Archive for the ‘Database’ Category

Sustained IO on EBS == No Bueno

Wednesday, August 27th, 2008

I have a small EC2 instance running with a 25GB EBS volume attached. It has a database on it that I need to manipulate by doing things like dropping indexes and creating new ones. This is on rather large (multi-GB, millions of rows) tables. After running one DROP INDEX operation that ran all day without finishing, I killed it and tried to see what was going on. Here’s the results of the first 10 minutes of testing:

-bash-3.2# dd if=/dev/zero of=/vol/128.txt bs=128k count=1000
1000+0 records in
1000+0 records out
131072000 bytes (131 MB) copied, 0.818328 seconds, 160 MB/s

This looks great. I’d love to get 160MB/s all the time. But wait! There’s more!

-bash-3.2# dd if=/dev/zero of=/vol/128.txt bs=128k count=100000
dd: writing `/vol/128.txt': No space left on device
86729+0 records in
86728+0 records out
11367641088 bytes (11 GB) copied, 268.191 seconds, 42.4 MB/s

Ok, well… that’s completely miserable. Let’s try something in between.

-bash-3.2# dd if=/dev/zero of=/vol/128.txt bs=128k count=10000
10000+0 records in
10000+0 records out
1310720000 bytes (1.3 GB) copied, 15.4684 seconds, 84.7 MB/s

So the performance gets cut in half when the number of 128k blocks is increased 10x. This kinda sucks. I’ll keep plugging along, but if anyone has hints or clues, let me know. If this is the way it’s going to be, then this is no place to run a production, IO-intensive (100,000s and maybe millions of writes per day, on top of reads) database.

More Adventures in Amazon EC2 (and EBS)

Wednesday, August 27th, 2008

Short Version: You can find a fantastic video here about bundling customized AMIs and registering them with Amazon so that you can launch as many instances of your new AMI as you want. The video is so good that I don’t bother writing out the steps to do the bundling (it would be pretty darn long). These are some notes about launching an AMI, customizing it, and mounting an EBS volume to it (the video linked above doesn’t cover EBS). Also, check out the ElasticFox tool which is a very good GUI for doing simple EC2 operations. Nice if you’re just getting started or doing some simple tests.

There are two ways you can go about creating a custom machine image (AMI) for use with Amazon EC2: You can create an image locally by dd’ing to a file, mounting it with “-o loop” creating a filesystem on it, and bootstrapping the whole thing yourself, or you can grab an existing AMI that will serve as a “good enough” base for you to make your customizations, then bundle the customized image.

I’ll be talking about the latter option, where you identify a “good enough” image, customize it for your needs, and save that as your AMI. Unless you’re doing some kind of highly specialized installation, or are a control freak, you shouldn’t really need to start from scratch. I was just building a test image, and wanted a CentOS 5.2 base installation.

Here’s the command you can use to browse the AMIs you have access to (they’re either public, or they’re yours):

$ ec2dim -a

If that command looks funny to you, it’s likely because you’re used to seeing the really long versions of the AWS commands. Amazon also provides shorter versions of the commands. No, really - have a look! The long version of this command is:

$ ec2-describe-images -a

Too long for my taste, but it’s nice to know it’s there.

So, rather than start from scratch, I grabbed a base image that was close enough for my needs, and customized it. It’s a 5.1 base image, pretty well stripped of things that I don’t need, and a few that I do, but that’s ok. I’d rather start with less than more.

So step one is to launch an instance of the AMI I’ve chosen to be my ‘base’. Simple enough to do:

$ ec2run ami-0459bc6d -k ec2-keypair

And that’s pretty much it. It takes a couple of minutes (literally) for the machine to actually become available. You can check to see if it’s still in “pending” state or if it’s available by running ‘ec2din’. Without arguments, that’ll show you the status of any instances you have pending or runnning. Once the instance is running, you’ll be able to glean the hostname from the information provided.

An important note at this point: Don’t confuse “image” with “instance”. For the OO types in the crowd, an “image” is an object. It does nothing by itself until you instantiate it and create an “instance” of that object. For sysadmins, the “image” is like a PXE boot image, which does nothing until you boot it, thereby creating an “instance”.

