My experiments with JRuby on Heroku have mostly been a bust.
I migrated a fairly simple 2.0.0 application over to JRuby, which didn't involve much other than switching to Kramdown from RedCarpet 2, and spending some time fucking around with my `database.yml` so the `activerecord-jdbc-postgresql` gem would actually connect.
But goddamn, the problems.
I let the JRuby 1.7.3 version of the application run for a little less than 24 hours, and in that time I got:
* about 6 hours of downtime spread sporadically throughout the period
* four or five "memory quota exceeded" at peak time, which didn't seem to do anything
* several random dyno crashes I wasn't seeing under Ruby 2.0.0, which were followed by...
* ...many, many "boot timeout" errors, which I never saw under 2.0.0 unless I had a bad configuration / initializer that was causing the app to crash
And those are just the critical errors. Performance across the board was crap: the New Relic comparisons from last week versus the switch to JRuby were pretty bad looking. Lots of request timeouts. Lots of request timeouts. And request throughput was apparently crap.
That last thing -- throughput -- bothers me almost as much as the random crits above. The setup is running puma, a threadsafe web server for Rack, so I was expecting to see much better request throughput than what I actually got. For those of you not in the know, JRuby has "real" threading, where-as Ruby MRI has a GIL and green threads, which means threading performance is not very good.
Switching to JRuby should have given me a real boost in throughput, but, unexpectedly, performance was piss-poor and there was a significant increase of request timeouts. The site's not getting _that_ much traffic, and the assets are stored on Cloudfront, so...
I don't have any idea what to make of this. Apparently the setup is working well for others (I don't see any complaints on Google, at least). But with such a simple setup on Heroku going sideways, I'm not sure what to make of it. Is it a bug in JRuby 1.7.3? A Heroku-specific problem?
Meh. I've redeployed on MRI, and the numbers are turning back to normal.
That concludes that experiment.
UPDATE 4/4/2013:
For curiosity's sake, I ended up chasing the source of the downtime to a bug in Kramdown not being able to deal with some erratically formatted content. The code doesn't throw an exception, it just... hangs, I guess. New Relic reports a ridiculously long runtime of 1.5 million milliseconds, but I'm not sure if that's because it actually takes that long to render, or something (probably Herkou) killed the process, and that's just how long it took. RedCarpet has no problems with the markdown in question, which explains why I wasn't seeing any problems before the switch to JRuby.
Wednesday, April 03, 2013
Monday, February 18, 2013
OS X 10.8 vs...
Fedora 18 / Gnome 3.6
Gnome 3.6 is very, very nice. It's not as refined as OS X yet, but you can see the Gnome team clearly closing the gap. The new lock screen is very nice and polished. Utilizing work-spaces is a snap. Gnome 3.6 has a very distinct, appealing style: once you open an application, there is little to no clutter. All you have is your app and the top bar showing you vital system information (battery life, wifi status, etc).The user interface is where the polish ends. As you'd expect if you've used any non-Ubuntu Linux distribution in the past few years, installing and updating applications is terrible. The built in method of installing applications from Fedora's repositories is awful; application packages (RPMs) you download from major vendors like Google (Google Chrome) have to be installed from the command line.
It's unfortunate such a pleasant user experience like Gnome 3.6 attached to an unpleasant way of managing applications.
Ubuntu 12.10 / Unity
Unity feels like a kind of forgotten Frankenstein's monster. HUD, the system for quickly selecting items in an application's menu, only works sometimes. The global menu bar suffers the same schizophrenia, leaving you with an overall inconsistent experience. When they work, they work beautifully. When they don't... well, meh.
The dash is nice and responsive, but often the search results hit the barn wall. Dash draws in search results from websites like Amazon.com, cluttering search results with unrelated items: searching for "photo" brings up Shotwell Photo Manager, as well as Birds of Prey, Kindle Fire HD, and what literally looks like a pornographic video. ... okay, no, it's apparently a smutty adult novel with a risque' cover. Still, not exactly what I was looking for, and definitely not what I want anyone to see if they're looking over my shoulder.
