Jump to content

  • Log In with Google      Sign In   
  • Create Account

etodd makes games

Anecdotes ahoy

Posted by , 24 March 2013 - - - - - - · 1,053 views

A smorgasbord of anecdotes carefully compiled just for you, dear reader. This is #2 in a series of three posts which were originally one, before I decided I just had too dang much to say.


I spent a few weeks at work building a fully operational death star OpenStack cluster. What does that mean? Basically, we have our own little private version of Amazon Web Services. We can create virtual machines, virtual hard drives, even virtual IP addresses, all with just a few clicks. It also includes an S3-alike called Swift.

I worked purely on the software side, but the hardware is pretty cool too. Here's a pic that I hopefully will not get in trouble for posting. It's just too awesome not to brag about.

Posted Image

I used JuJu to deploy everything, which took care of most of the boring work of installing operating systems and configuring the software. There were still some kinks that I had to iron out manually. I only had to blow away everything and start over three or four times.

Every node in the cluster is monitored by Ganglia, which records CPU, disk, network, memory, even VM statistics. I highly recommend it; I even got it recording the datacenter temperature from a USB sensor with relatively little hassle.

There's also a Nagios server that periodically checks on the Ganglia metrics. We can set a threshold on any metric recorded by Ganglia and have Nagios send us an email when the threshold is exceeded. The only thing still missing is a GSM modem to allow Nagios to send us text messages if the internet connection dies.

Each day, a cron job on each of the three critical machines in the cluster fires up and rsyncs its entire hard disk on to an external RAID machine. I also set up a Nagios alert that fires if a backup fails or misses a day.


For some time now I've felt a tug in the back of my mind calling me to teach. WARNING: religion-speak ahead. In Christianity-land we call this "being led by the Spirit". For those unfamiliar with the lingo, it usually means "I want to do this thing, and it feels right, and there's nothing stopping me, so I'm pretty sure it's Spirit-led." (Side note: Christians spend way too much time trying to "discern God's will for my life." Just do your best, people.) (Side side note: I'm not cynical at all.)

So one day on my lunch break, I walked into my old middle/high school and said, "I'd like to teach a computer science class." They said, "can you start in a few weeks?"

In a few weeks I'm starting a teaching "trial run". It's a short, simple class, once a week for six weeks, mostly just to get kids excited about CS. If all goes well, Lord willing I'll probably start a more in-depth class next year. And oh man do I have some crazy ideas.

I was intrigued by an article on flipped classrooms, which go like this: watch lectures on YouTube at home, and do all your homework in class. Backward from the usual pattern. Here's why:
  • Lecturing is probably the least efficient form of teaching you could come up with, but it's often the only practical option for uploading information into people's brains. Recording the lectures on video at least mitigates some of the problems by allowing students to pause, fast-forward, or skip the entire lecture.
  • As a student, I never thought of good questions in class. They always came later that night (much later) when I pulled out the homework and hit a brick wall. By devoting the whole class period to homework, the teacher can maximize the time they have to answer questions.
  • The flipped classroom motivates students to participate in class, since they're already stuck there and it's in their best interest to finish their work quickly while they have access to the teacher.
  • I always studied alone, but most students work better in groups. This teaching model obviously encourages lots of collaboration.

This is all theory for me right now, but I'll let you know what I've learned a month or two from now. It's all very scary and new. Kids are going to be harder to program than computers, I think.

New Apartment

All I have to say is this:

Posted Image

Much more is happening. The next post will cover everything in Lemma. The project that simply will not die.

Mirrored on my blog

My Biggest Fear for the Future of Human-Computer Interfaces

Posted by , 17 March 2013 - - - - - - · 1,268 views
openstack, vim and 1 more...
I recently had to install and configure an 18-node OpenStack cluster, a process which involved a lot of SSHing and text-editing in terminals. I thought about learning Vim, but I was afraid of the incredibly steep learning curve, so I made do with GNU nano. It's not at all powerful, but it's easy.

