Sat, 07 Oct 2006
How to Waste a Day
I've been quite busy with school and work lately, so I was due for a day of unproductiveness. Here's how I wasted a nice Saturday:
Switch from Bloglines to Google Reader - After switching from straw to Bloglines a few months ago, I've tentatively switched to Google Reader as of today. One particularly nice feature is that it only marks posts as read when you've actually viewed them, rather than when you view the feed. It's also easy to create a link blog because you can share posts with a keystroke.
Fix Northern Trust Feed - I fixed my screen-scraped rss
feed of Northern
Trust research reports, which has been broken since around May I think,
when they updated their site.
Start Learning Lisp; Give up - I started reading Peter Seibel's book, Practical Common Lisp online, which
in turn, required that I start learning emacs. I got through about a chapter
and a half of the lisp book, and about half of the emacs tutorial before
deciding it wasn't worth the effort today.
Touch Base with the Housing Bubble - If you haven't heard, housing is
past the peak, and heading down.
I caught up on Mish's
blog, where the deflationary (rather than hyperinflationary) recession
looms large. And if you haven't met Casey
Serin yet, he's a 24 year-old facing forclosure five houses with $2 million
in mortgage debt. Bummer.
Sat, 09 Sep 2006
Restricting Mail Delivery Times with Exim
Denisa decided she doesn't want to feel compelled to check her email all day long, and asked me if there was a way to restrict the hours during which she could receive email. Since I use the magical MTA that is Exim, I was sure this must be possible. While I couldn't find explicit support for such a feature, I was able to hack something out. Here's my new local_delivery transport:
local_delivery:
driver = appendfile
envelope_to_add
file = /var/spool/mail/${local_part}
group = mail
mode = 0660
no_mode_fail_narrower
return_path_add
# hack to queue messages during certain hours
message_size_limit = ${if ! and {\
{match_local_part{$local_part}{+time_restricted_users}} \
{or {{<{${substr_11_2:$tod_log}}{21}}{>={${substr_11_2:$tod_log}}{22}}}} \
}{0}fail}
The trick I used was to force expansion failure of the message_size_limit when delivering a message to her address and when the current time matches our constraints, in this case before 9pm or after 10pm. The expansion failure causes the message to be queued. To ensure that she actually gets her queued messages during that one hour window, I added a new retry rule for our domain that retries every 15 minutes for four days, rather than the default rule which increases the interval between delivery attempts as the time on the queue increases. In case I ever want to configure other accounts similarly, I set up a localpartlist named time_restricted_users.
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Mon, 10 Jul 2006
Free Markets and Free Beer (IHS Summer Seminar)
I spent last week at Georgia Tech in Atlanta attending a seminar put on by the
Institute for Humane Studies. Although the
title of the seminar was Ideas &
Entrepreneurs, the focus was more generally classical liberal/libertarian thought. The
lectures on public
choice theory and political science by Georg Vanberg and law by John Hasnas
were particularly interesting. If you have the opportunity to take courses
with either of them, I'm sure they would be fantastic.
For any students interested in free markets, individual rights, limited government, etc., I highly recommend attending an IHS seminar. They brought together a great group of young, thoughtful people. They also provide free beer at a social every evening.
I gave a short presentation on inflation during a student panels session
at the seminar. We were quite constrained on time so I had to rush through a
lot of information, but I think I did fairly well considering the
circumstances.
Mon, 26 Jun 2006
Blosxom Static Rending with Lighttpd
To get more familiar with lighttpd, I've switch over the web server on this machine from apache to lighty. The most difficult part has been replicating my apache setup to serve static blosxom files.
My goal is to serve a static html file if 1) a static version exists, 2) the query string is
empty, and 3) the request is not a POST. Because I've switched from using the
blosxom writeback plugin for comments to Haloscan, I don't have to worry about the third
condition, but it would be nice to figure out a way to replicate
RewriteCond %{REQUEST_METHOD} !^POST [NC] with lighty.