Installing applications is nice and straight-forward: the Ubuntu Software Center is a little sluggish, but search results are easy to browse. Installing applications from the Internet -- Google Chrome, Scrivener for Linux -- is straight-forward and very painless.
Unity needs a lot of shine, but seems promising.
* The Command button. I didn't understand how great this single button was until I started using it. Mac's have the standard Alt and Ctrl buttons, but the Command button is the primary modifier for interacting with applications. Command C always copies, Command V always pastes. Command W always closes a window, and Command T always creates a new tab. And because these keystrokes are divorced from the Ctrl key, you can actually copy and paste inside of a terminal window exactly the same as you'd copy and paste from a GUI application. The uniformity is great.
* Built-in gestures. You can summon application window overviews with a simple swipe, move between windows, open the notification panel, pinch and zoom... gestures don't feel like a tacked on feature. If Unity or Gnome 3 have a similar feature, they're hard to discover. OS X told me straight up during the setup procedure how to use the mulit-touch gestures.
* Coherent animations. When you download a file from Safari, the file's icon goes flying into the "downloads stack." When you minimize an application, you watch it disappear to its place on the dock. There's never any question of where a window went or a button just did. Most things in OS X have a nice, smooth animation that visually elaborates. It's thoughtful.
The dash is nice and responsive, but often the search results hit the barn wall. Dash draws in search results from websites like Amazon.com, cluttering search results with unrelated items: searching for "photo" brings up Shotwell Photo Manager, as well as Birds of Prey, Kindle Fire HD, and what literally looks like a pornographic video. ... okay, no, it's apparently a smutty adult novel with a risque' cover. Still, not exactly what I was looking for, and definitely not what I want anyone to see if they're looking over my shoulder.
Installing applications is nice and straight-forward: the Ubuntu Software Center is a little sluggish, but search results are easy to browse. Installing applications from the Internet -- Google Chrome, Scrivener for Linux -- is straight-forward and very painless.
Unity needs a lot of shine, but seems promising.
Errata
Some things I really like about OS X that have no Unity / Gnome 3.6 parallel.* The Command button. I didn't understand how great this single button was until I started using it. Mac's have the standard Alt and Ctrl buttons, but the Command button is the primary modifier for interacting with applications. Command C always copies, Command V always pastes. Command W always closes a window, and Command T always creates a new tab. And because these keystrokes are divorced from the Ctrl key, you can actually copy and paste inside of a terminal window exactly the same as you'd copy and paste from a GUI application. The uniformity is great.
* Built-in gestures. You can summon application window overviews with a simple swipe, move between windows, open the notification panel, pinch and zoom... gestures don't feel like a tacked on feature. If Unity or Gnome 3 have a similar feature, they're hard to discover. OS X told me straight up during the setup procedure how to use the mulit-touch gestures.
* Coherent animations. When you download a file from Safari, the file's icon goes flying into the "downloads stack." When you minimize an application, you watch it disappear to its place on the dock. There's never any question of where a window went or a button just did. Most things in OS X have a nice, smooth animation that visually elaborates. It's thoughtful.
Tuesday, February 05, 2013
Ruby: Ensure blocks can alter flow control!
This one bit me -- I've only found it documented in one place, here, but I also discovered the behavior after debugging a strange problem I was having with some command line processes not exiting properly when they received the exit command.
Basically, if you exit from an ensure block with "return" it behaves the same as if you had done a "rescue Exception" statement, which means it swallows up all exceptions, including exceptions raised to terminate the Ruby process when it receives SIGTERM, SIGQUIT, SIGINT, etc.
Basically, if you exit from an ensure block with "return" it behaves the same as if you had done a "rescue Exception" statement, which means it swallows up all exceptions, including exceptions raised to terminate the Ruby process when it receives SIGTERM, SIGQUIT, SIGINT, etc.
Sunday, September 16, 2012
FTL isn't a Roguelike -- or if it is, its a very bad one.
FTL was just released this week -- it's the space ship management game where you cut a swathe of destruction across the galaxy because something bigger and badder than you is doing just the same, nipping on your heels the entire time.
The game is pretty simple: you got crew inside your tiny tin-can cruising the galaxy. You got weapons, you got shields. You got systems the enemy can target on your ship to disable your shields, life support, steering, and you can do the same thing to them.
