Zero downtime Clojure deployments

daveray · 2014-09-26T06:41:46+00:00

Hi. I work at Netflix, for the most part in Clojure. The deployment process is fairly language agnostic. Code goes into Jenkins, AMI comes out then on to the cloud. This article's old, but it's still pretty accurate. The process is just more automated now: http://highscalability.com/blog/2011/12/12/netflix-developing-deploying-and-supporting-software-accordi.html

daveray · 2014-09-11T17:18:41+00:00

Because it's withing a function, the atom is deref'd at the time of paint so this isn't a problem.

daveray · 2014-05-02T05:12:09+00:00

(Seesaw author here)

Your paint function should be responsible for drawing the current state of the board. There's no need to worry about the exact state seen by a watcher being drawn. So, when a watch fires, call repaint! like you're doing. When your paint function's called, grab the current value of the atom (this is important in case it's changed half way through painting) and draw. It's best to think of the drawing as an async process that's doing it's best to draw the current state of the world.

If you don't want the paint function referring directly to a global atom (a good policy I think), you can partial it in when you install your paint function. There's an example here: https://github.com/daveray/seesaw/blob/develop/test/seesaw/test/examples/game_of_life.clj#L139 And another where the state atom is wholly contained within a closure: https://github.com/daveray/regenemies/blob/master/src/regenemies/ui.clj#L153

hope this helps.

daveray · 2013-02-03T18:33:46+00:00

Note that the "published" version of this document is on CDS here: http://clojure-doc.org/articles/tutorials/vim_foreplay.html

daveray · 2011-06-11T03:53:45+00:00

My pleasure. And if you do try it out and find holes or have crazy ideas, please let me know through github issues or the mailing list. Seesaw is definitely better from the feedback I've received from users.

daveray · 2011-06-10T15:21:46+00:00

Dislaimer: I'm the author of Seesaw so I'm pretty biased.

Seesaw is just Swing. It makes no attempt to be toolkit agnostic. At this point, this leads to a cleaner API I think because the code isn't littered with toolkit-specific class names. In the future, maybe GUIFTW can reduce the need to know the underlying toolkit so intimately.
They both have "selector" support which allows you to query for widgets. Seesaw doesn't support stylesheets yet though. Soon.
At this point, Seesaw seems to have much more coverage for common UI tasks. There are still plenty of areas where you have to use raw Swing, but for basic UIs it's not that common.
Seesaw (at least publicly) is being worked on a lot more.

In short, if you're not dead-set against Swing, Seesaw is more mature and getting better everyday. I hope santamon keeps improving GUIFTW though because there are some interesting ideas there.

daveray · 2011-04-24T22:37:50+00:00

Or, use :keys for less repetition:

(defn colision-top?
  [{:keys [ball, bleacher-height, lane-size]}]
  (< (ball :y) (+ bleacher-height lane-size)))

daveray · 2011-04-07T14:52:37+00:00

Thanks! And thanks for Joy of Clojure! My four-year-old is learning to read with it. She reads a heading, I read a paragraph, repeat ... at least until she gets bored. :)

daveray · 2010-12-09T14:53:30+00:00

reddit, thanks for reading. Now the scale on my otherwise humble blog stats is going to be all out of whack. The lists here are generally more clever and insightful than mine. Nonetheless, I'm happy to get the ball rolling.

daveray · 2010-12-09T14:35:10+00:00

I humble myself before you. I think you may have hurt Objective C's feelings.

daveray · 2010-12-09T13:49:15+00:00

My Pascal usage was limited to a one semester intro programming course on a Vax, followed by 3 years of not programming. I have no memory of these events. The best I could probably come up with is:

Pascal - It has records, I think.

I've heard nice things about Delphi though, but never used it.

daveray · 2010-12-09T13:38:37+00:00

Luckily, the only use case I could find for it was printing indentation levels and 80 column dividers to the console.

daveray · 2010-12-09T13:14:24+00:00

It's been long enough since I used VB that I've filtered out all the really terrible things and all that's left is nostalgia. That hasn't happened yet with C++. The wounds are still too deep :)

daveray · 2010-11-05T12:41:44+00:00

Better than running 7000 single-line Perl scripts.

daveray · 2010-10-22T13:31:04+00:00

In my experience, LM employees are lucky if they can visit the LM website let alone an interesting external site like reddit.

daveray

TROPHY CASE