A Concurrent Affair

The accident last week was the second time that I was involved in a car accident (it happened more often if you count cars hitting me on a bike).

The first time, a Houston rapper rear-ended my friend’s car, with my friend and me in it, and totaled it. He had an insurance card that he handed over, but what we didn’t know was that he had canceled the policy. He had had enough money to buy his new car in cash, but then he was too stingy to have the legally-required insurance.

You suck, man.

The accident last week wasn’t nearly as bad. Some people might not even care. There is some bent metal on the fender and a bunch of long scratches. The woman gave me her insurance card and her phone number. I talked to her insurance last week, but they didn’t get anywhere, because the phone number they had wasn’t working. I tried calling her, and it was the same number. She had given me a phone number that didn’t work.

That sucks too.

I tracked her down on Google and called her at work. I’m glad she honored my request to call her insurance as soon as possible. She acknowledged she was at fault, and now I can go get an estimate. She stunned me a little, though, when she grumpily said “I’m disappointed you got the insurance involved. I wish you had just gotten an estimate, and I would have paid for the repairs.” Tough luck, missy.

A co-worker of mine had the perfect response. He asked, “Did you say ‘I’m disappointed you hit my car’?” I wish I had.

At work, we deployed the latest version of our code on Wednesday night. It included a new query language. We used ANTLR to do the parsing.

We had never tested the new queries in a production setting, but the deployments to our Alpha, Gamma, and two regional clusters worked without problems. A few hours after deploying to the last clusters, a customer started using it, and that’s when all hell broke lose. I ended up rolling back to the previous version at 4 AM on Thursday.

A quick analysis by my coworkers yesterday showed that most of the time was spent doing the parsing.

The grammar that we used was essentially this one, which required backtracking by ANTLR:


E ::= ( E )
| C
C ::= ( E and E )
| ( E or E )


We never even let our test query finish, but it had been running for 45 minutes non-stop. I suggested a small change, which amounted to something like this:


E ::= ( E R
R ::= )
| and E )
| or E )


Sometimes it is helpful that I spent grad school in the programming languages group.

The parser that ANTLR generated now parsed our test query in under a second. Sure, we changed an LL(*) parser into an LL(1) parser, but I never would have thought that changing the grammar could result in an improvement by a factor of 2700.

via xkcd: Citogenesis.

Something similar actually happened with the Karl-Theodor zu Guttenberg, who used to be the German Minister for Economics and Technology and later the Minister of Defense, before it became clear that he had plagiarized his doctoral dissertation.

John McCarthy, Turing Award winner and one of the luminaries of computer science, died yesterday. I’ve spent the evening after the SPLASH Educators’ Symposium listening to McCarthy’s OOPSLA 2007 keynote speech (mp3).

Dick Gabriel introducing Stanford professor McCarthy's keynote at OOPSLA'07 in Montreal

John McCarthy was one of the earliest collaborators of my doctoral advisor, Robert “Corky” Cartwright. They worked on first-order programming logic in 1978 (Recursive programs as functions in a first order theory) and 1979 (First order programming logic).

McCarthy was on Corky’s committee. In Germany, the doctoral advisor is called “Doktorvater”, doctor father. If I haven’t quite lost a doctoral grandfather, I have at least lost a doctoral granduncle.

I wanted to check if I could squeeze another weekend of camping in this year, so I went to weather.com and typed in Mt. Rainier. It looked great: 23 Celsius on Saturday (73 Fahrenheit).

Mt. Rainier Weather

That did seem a bit odd, though, considering the temperature is hovering between 10 C (50 F) and 17 C (63 F) in Seattle. It turns out, that weather is for Mt. Rainier, Maryland, a suburb of Washington, DC. In Mt. Rainier National Park, WA, it’s snowing:

Mt. Rainier National Park Weather

Oops.

I lost my phone on the bus this morning. I stepped off the bus, went into a store, realized my phone wasn’t in my pocket, turned around and saw the bus drive away. Shoot.

I immediately changed my Google password, then upgraded my Lookout for Android to Premium so I could remotely lock my phone. I then began to track the phone and called the Seattle Metro. I could tell the customer service representative exactly where the bus with my phone was, but the representative said there was nothing he could do. I should try to catch the same bus when it comes back, or call them again tomorrow at 10:30 AM to contact Lost and Found. I tried to watch the bus, but I missed it, and I was at work, and that was more important.

Once, when I called my phone from my office phone, someone somehow picked up. I heard a women’s voice say “Oh-oh. Did you find that phone earlier?” Then there was a man’s voice saying “I can’t answer the call. It’s against the rules.”

Now, unfortunately, the phone’s battery is empty, and I can’t track it anymore. I don’t have a choice but to hope the bus driver found it and will take it to Lost and Found in the morning. The thing about it “being against the rules” makes me hopeful. I hope I had “Glueck im Unglueck” — that I got lucky in this misfortune.

Three logicians walk into a bar

I love it. This came to me from Spiked Math by way of Language Log, one of my long-time favorite nerdy blogs.

Last night, I registered for SPLASH 2011. I’ll only be there for the Educators Symposium and the Tuesday conference sessions, though. It was a bit of a tough call, but I figured taking vacation days for something I’m still passionate about is worth it.

Yesterday, September 23, was the last day of early registration pricing, and even though it was still September 23 here in the Pacific timezone, the server apparently was on Eastern time. On the website, I did not get the lower price, but Mandy Mann from Registration Systems Lab, the company operating the registration website, already promised an $80 refund in the middle of the night.

Thanks for working so hard!

I haven’t booked a hotel yet. I don’t think I’ll choose the conference hotel, though. I hope it won’t be too cold or rainy yet in Portland and that walking a mile or two won’t be too bad. Of course, I could drive that distance too, park at the conference hotel, and still get a better price.

I also renewed my 24 Hour Fitness membership today by two years. I was a bit skeptical when I signed up a year ago, but the gym membership has become something I do not want to miss anymore.

Update

I now booked my hotel through Hotwire for $69 a night. I had made good experiences with Hotwire in Portland when I stayed in the Courtyard by Marriot near the Convention center. Hotwire had a hotel with a similar rating and price now, but alas, it’s a different one. The Red Lion Hotel does not nearly look as good. Oh well…