It sounds like fun, and it is, for awhile.
It purports itself to be a roguelike though, and that just ain't so. It is entirely too random to be a roguelike. In a roguelike, when you die, there's that moment where you go, "Why did I do that?"
You ask yourself "why did I do that?" because you understand that your character's death was totally avoidable. You could have checked the room you just entered more thoroughly. Maybe you were distracted and were just mashing one of the direction buttons, and your character walked over a trap or fell into a barely noticeable crevice to his doom. You could have totally looked at the frost giant in that next room (the one that killed you with one shot), decided you weren't ready, then turned around and went looking for better equipment, or a way around. Or maybe you just had to drink that unidentified potion because you are a freakin' lush and can't stop rolling the dice with your intestines on the line. In a roguelike, death sucks, but you did it to yourself, so while it is annoying, it rarely becomes too frustrating, because "how can I avoid that next time?" immediately follows. That's where some of the fun is.
FTL is the exact opposite of that. The game can and will literally set you up to fail; it is unavoidable and incredibly unfun. I'll go as far as to say that the game is more frustrating than fun once the charm wears off -- there is nothing like canting your head to side, staring at the screen and muttering "wtf?" because in the second sector you ran across an enemy that has 3 shields -- and you only have enough weapons power to fire 3 laser shots at a time. The game is structured in a way that you are either lucky or you are not. If you are lucky, you will come across some weak enemies, get some missiles and "drone" weaponry early on. If you are unlucky, you will barely scrape along, if you survive at all.
And barely scraping along is meaningless, as I found out the first time I made it the boss.
The boss had four shields, a laser cannon, a beam cannon, and something that fired at least 3 missiles every volley. I had four lasers shots a volley, an empty missile launcher, and a beam weapon that doesn't work if shields are up.
Despite the enemy ship being the size of a small planet, if I missed even /one/ laser shot, it would be impossible for me to damage the boss ship at all -- in FTL shields regenerate a few seconds after they've been depleted, leaving you with a very narrow opening. So in one volley you absolutely need to knock down all four shields with all four shots, or else you'll have to wait another 15 seconds to try again. If you miss one its a meaningless gesture; you can't damage the hull, so you can't destroy the ship.
So of course that's what happened: the game, having decided I would fail early on, let me struggle through to this last moment, where it put me in front of an enemy I had no way of beating.
You can only visit a handful of planets in a sector before the enemy armada starts blocking off the left side of the map, encroaching ever closer to your current position., You don't have the choice of sticking around and trying to scrap together as much "scrap" as you can get to afford new weaponry and crew members; you are either lucky, and on the journey to the sector's exit you got some easy scrap and nice weapons, or you are unlucky, in which case you will be unable to achieve victory.
Once I realized how the core of the game worked, I would be a few sectors in, less than halfway to the final showdown, and I'd look at the state of my ship and go "I'm not going to make it to the end." It's a realization that sucks the life out of the game, because there's nothing you can do to correct your course. You're screwed.
For a $9 game, I guess it was worth the 6 or so hours I got out of it, though.
The game is pretty simple: you got crew inside your tiny tin-can cruising the galaxy. You got weapons, you got shields. You got systems the enemy can target on your ship to disable your shields, life support, steering, and you can do the same thing to them.
It sounds like fun, and it is, for awhile.
It purports itself to be a roguelike though, and that just ain't so. It is entirely too random to be a roguelike. In a roguelike, when you die, there's that moment where you go, "Why did I do that?"
You ask yourself "why did I do that?" because you understand that your character's death was totally avoidable. You could have checked the room you just entered more thoroughly. Maybe you were distracted and were just mashing one of the direction buttons, and your character walked over a trap or fell into a barely noticeable crevice to his doom. You could have totally looked at the frost giant in that next room (the one that killed you with one shot), decided you weren't ready, then turned around and went looking for better equipment, or a way around. Or maybe you just had to drink that unidentified potion because you are a freakin' lush and can't stop rolling the dice with your intestines on the line. In a roguelike, death sucks, but you did it to yourself, so while it is annoying, it rarely becomes too frustrating, because "how can I avoid that next time?" immediately follows. That's where some of the fun is.