Here's what I've come up with in my lighttpd.conf:
$HTTP["host"] == "xn.pinkhamster.net" {
server.document-root = "/www/xn.pinkhamster.net"
$HTTP["url"] =~ "^/blog" {
cml.power-magnet = server.document-root + "/power-magnet.cml"
}
# There's no content at http://xn.pinkhamster.net/ so redirect to /blog/
url.redirect = ("^/$" => "/blog/")
# I'm not using the writeback plugin anymore so rewrite any
# requests for writeback pages to the corresponding html page.
url.rewrite-once = (
"^/blog/(.+)\.writeback(\?.*|$)" => "/blog/$1.html$2",
)
# If there's not a static file served by the power-magnet, have blosxom
# serve the page.
alias.url = (
"/blog" => "/usr/lib/cgi-bin/blosxom",
)
cgi.assign = ( "blosxom" => "" )
}
In order to serve the static pages, we have to use the power-magnet feature. The power-magnet is a CML (Cache Meta Language) script which runs for each request. In this case, we only run it for requests that start with "/blog". CML is designed to improve web serving performance by serving cached, static pages when possible.
CML scripts are written in Lua. My check for
an empty query string doesn't work yet; I'm hoping to get some help on the
lighty mailing list. Update: I've updated the check for an empty
query string so it actually works. There was a logical error in my first
attempt, but neither get.maxn ~= nil nor get.maxn ~=
0 works. So now I just loop through the query string values and update
a counter if there are any. It's not very efficient, but it works. The rest
of the script just checks for either a static index.html file if the request
was for a directory or the static version of the requested page, and returns it
if it exists. Update 2: I've updated the power magnet script to
not have to loop through the get array.
-- if query string is empty and static file exists, serve static file
dr = request["DOCUMENT_ROOT"]
-- local f=assert(io.open(dr.."/debug.out","a"))
-- this doesn't work how i think it should
-- if get.maxn ~= nil then return 1 end
i = 0
for k,v in pairs(get) do
i = i+1
end
-- f:write("i = ",i,"\n")
if i ~= 0 then return 1 end
sn = request["SCRIPT_NAME"]
static = string.gsub(sn, '^/blog/(.*)$', '/static/%1')
if (file_isdir(dr .. static) and file_isreg(dr .. static .. "/index.html")) then
-- f:write("cache hit on directory\n")
output_include = { dr .. static .. "/index.html" }
return 0
elseif file_isreg(dr .. static) then
-- f:write("cache hit on file\n")
output_include = { dr .. static }
return 0
end
-- f:write("no cache hit\n")
return 1
Tue, 20 Jun 2006
Debian Virtual Private Server
I got a new virtual private server (vps) from a company called TekTonic today. I've been meaning to replace the Pentium MMX 200 that hosted this blog and my email for a long time. The virtual server is running within Virtuozzo, a commercial virtualization product, though the underlying technology is also available as the open source OpenVZ.
For $8 per month, I've got a virtual server running on a Dual AMD Opteron 246 with 128MB of RAM, 5GB of disk space, and 512kbps out (with unmetered inbound traffic). Since I had been running on an old piece of crap, I've already got everything set up to run fine within a small amount of memory. Apache is server mostly static pages from blosxom; Postman is my lightweight webmail application for the rare occassion when I need it; visitors for web stats; uw-imapd and exim (though I am using the heavy build with exiscan-acl) for mail; and the good old jabberd in case I ever find someone who uses jabber/xmpp. If I were running a database or some java application server, I'd need more ram.
The bandwidth is capped by the virtualization software which means you can't spike, but it also means no overage charges. TekTonic charges $50/month for an additional megabit which is pretty good.
They offer CentOS 4, Fedora Core 4, Suse 10.0, and Debian 3.1, and they had my Debian server provisioned in about 10 minutes.
I've only been running on the new server for about 7 hours, but so far, I'm very impressed. If you're reading this, the server is still up, so that's good.