The reason I used “PXE” and “object” in the above is because of the implication it makes: you can launch as many instances of an object as you want from a single object definition. You can boot as many machines as you want from a single PXE boot image. Likewise, you can launch as many Amazon EC2 instances from an image as you want.

So, in the time it took you to read those last two paragraphs, your instance is probably running. I now grab the hostname for my instance, and ssh to it using my keypair:

$ ssh -i ec2-keypair root@<hostname>

Now that I’m in, I can customize the environment, and then “bundle” it, which will create a new AMI with all of my customizations. With the instance in question, I installed a LAMP stack, and a few other sundry tools I need to perform my testing. I also ran “yum -y upgrade” which will go off and upgrade the machine to CentOS 5.2.

One thing I want to do with this instance is test out the process for creating an EBS volume. The two pieces of information I need to do this are the size of the volume I want to create, and the “zone” I want to create it in. You can figure out which zone your instance is running in using ‘ec2din’ on your workstation (not in your instance). I took that information and created my image in the same zone using the ‘ec2addvol’ command. If you don’t have that command on your workstation, then you don’t have the latest version of the Amazon command line tools. Here’s the command I ran:

$ ec2addvol -z us-east-1b -s 25

To see how it went, run ‘ec2dvol’ by itself and it’ll show you the status of all of your volumes, as well as the unique name assigned to your volume, which you’ll need in order to attach the volume to your instance. To do the ‘attachment’, you need the name of the volume, the name of the instance (use ‘ec2din’), and you need to choose a device that you’ll tell your instance to mount. Here’s what I ran (on my workstation):

$ ec2attvol -d /dev/sdx -i i-xxxxxxxx -v vol-xxxxxxxx

Now you can go back to the shell on your instance, mount the device, create a file system, create a mount point, add it to fstab, and, as they say in the UK, “Bob’s yer uncle”. By the time I wrote this post, I had already shut down my instance, but here are the commands (caveat emptor: this is from memory):

# mkfs.ext3 /dev/sdx
# mkdir /vol
# mount /dev/sdx /vol

If that all works ok, you can add a line to /etc/fstab so that it’ll be mounted at boot time, but I haven’t yet figured out how to attach a volume to an instance at boot time. The mount doesn’t work if you don’t attach the volume to the instance first. You’ll get a “device doesn’t exist” error if you try it. Clues hereby solicited. I assume I could probably use ‘boto’ and some Python code to get this done, but doing the same with a shell script wrapper around the Amazon tools might also be possible — but I don’t know how reliable that would be, because you’re at the mercy of Amazon and how they decide their tools should present the data (and *if* they provide the data you need for a particular operation down the road).

So now I have an EBS volume, and an instance. The volume is attached to the instance, and I can do things with it. I’m testing some database stuff, so I copied a database over to the volume, which was now mounted, so I could just ’scp mydb.tbz root@<instance>:/vol/.’

Once my database is there, I can attach it to pretty much whatever I want, which makes it nice, because I can test the same database, and the same database code, and see how the different size Amazon instances affect the performance, which gives me more performance data to work with. For production purposes, I’ll have to look more closely at the IO metrics, play with attaching multiple volumes and spreading out the IO, and I also want to test the ’snapshot’ capabilities. It’s also nice to know that if I needed to launch this in production (there are no plans to do so, but you never know), I could upgrade the database “hardware” more or less instantly :-D

If anyone has code or tools to help automate the management of all of this stuff, please send links! If I come up with any myself, I’ll most likely post it here.

Now that I have a customized AMI with all of my packages installed and my config changes made, I need to bundle this so that I can boot as many instances of this particular configuration as I want. An important note about bundling this *particular* image is that you MUST run ‘depmod -a; modprobe loop’ before bundling, since this process basically abstracts the manual process of bundling an image, which involves mounting a file as a volume, which requires a loopback mount.

The video I used to do the bundling is here, and if you can live through the disgustingly bad burps and chirps in the (Flash version) audio, it’s an excellent tutorial for bundling custom AMIs. While the process *is* pretty straightforward, it involves a number of steps, and the video goes through all of them, and it worked perfectly the first time through.

