so I'll probably play with that next.

Syndicated 2005-12-06 22:51:00 from esm

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