FTL is the exact opposite of that. The game can and will literally set you up to fail; it is unavoidable and incredibly unfun. I'll go as far as to say that the game is more frustrating than fun once the charm wears off -- there is nothing like canting your head to side, staring at the screen and muttering "wtf?" because in the second sector you ran across an enemy that has 3 shields -- and you only have enough weapons power to fire 3 laser shots at a time. The game is structured in a way that you are either lucky or you are not. If you are lucky, you will come across some weak enemies, get some missiles and "drone" weaponry early on. If you are unlucky, you will barely scrape along, if you survive at all.
And barely scraping along is meaningless, as I found out the first time I made it the boss.
The boss had four shields, a laser cannon, a beam cannon, and something that fired at least 3 missiles every volley. I had four lasers shots a volley, an empty missile launcher, and a beam weapon that doesn't work if shields are up.
Despite the enemy ship being the size of a small planet, if I missed even /one/ laser shot, it would be impossible for me to damage the boss ship at all -- in FTL shields regenerate a few seconds after they've been depleted, leaving you with a very narrow opening. So in one volley you absolutely need to knock down all four shields with all four shots, or else you'll have to wait another 15 seconds to try again. If you miss one its a meaningless gesture; you can't damage the hull, so you can't destroy the ship.
So of course that's what happened: the game, having decided I would fail early on, let me struggle through to this last moment, where it put me in front of an enemy I had no way of beating.
You can only visit a handful of planets in a sector before the enemy armada starts blocking off the left side of the map, encroaching ever closer to your current position., You don't have the choice of sticking around and trying to scrap together as much "scrap" as you can get to afford new weaponry and crew members; you are either lucky, and on the journey to the sector's exit you got some easy scrap and nice weapons, or you are unlucky, in which case you will be unable to achieve victory.
Once I realized how the core of the game worked, I would be a few sectors in, less than halfway to the final showdown, and I'd look at the state of my ship and go "I'm not going to make it to the end." It's a realization that sucks the life out of the game, because there's nothing you can do to correct your course. You're screwed.
For a $9 game, I guess it was worth the 6 or so hours I got out of it, though.
Saturday, September 08, 2012
Boobytrap your Monkey Patches!
If you are going to override an entire method with a monkey patch, at least do this:
raise "Make sure I'm still required!" unless Gem.loaded_specs["GEM_NAME"].version.to_s == "VERSION_THAT_REQUIRED_PATCH"
somewhere inside the file that does the monkey patching. Consider it a courtesy for everyone else, including yourself.
...
Okay, so I spent about 7 hours fiddle-fucking around with an inexplicable circumstance that came down to someone monkey patching an entire goddamn class by copying and pasting the Git HEAD version of that class so that an older version of the gem could use some of the newer version's functionality. Of course, 10 months later the underlying gem got upgraded way past the version the monkey patch came from, so a whole subset of functionality just broke "like magic!"
Devise: Logging in a user from a custom controller.
"Devise is a nightmare I have suffered only for the shining jewel called Omniauth clutched jealously within its thorny tentacles." -- a wild Arron under the influence of several frappucinos.
If you want to log in a user from a custom controller in Omniauth, this is your only hope:
user_params = params[:user] || {}
user = User.find_by_username(user_params[:username]) || User.find_by_email(user_params[:email])
if user && user.valid_password?(user_params[:password])
sign_in :user, user
else
# destroy the world.
end
You're probably thinking, "Can't I use warden.authenticate and cut down on the code and not have to do that nasty || at the beginning?"
No. See this question on StackOverflow for an explanation, but the short version is Devise doesn't want you to be able to use warden.authenticate anywhere outside of Devise::SessionController derived classes. Hilariously, if you go trolling for information on warden.authenticate you will find mostly unreplied to threads in Devise's Google Group, which is too many capitalized words in a row. If Google is a verb, can I refer to its products in lower case as well?
Goddamn. Does anyone remember Authlogic?