PyWorks Conference Schedule Posted

Wednesday, August 27th, 2008

Hi all,

The schedule for PyWorks has been posted! I’m really excited about three things:

1) there are some really cool talks that I’m looking forward to attending. There are a couple of sysadmin-related talks, AppEngine, TurboGears, Django, and an area I’ve been especially slow to move into: testing (I know, shame on me). There’s lots more so be sure to check it out.

2) the conference scheduling process is over ;-)

3) I get to meet a lot of people face-to-face that I’ve worked with in the past on Python Magazine developing articles, or interacted with on IRC, etc. One thing I like about conferences surrounding open source technologies is you get to thank people face-to-face for the sweat they poured into some of the tools I use regularly. Mark Ramm, Kevin Dangoor, Michael Foord, Brandon Rhodes, and a collection of Python Magazine authors will be speaking there, and other Python Magazine folks and generally familiar faces will be in attendance.

Enjoy!

For those still unaware, PyWorks will be held in Atlanta, Nov. 12-14, 2008. It’s sponsored by MTA, the publisher of Python Magazine, as well as php|architect. In fact, the php|works conference will be held simultaneously with PyWorks, and attendees of one are free to access talks in the other at will. There will also be a “center track” that will cover some more generic topics of interest to developers without regard to the language in use. Check it out!

Why I Don’t Write Book Reviews

Friday, August 8th, 2008

I have a lot of interaction with publishing types. I write a lot, and I edit some, and I do tech reviews and stuff for some publishers, and I co-authored a book, and I’ve worked on two magazines, and a newspaper, and I’m generally fascinated by the technical book market and stuff like that. I’m also someone who is lucky enough that his job is also his hobby. I work in technology, and am always doing something technology related at home in my spare time. Needless to say, I read tons upon tons of technical books.

I almost never post book reviews, in spite of the fact that I read all of these books. Why? Well, to be honest, I couldn’t tell you. It just hasn’t occurred to me to write a book review. Could be because I don’t really value book reviews too much myself I guess. I mean, if there’s a really obvious consensus across a huge number of reviews, I might be swayed. But in general, I find that book reviews are too often the target of astroturfing campaigns.

If there’s a tech book you’d like a review of that deals with things I’m generally into, let me know and I’ll post a review, if I’ve read it (or want to read it). Here are subjects I’m likely to have read books about in the past couple of years:

  • Linux, UNIX, and administration thereof
  • Python (all levels — I just read pretty much whatever is out there)
  • web 2.0 APIs (mostly Google and Amazon)
  • Any book about any service that can be run in a *x environment (DNS, Apache, DHCP, Jabber, and most other things that open a port)
  • Anything related to generic SQL, database design, or (more specifically) mysql and postgresql.
  • HPC (cluster computing)
  • Generic programming, software, computer science, or high-level systems design books
  • Digital photography (I have a Canon Digital Rebel, if that helps — I do *not* use Photoshop)
  • PHP
  • Maybe some other stuff I’m forgetting

The promise of Drizzle

Sunday, July 27th, 2008

I got to actually speak to Brian Aker for maybe a total of 5 minutes after his micro-presentation about Drizzle, which took place at the Sun booth at OSCON 2008. I was a bit nervous to ask what questions I had out loud, because the things I had wondered about were things I really didn’t see too much discussion about out in the intarweb. I’m happy to report that, if Brian Aker is to be considered any kind of authority (hint: he is), my ideas are not completely ridiculous, so maybe I’ll start talking a bit more about them.

UPDATE: lest anyone get the wrong idea, Brian Aker did, in fact, state that views are not on the short list of priority items for Drizzle, but he did say that views are one of the features he finds most useful, and that they’d probably be higher on any future priority list than, say, stored procedures. So, take my notes below about views with a grain of salt. It’s not necessarily “coming”.