Eventually I realized, "This is my job. This is what I do every day. Why am I holding off on learning something now, thinking it will slow me down, and that I'll have time to learn it later? It's not like I'm anticipating a major career shift any time soon."

With that in mind, I quit nano cold-turkey and moved to Vim. I won't waste time explaining why it's so great. There are already plenty of fantastic articles on that subject.

I'll just say this: Vim is powerful because it opens up a new interface to interact with your entire computer. Especially on Unixes, there's hardly anything you can't do with a shell and a good text editor. Which means you have one consistent interface that exposes everything on your computer.

Think of that. How many poorly designed, mismatched UIs do you use on a daily basis? Right now I have Chrome, Steam, Spotify, Windows Explorer, and Visual Studio open. I see about fourteen different UI paradigms cobbled together here. And, if I click in the lower-left corner, I get a completely disorienting context switch into an entirely different paradigm (that of the dreaded Metro tiles). I'm at the mercy of all these hapless UI designers.

Each one of those programs has a UI that I had to learn, each with their own quirks and bugs. Granted, Spotify and Chrome are both shining examples of UI design. I think they're about as good as it gets. Incidentally, web browsing and music organization are two things I will probably never do in a terminal.

Exceptions aside, it's incredibly empowering to be able to operate your computer on your own terms. And that brings me to my biggest fear for the future of human-computer interfaces:

There is no terminal in the cloud, or on mobile.

"That's good, right? CLIs are old and not at all user-friendly."

No argument there. But imagine for a second what a UI would look like if it had all the capabilities of a CLI with none of the cruft.
  • Again, it would provide one consistent interface between you and all your apps.
  • On the other hand, it would allow you to operate your apps on your own terms. Going with the analogy, right now you can choose one of 17 different shells and 5 text editors. Apache doesn't care what editor you used to configure it.
  • It would glue together all your applications, connecting them together however you want. In a CLI, that's accomplished with a single keystroke.
Compare that with current trends:
  • Cloud applications are the future of computing. Yet, to copy a picture from Facebook to Gmail, I still have to download the image, save it to disk, and upload it to another server. Most people don't have time to figure out how to do that.
  • Mobile applications, the uh, other future of computing, are notorious for not working with each other. Particularly on iOS, where the filesystem is almost completely opaque. On Android, it might as well be.
  • In both cases, each app has its own set of paradigms which do not relate to other apps at all.
The whole point of the internet is to connect things together through a common interface: HTTP and hyperlinks. These days, web apps have a single URL with a giant hashtag fragment appended. That breaks the interface. I can't write a script against that; I'd have to simulate user clicks.

"No you wouldn't, it's probably calling a RESTful API!"

Yes, the one shining light of hope is that every web app now has a nice, friendly, documented, open API. No, there are still major problems:
  • The main use of these APIs is still just identity. Great, I can connect my Facebook to my account on the pygmy llama forums I visit! Oh wait, all it does is save me the hassle of logging in all the time. I still can't have these two "apps" communicate with each other in any meaningful way.
  • Third-party clients are the other use-case. Great, I can choose between 3,000 different Twitter client apps! Oh wait, each one still only talks to Twitter and nothing else.
  • In the few instances where apps do talk to each other, it's only because the users bugged the developers enough for them to coordinate a common interface. The users can't operate their computer on their own terms. They're dependent on the developers to add this functionality.
Contrast this to command-line tools, where every program is designed from the ground up to work with other programs through common abstractions, most notably files and pipes, and where having a UI automatically entitles you to a scriptable API.

In short, open web APIs are good but not good enough. The question is, can we design an interface that has the power of a CLI with the user-friendliness of a GUI, and that is designed from the start for cloud and mobile environments?

If we don't, we will eventually lose control of our own computers; we'll be at the mercy of app developers.

Mirrored on my blog

March 2013 »