Sat, 17 Jun 2006
Left-Handed Pens
A couple months ago on Digg, there was a post about putting a Mont Blanc refill in a Pilot G2 case. Some of the comments indicated that the G2 itself was a very good pen. So the last time I went to Wal-Mart, I tried out the G2, which is a gel ink pen. Unfortunately, it was not designed for left-handed writers. The ink takes way too long to dry, and if you attempted to write with it, you would end up with a page full of smudged ink. If you're one of those lefties who gives us a bad name by turning the paper perpendicular or even upside-down, perhaps you could make it work, but I'm not familiar enough with the acrobatics of that method of writing.
I must recommend that the left-handed stick with Pilot's Extra Fine (0.5) VBall Grip, the ink of which dries quickly enough to cause only the occasional gentle smudge.
On a related note, Mead sells left-handed notebooks which are just regular notebooks with the front and back covers swapped so it opens on left and you write on the page on the left with the spiral on the right. Although I'm a bit ashamed that it took seeing one of these notebooks to come up with the solution to spiral hand, I now open all of my notebooks from the "back" and write on the left page.
Blogs Need Pictures(?)
Russell says that blogs need pictures of their authors. I don't feel strongly one way or the other about it. I pretty much only read blogs in straw, so I don't see authors' mugs very often. For those that care, though, I've added my picture. The right side was pretty barren anyway.
Save the Date
My friend, Mike, is getting married later this year. I receive a "save the date" notice last week, followed by a second notice with a correction to the wedding's website.
I really don't understand the point of these notices. In order to send a save-the-date notificiation, you must already know when the wedding is, and if you know when the wedding is going to be, you almost certainly know where it's going to be held, especially if you're the type inclined to send out such notices. Furthermore, you know who you're going to be inviting because you wouldn't send a save-the-date notice to somebody who you aren't inviting. So, if you know all the critical details, why not just send out the invitations?
My hypothesis is that some couple actually had a legitimite need to send out such notices, such as an impending wedding date without a confirmed location. But some bachelorette received received one of these notices and decided her wedding had to have at least everything that her disorganized friend's did. And at some point, the stationer or wedding planner added save-the-dates to the checklist, and we'll be forever subject to such silliness until there is a cure to bridal irrationality syndrome.
Tue, 23 May 2006
Drunk Drivers Suck
We were rear-ended in a hit-and-run last night. The driver was apparently drunk. He hit us while we were driving about 35 mph on Washington Blvd in Culver City. We pulled over to the side of the road, and he floored it and took off. I then sped up to get his license plate number. We didn't have to pursue him for very long: he slammed into a parked car a few hundred meters from where he hit us, and we pulled over about 30 feet behind him.
I called the police, and while on hold, the driver got out of his car, and started walking towards us. Not wanting to confront a potentially violent drunk, I pulled in front of him. He got back in in his truck and sped off again.
The police arrived about 10 minutes later to take a report. Since there wasn't any damage to our car other than a little scratched paint and no injuries, the police officer asked if we really wanted to file a report. I wanted to make sure that we filed an official report in case we were needed as witnesses in the event of a subsequent vehicular manslaughter or something. If this guy didn't kill anybody last night, he got very lucky. Leaving the scene of an accident is also a crime, but unfortunately, he probably won't be prosecuted.
Overall, we were lucky not to have been hurt. I just hope the police can get this idiot off the road.
Sons & Daughters
Here's the video Fred Goss created to sell NBC/Universal on the idea of an improvised sitcom, which eventually turned into Sons & Daughters, the funniest show since Seinfeld, which was recently canceled after airing 10 episodes.
Fred has a blog on MySpace. He's considering doing an internet-distributed show, but it probably won't be Sons & Daughters because it'll probably be hard to scale down from the current 80-person crew/$700k-$1M per episode budget. Whatever he ends up doing, I'm sure it'll be hilarious.