My three ideas were these:

  1. Materialized views: my experience with views in MySQL is that they just plain old don’t scale well compared to other database systems I’ve used. I used Sybase in 2000 and views scaled better for me then than MySQL views do now, and I’m using them in mostly the same way (which is to say that I’m not using them to do evil things - I’m using them in the way most of the database community agrees they should be used). In the past, I thought materialized views were “nice to have”, but now that I’m working with much larger data sets, without a need for my reporting to be 100% real-time, materialized views would be great. To be honest, I win either way with Drizzle in all likelihood, as Brian Aker has proclaimed that views in Drizzle will not look like views in MySQL. He confirmed that materialized views would be a great thing to have a closer look at, and I was happy with that reply.
  2. “Query Fragments”: I didn’t know they were called query fragments. What I explained to Brian Aker was that I wanted to harvest subsets of cached result sets. So, for example, if I do a date range query (I do that a lot), and the result set is cached, and then my app does another query which is identical save for that the date range is a subset of the one in the cached result set, I’d like to grab that data from the cache. My actual question to Brian was “can this be built in such a way that this would be a reliable, trustworthy result coming from some middle tier component?” And that’s when he told me about query fragments. He said that this idea was not at all crazy, and was also worthy of further discussion.
  3. Vertical data-padding. Well… that’s what I’m calling it. Here’s the logic: I have lots of temporal data. Tons of it. My queries are largely things like “for this user, show me all of the foo’s bar’d — group by day — where day is between these two days”. MySQL is good at these kinds of queries (assuming you index well and, basically, that you’ve read “High Performance MySQL” a couple of times… per edition), but there’s something missing. When I get the result set back, any of the days for which no foo’s were bar’d, I don’t get a record. This is perfectly within the realm of reasonable behavior, but I’ve never known MySQL to let things like being reasonable get in the way of helping their users, so my suggestion was that MySQL, in order to do the comparisons for the “WHERE” clause, *MUST* know what dates fall within the dates in, say, a “BETWEEN” statement. It would then seem logical to have some way to tell MySQL “If one of those dates has no value, return a NULL” (or 0, or an empty string, or something). I don’t know the real name for this proposed feature, but I call it “vertical data-padding” because you’re padding columnar data, which, in my mind, is visualized vertically. Just like when you do a “GROUP CONCAT” or something, I would refer to that as horizontal data padding. I explained to Brian that one way I’ve seen this handled is to have a lookup table of static dates that gets joined to the main data table. You do a left outer join with the date lookup table on the left, and you get back a row for every date whether there’s data in the right-hand table or not. This works when ‘n’ is small (like everything else), but it’s hurrendous when you have, say, 10 million rows to deal with. Then you’re in what I call the “No Bueno Zone”. Brian seemed interested in the problem, and I’ll be discussing that with him further when his life settles down a bit (he’s been at OSCON, and he’s still settling in at Sun).

I want to thank Brian Aker for his enthusiastic attitude toward helping others, and for all of the work he pours into all of this stuff. I also want to say that, for me, Drizzle is really exciting, not so much because the feature set is more or less cherry picked to map onto what I do for a living, but also because it represents an opportunity to get ideas in the door before a lot of legacy cruft makes it impossible to implement these somewhat idealistic features without rocking the boat for the millions of users already launching it into production.

OSCON Day 2: Launching a Startup in 3 Hours

Tuesday, July 22nd, 2008

Launching a Startup in 3 Hours was a great talk given by Andrew Hyde (of techstars.org) and Gavin Doughtie (of Google). Both of the speakers are heavily involved in the recent trend of doing “Startup Weekends”, and techstars.org is an organization that hosts startup weekends all around the US (and I think internationally as well - Andrew mentioned one in Germany if I heard correctly).

The first half of the talk was about the general concept of a startup weekend, the problems it avoids (”we’ve been working for 9 months and haven’t launched anything”), the problems it brings up (”If you’re not using Java, you’re an idiot, so count me out!!”), and lots of details about how to organize, how to assign roles, and some common tools they use (like Basecamp and whatever your IM of choice is). There was also talk of legal issues, how (basically) to think about forming the company with the people involved, and decisions that need to be made at a business level aside from just the coding.
IMG_4514.JPG

The second half of the talk wasn’t a talk at all. Instead, people who had ideas stood up, presented their idea in a couple of sentences, and once the ideas were out there, we were told to break into groups and get to work! So people would get up and move over to the person whose idea they liked, and they’d start brainstorming. I decided to head out after about 30 minutes of observing and talking with people about ideas, but when I left, there were probably 6-8 groups of people engrossed in conversations, and the energy level was very high. Overall, it was a really exciting experience!