User#authenticate anywhere you wanted and you were fucking done, son. Yeah, Authlogic doesn't (or didn't) come with pre-built views like Clearance or Devise, which probably had a hand in it falling out of favor, but still, it was simple and almost impossible to screw up.
Theoretically you can get Omniauth up and running with anything, really, including Authlogic, but realistically setting up Facebook / Twitter login with Devise + Omniauth takes only seconds, and by the time you are screaming obscenities at your IDE it's too late to use anything else, assuming you even could -- I'm seeing that a lot of nifty stuff like rails_admin uses Devise under the hood.
Still hate the shit out of Devise for custom stuff, though.
That's right, hate. I am a mean coder. Rawr. Rawr!
Get out of here. Shoo.
Sunday, July 29, 2012
The Tablet Interface is coming to a PC near you: Thank God!
I absolutely cannot wait until tablet interfaces come to every operating system. I just spent the last 2 hours watching my mom fumble through Windows 7 shitty interface as I taught her how to copy files from "My Pictures" to "Dropbox."
I'm not even going to go into the whole "oh fuck, which cloud service do I tell her to use so she can easily back up her important photos" conversation I had in my head for like 10 minutes before that. On the desktop, all experiences are equally shitty; it ultimately came down to a matter of, "which service provided least friction."
It was Dropbox, of course; they ask for your name, an email address, and a password and then you're off to the races. She could manage that part on her own. Navigating through the files was a total pain, though, and I realized just how idiotic file manager interfaces are for regular every day computing. I mean, I'm a programmer, so I'm used to stuff being designed-by-stupid, but watching someone else struggle with these kinds of basic computing tasks is eye-opening.
The experience with Android + Dropbox is much easier. Smooth, intuitive for even someone who has no idea what they're doing.
Right then I realized that despite all the bitching about tablet interfaces, they do the Unix philosophy just right.
Each app does one thing, but each app does that one thing very, very well.
The Dropbox app? It lets you view and upload your Dropbox files. In a few clicks any file you want is uploaded or downloaded. It's that easy.
And, much like Unix pipes, integration is everywhere: anything that uses the standard "share" mechanism on Android can send a file to Dropbox. And Dropbox can send those files back using the "share" mechanism.
Tablet / Mobile interfaces like Android 4.0 are probably the best thing to happen in computing since... I don't know. All time?
I cannot wait until tablet interfaces come to PCs. Most of the savvy dudes and dudettes are going to turn them off because we need to get at the technical shit, but for everyone else? Kiss going over to your neighbors to show them how to send a file to their friend goodbye.
I'm not even going to go into the whole "oh fuck, which cloud service do I tell her to use so she can easily back up her important photos" conversation I had in my head for like 10 minutes before that. On the desktop, all experiences are equally shitty; it ultimately came down to a matter of, "which service provided least friction."
It was Dropbox, of course; they ask for your name, an email address, and a password and then you're off to the races. She could manage that part on her own. Navigating through the files was a total pain, though, and I realized just how idiotic file manager interfaces are for regular every day computing. I mean, I'm a programmer, so I'm used to stuff being designed-by-stupid, but watching someone else struggle with these kinds of basic computing tasks is eye-opening.
The experience with Android + Dropbox is much easier. Smooth, intuitive for even someone who has no idea what they're doing.
Right then I realized that despite all the bitching about tablet interfaces, they do the Unix philosophy just right.
Each app does one thing, but each app does that one thing very, very well.
The Dropbox app? It lets you view and upload your Dropbox files. In a few clicks any file you want is uploaded or downloaded. It's that easy.
And, much like Unix pipes, integration is everywhere: anything that uses the standard "share" mechanism on Android can send a file to Dropbox. And Dropbox can send those files back using the "share" mechanism.
Tablet / Mobile interfaces like Android 4.0 are probably the best thing to happen in computing since... I don't know. All time?
I cannot wait until tablet interfaces come to PCs. Most of the savvy dudes and dudettes are going to turn them off because we need to get at the technical shit, but for everyone else? Kiss going over to your neighbors to show them how to send a file to their friend goodbye.
Friday, May 25, 2012
KittyCaptcha works!