OSCON Evening 1 Begins, and More Portland Tips

Monday, July 21st, 2008

The evening plans didn’t wait for talks to be done. The IRC channel (#oscon on irc.freenode.net) was alive with talk of prospects for dinner and drinks after the conference. I myself was torn between a group going out for Lebanese and another going to Henry’s, but opted to go with my buddies from home to Henry’s.

It was worth it. If you haven’t been, Henry’s Tavern boasts 100 beers and hard ciders on tap (oddly, the beer list is the only menu *not* online - guess it changes too frequently). There are a ton of local beers that you can’t even get on the east coast just waiting for you to try, but there are also some rare treats, like the Belgian Lambic beers, which you don’t often see on tap. The food is a little pricey, but is really good, and the staff is very friendly. IMG_4491.JPGA couple of us were in a rush to get back by 7 for the BoF sessions, and when we asked the waittress how easy it was to catch a cab, she immediately informed us that she would have the hostess call one for us. About 2 minutes later we were in a cab on our way back (we wouldn’t have made it back in time if we had to walk back to catch the light rail).

I was not one of those rushing to a BoF, so I did a little poking around the area near the convention center. It was getting dark, and I didn’t want to stray too far, but I did find a couple of points of interest. First, there’s a bank right across the street from the convention center. I’d be willing to bet that the ATM there is less than the $3 the ATM inside the center charges.
IMG_4501.JPG
Beyond that is a paintball place. It was closed by the time I found it, and I don’t know if they run every day, or anything else, but interested parties might find it open during the lunch breaks or something if you wanted to check it out. The paintball place is located behind a building that is directly across the street from the conv. center. If you see the bank, it’s on the other side of the side street the bank sits on.

Tonight appears to be low-key from what I can tell. There’s currently no chatter on irc, the hotel bar had a few people chatting, and I might go down to catch the rush of people as they return from dinner and BoF sessions. Stay tuned tomorrow for more!

OSCON Day 1 Comes to a Close

Monday, July 21st, 2008

I think I have pictures of most of the basic parts of the conference at my OSCON Flickr set, and I thoroughly enjoyed day 1 of the conference. Of course, while *day* 1 is over, *night* 1 has yet to even begin. There are lots of BoF sessions, and maybe even more smaller meetups going on, as smaller groups take to discussing things over dinner and a beer or three.

I have to say, that I occasionally pop into irc channels for conferences I’m not even at and follow up on that because I’m involved a bit in conference planning as part of my work with Python Magazine (I’m helping to organize the PyWorks conference in November). This conference seems to have a pretty happy audience, if IRC chatter is any indication (and it usually is). Sure, there are a couple of weak spots in the wireless network, there are some fuzzy projectors, and there was a little confusion regarding breakfast this morning, but the important bits have been well-covered by the OSCON organizers and the “boots on the ground” here on site. Kudos to them all.

This afternoon I hopped to a couple of different talks: one on Memcached and MySQL, and the other on A/B testing. Both contained good content. Of course, I’m a systems guy primarily, so I sort of wanted more of an overview of memcached from the point of view of an admin who is deploying it rather than a developer implementing their code around it. I still got plenty of value out of that talk, and this *is* really more of an open source *developer’s* conference, so the expectations of 99% of the people in the room were met, I’m sure.

A/B testing is just not an exciting topic, and I would imagine that peoples’ bosses made them go to that talk whether they liked it or not. Not to say the talk wasn’t good - the parts I saw (I came in after the break) were good, and I learned from it, and that was the goal. If you’re a QA/QC person, I’m sure the talk was riveting, and there were a lot of good ideas and things I’d never considered flying by in the slides.

Overall, Day 1 is a win. I’ll cover more about this evening’s events in the pre-breakfast hours tomorrow. Stay tuned!

Day 1 of OSCON Begins, and More Tips for Conference-goers

Monday, July 21st, 2008

I got an early start. Too early. But I’m from the west coast, so my body thinks I slept in. I wandered around a bit, took a few pics which you can see at my Flickr OSCON set, and I discovered a couple of things that might be of interest:

  • The starbucks in the conference center charges over $2 for a small cup of joe. There’s a starbucks right across the street (you can see it from the breakfast area - seriously, it’s 5 seconds away), and they charge less than $2 for a medium (grande). That’s less than I pay at home.
  • The ATM outside the starbucks charges $3 for cash. I’ll report back when I find a cheaper one, but most places seem to take plastic here.
  • Every computer involved in this conference, from registration to the video screens that dot the common areas, are running Windows XP. Just sayin’.
  • The light rail system is free to go just about anywhere except for the airport, so there’s no excuse not to get out and see Portland and take in the food and beer and stuff.
  • For beer-lovers, not only is there the Oregon Brewers Festival starting at the tail end of this conference, but there’s apparently another festival that we missed *last* weekend!! Keep that in mind when you’re planning to come to OSCON next year.

Useful stuff - 2008 - first half

Friday, July 11th, 2008

Having a Google account is sometimes useful in ways you hadn’t planned for. For example, at a few different employers I’ve been at, I’ve had to prepare for reviews by providing a list of accomplishments to my supervisor. One decent tool for generating this list is email, though it can take some time. Another useful tool is the Web History feature of your Google account.

Though this isn’t necessarily indicative of everything I’ve accomplished in the first half of 2008 per se, it’s definitely indicative of the types of things I’ve generally been into so far this year, and it’s interesting to look back. What does your Web History say?