So, I've got a site I've got some problems keeping spam out of. I integrated with Akismet, which hits the barn wall as far as this site is concerned, and I also do a little bit of heuristics, based on poster location, amount of links / keywords in a particular piece of content, etc.
Akismet catches a lot of valid content as spam, so every few days I go through the spam bucket via the admin console and blindly white-list anything that doesn't look like spam. That was working OK for awhile.
Anyway, a few days ago I look and see that there are 163 identical bits of content, all of which completely skirted Akismet. Genius. It was obviously a bot. Now, part of this problem was that I had previously removed reCaptcha a few days ago as usability wise its terrible, and I actually failed a few of the reCaptcha tests myself because the scrambled words it presents are almost impossible to read these days.
So I figure, "Akismet will catch most everything, why use a captcha?"
As it turns out Akismet seems to catch very little, even when I'm marking items as spam. Even when things are *obviously* spam -- several dozen links, incredibly high keyword density -- it just completely misses the mark.
I rack my brain.
HashCash? No good implementation details, plus the concept hasn't been proved yet anywhere.
Simple math captchas? I hate math.
Then I remember way back when. A few years ago, people were talking about Microsoft Research's Assira and some random dude's KittenAuth. Neither caught on: Assira has good image breadth but looks like crap, and KittenAuth isn't very detailed regarding its implementation. Back then I initially dismissed it as a fruitless endeavor: where would you even get a large assortment of kitten pictures from? You'd have to partner with someone like Microsoft or come up with your own small batch of images that would quickly be "solved" by a human being paid 10 cents an hour.
But that was a long time ago. Now we've got Flickr, Instagram, Google Image Search. I have all the Internet's random kitten pictures at my disposal. I just need to use them to their fullest, cutest effect.
So I dig around, study some techniques on form signing with encryption, how to avoid replay attacks -- cracking the captcha once, by hand, then using it to resubmit over and over and over again ... -- and about 2 hours later I have a simple but adorable KittyCaptcha.
I deployed it into production last night, and haven't had a single drop of automated spam almost 24 hours later. Regular content is flowing through quite nicely.
This was a pretty poorly written post, I realize, but it's mostly stream of consciousness and I can't be bothered to go back and edit anything.
Akismet catches a lot of valid content as spam, so every few days I go through the spam bucket via the admin console and blindly white-list anything that doesn't look like spam. That was working OK for awhile.
Anyway, a few days ago I look and see that there are 163 identical bits of content, all of which completely skirted Akismet. Genius. It was obviously a bot. Now, part of this problem was that I had previously removed reCaptcha a few days ago as usability wise its terrible, and I actually failed a few of the reCaptcha tests myself because the scrambled words it presents are almost impossible to read these days.
So I figure, "Akismet will catch most everything, why use a captcha?"
As it turns out Akismet seems to catch very little, even when I'm marking items as spam. Even when things are *obviously* spam -- several dozen links, incredibly high keyword density -- it just completely misses the mark.
I rack my brain.
HashCash? No good implementation details, plus the concept hasn't been proved yet anywhere.
Simple math captchas? I hate math.
Then I remember way back when. A few years ago, people were talking about Microsoft Research's Assira and some random dude's KittenAuth. Neither caught on: Assira has good image breadth but looks like crap, and KittenAuth isn't very detailed regarding its implementation. Back then I initially dismissed it as a fruitless endeavor: where would you even get a large assortment of kitten pictures from? You'd have to partner with someone like Microsoft or come up with your own small batch of images that would quickly be "solved" by a human being paid 10 cents an hour.
But that was a long time ago. Now we've got Flickr, Instagram, Google Image Search. I have all the Internet's random kitten pictures at my disposal. I just need to use them to their fullest, cutest effect.
So I dig around, study some techniques on form signing with encryption, how to avoid replay attacks -- cracking the captcha once, by hand, then using it to resubmit over and over and over again ... -- and about 2 hours later I have a simple but adorable KittyCaptcha.
I deployed it into production last night, and haven't had a single drop of automated spam almost 24 hours later. Regular content is flowing through quite nicely.
This was a pretty poorly written post, I realize, but it's mostly stream of consciousness and I can't be bothered to go back and edit anything.
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