  • Gearman - this is used by some rather large web sites, notably Digg. It reminds me a little of having Torque and Maui, but geared toward more general-purpose applications. In fact, it was never clear to me that PBS/Maui couldn’t actually do this, but I didn’t get far enough into Gearman to really say that authoritatively.
  • How SimpleDB Differs from a Relational Database - Links off to some very useful takes on the “cloud” databases, which are truly fascinating creatures, but have a vastly different data management philosophy from the relational model we’re all used to.
  • Reblog - I found this in the footer of someone’s blog post. It’s kinda neat, but to be honest, I think you can do similar stuff using the Flock browser.
  • Google Finance APIs and Tools - did I ever mention that I had a Series 7 & 63 license two months after my 20th birthday? I love anything that I can think for very long periods of time about, where there’s lots and lots and LOTS of data to play with, where you can make correlations and answer questions nobody even thought to ask. Of course, soon after finding this page I found the actual Google Finance page, which answers an awful lot of potential questions. The stock screener is actually what I was looking to write myself, but with the data freely available, I’m sure it won’t be long before I find something else fun to do with it. I’m not a fan of Google’s “Feeds” model, but I’ve dealt with it before, and will do it again if it means getting at this data.
  • Bitpusher - it was recommended to me as an alternative to traditional dedicated server hosting. Worth a look.
  • S3 Firefox Organizer - This is a firefox plugin that provides an interface that looks a lot like an FTP GUI or something, but allows you to move files to and from “buckets” in Amazon’s S3 service.
  • Boto - A python library for writing programs that interact with the various Amazon Web Services. It’s not particularly well-documented, and it has a few quirks, but it is useful.
  • OmniGraffle - A Visio replacement for Apple OS X. I like it a lot better than Visio, actually. It has tons of contributed templates. You shouldn’t have any trouble making the switch. A little pricey, but I plunked down the cash, and have not been disappointed.
  • The Python Queue Module according to Doug - Doug Hellmann’s Python Module of the Week (PyMOTW) should be published in dead tree form some day. I happen to have some code that could make better use of queuing if it were a) written in Python, and b) used the Queue module. I was a little put off by the fact that every single tutorial I found on this module assumed you wanted to use threading, which I actually don’t, because I’m not smart enough…. though the last person I told that to said something to the effect of “the fact that you believe that means you’re smart enough”. Heh.
  • MySQL GROUP modifiers - turns out this isn’t what I needed for the problem I was trying to solve, but the “WITH ROLLUP” feature was new to me at the time I found it, and it’s kinda cool.
  • Wordpress “Subscribe to Comments” plugin - Baron suggested that it would be good to have this, and I had honestly not even thought about it. But looking around, this is the only plugin of its kind that I found, and it’s only tested up to WP 2.3x, and I’m on 2.5x. This is precisely why I hate plugins (as an end user, anyway. Loghetti supports plugins) ;-)
  • Lifeblogging - I had occasion to go back and flip through some of the volumes of journals I’ve kept since age 12, wondering if it might be time to digitize those in some form. I might digitize them, but they will *not* be public I don’t think. Way too embarrassing.
  • ldapmodrdn - for a buddy who hasn’t yet found all of the openldap command line tools. You can’t use ‘ldapmodify’ (to my knowledge) to *rename* an entry.
  • Django graphs - I haven’t yet tried this, because I’m still trying to learn Django in what little spare time I have, but it looks like there’s at least some effort towards this out there in the community. I have yet to see a newspaper that doesn’t have graphs *somewhere* (finance, sports, weather…), so I’m surprised Django doesn’t have something like this built-in.
  • URL Decode UDF for MySQL - I’ve used this. It works really well.
  • Erlang - hey, I’m game for anything. If I weren’t, I’d still be writing all of my code in Perl.
  • The difference between %iowait in sar and %util in iostat - I use both tools, and wanted the clarification because I was writing some graphing code in Python (using Timeplot, which rocks, by the way), and stumbled upon the question. Google to the rescue!
  • OSCON ‘08 - I’m going. Are you going? I’m also going to the Oregon Brewers Festival on the last day of OSCON, as I did in ‘06. Wonderful!
  • Explosion at one of my hosting providers - didn’t affect me, but… wow!
  • hypertable - *sigh* someday…when there’s time…
  • Small-scale hydro power - Yeah, I’m kind of a DIYer at heart. I do some woodworking, all my own plumbing, painting, flooring, I brew my own beer, I cook, I collect rain in big barrels, power sprinklers using pool runoff to give my lawn a jumpstart in spring… that kind of stuff. One day I noticed water coming out of a downspout fast enough to leap over one of my rain barrels and thought there must be some way to harness that power. Sadly, there really isn’t, so I did some research. It’s non-trivial.
  • You bet your garden - I also do my own gardening and related experiments.
  • RightScale Demo - WATCH YOUR VOLUME - a screencast showing off RightScale’s features. Impressive considering the work it would take me, a lone admin, to set something like this up. The learning curve involved in effectively/efficiently managing/scaling/monitoring/troubleshooting EC2 is non-trivial.
  • Homebrew Kegerator - Maybe if this startup is bought out I can actually afford this thing to put my homebrewed beer in. The 30-year-old spare fridge in the basement is getting a little… gamey.
  • The pound proxy daemon - I use this. It works well enough, but I’ve crashed it under load, too. I’ve also had at least one hosting provider misconfigure it on my behalf, and I had to go and tell them how to fix it :-/
  • Droid Sans Mono - a fantastic coding font. Installing this font is in my post-install routine for all of my desktops.
  • Generator tricks for systems programmers - David Beazley has made available a lot of Python source code and presentation slides from what I imagine was a great talk (if you’re a systems guy, which I am).
  • The Wide Finder Saga - I found this just as I was writing Loghetti. There are still some things in Mr. Lundh’s code that I haven’t implemented, but it was a fantastic lesson.
  • Using gnu sort for IP addresses - I’ve used sort in a lot of different ways over the years… but not for IP addresses. This is a nice hack for pulling this off with sort, but it doesn’t scale very well when you have millions of them, due to the sort utility’s ‘divide and conquer’ method of sorting.
  • Writing an Hadoop/MapReduce Program in Python - this got me over the hump.
  • Notes on using EC2/S3 - This got me over some other small humps
  • BeautifulSoup - found while searching for the canonical way to screen scrape with Python. I’d done it a million times in Perl, and you can do it with httplib and regex and stuff in Python if you want, but this way is at least a million times nicer.

Well, that’s a decent enough summary I guess. As you can see, I’ve been doing a good bit of Python scripting. Most of my code these days is written in Python instead of Perl, in part because I was given the choice, and in part because Python fits my brain and makes me want to write more code, to push myself more. I’ve also been dealing with things involving “cloud” computing and “scalability” — like Hadoop, and EC2/S3. I haven’t done as much testing of the Google utility computing services, but I’ve used their various APIs for some things.

So what’s in your history?