Adding a Metrics Cache to Descartes

2012-11-08 00:00:26 by jdixon

Update / TL;DR: Thanks to Bernd Ahlers (@berndahlers) for clueing me into the fact that you can call rufus-scheduler directly rather than indirectly through resque-scheduler. Because it uses Event-Machine, there's no need to run separate worker processes or queue up the jobs. Consider me sold. The changes have already been committed.

If you still want to read the original post, continue on.

Today I merged in a refactor of the Descartes bits that deal with metrics. Specifically, the live Metrics tab and sparklines view. This will have a profound effect on performance, but can also have a surprising effect on your wallet if you're not paying attention.

So, a little background on how Descartes used to operate and why this change was necessary. Not too long ago I added a new Metrics page that displays sparklines for every metric in your Graphite server and lets you click on them to create a composite graph. Although the page is still rather immature, it's useful for basic visualization and graph creation. Personally I think its major selling point right now is in the sparklines I mentioned. This is one thing that you don't really get with native Graphite -- being able to quickly see activity patterns on any metrics without going through the hassle of actually creating a graph. This is made that much more awesome by the presence of live filtering. Click on the Add to Graph button and you're presented with an additional input field that, as you type a string, will filter down the list of metric sparklines you're viewing in realtime.

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Cron As A Service

2012-02-11 10:35:19 by jdixon

I recently found myself in the need for a way to run a one-off Ruby script at scheduled intervals. As this is a work project I didn't just want to run it on my laptop or some random server. Turns out there's an easy way to run this for free on the Heroku Cedar platform without having to piggyback it on a "real" application. Because there are no web processes running, we'll be able to limit our dyno usage to a single dyno (in other words, it's free).

The script itself handles garbage collection duties for removing expired hosts off our beta account with Boundary. Basically I just want it to run every hour and cull anything that hasn't reported to their collectors in a day. For the purpose of this article the contents of the script are inconsequential, although I intend to present it fully in a future post.

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Trying to Get Shit Done

2012-02-09 23:38:00 by jdixon

This evening I asked for your suggestions on blocking online distractions, allowing me to focus on code for an extended period of time. I have a constant struggle with interruptions (read: shiny things) including online news, email and Twitter. There was a flood of responses in no time. Here are the more popular suggestions, along with my winners below.

  • quit the offending apps
  • block websites
  • login with a different user
  • work offline
  • coffee
  • music
  • self-control (lol rite)

I suspect that all of these would have some benefit, perhaps except coffee, which has never given me much of a boost anyways. As a side note, I've quit Diet Coke since my surgery and am exclusively drinking water. So it's possible that coffee might give me an insanely productive hit, but I'm not willing to tread that path yet. Here are the specific steps I took which seemed to work quite well for my particular workflow.

  1. quit Twitter app
  2. quit Chrome (primary browser)
  3. quit Firefox (used for HTML email, Facebook and banking)
  4. quit Propane (Campfire app, work communications)
  5. quit Adium
  6. quit Skype
  7. detached my remote screen session (mutt and irssi)
  8. equipped Sony MDR-V6 headphones
  9. launched Spotify radio (trance)
  10. put iTerm2 in full-screen mode (used for psql, git and debugging development server)
  11. put MacVim in full-screen mode
  12. launched Safari for API docs and development site

I'm pleased with the recent experiment, even if it only lasted one hour. I'll continue to make adjustments and report any significant improvements I find.

Sequel Migrations on Heroku

2011-11-30 10:39:02 by jdixon

I find myself using Sequel in conjunction with Sinatra these days to write more of my web applications. Never having been a fan of ORMs in general, and mostly comfortable with the ickier bits of SQL wizardry, it took me a while to warm up to the idea of using one for database migrations. But I've seen the possibilities with stuff like ActiveRecord. Being able to migrate my schema into a versioned state is "dee-lish".

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Achievement Unlocked: Heroku Operations

2011-07-11 11:59:56 by jdixon

I'm proud to announce that I'll be starting at Heroku in a couple of weeks. This is an exciting opportunity to work at a place that breathes DevOps and eats Infrastructure as Code. Whenever you hear someone describing "Platform as a Service", there's a good chance that Heroku will be the example they're talking about.

I first met Mark Imbriaco (@markimbriaco) when he was the Operations Manager at 37signals. Mark's a level-headed guy with a undeniable talent for Web Operations and an excellent track record for supporting his customers. It was no surprise to me when he took over as the Director of Cloud Operations at Heroku. Even after the acquisition by last December, they've continued to innovate at a breakneck speed (proof here, here, here and here).

Heroku development and operations teams get to work on the sort of rapid scaling and engineering challenges that pique my interest. I'm doubly excited to be able to share the fact that I'll be joining up simultaneously with Curt Micol (@asenchi) as the newest Operations Engineers on Mark's team. It's an odd coincidence that we're both big fans of BSD. Hopefully nobody holds that against us. ;-).

Needless to say I'm thrilled about the whole thing and hope that it gives me more cool stuff to write about here. Stay tuned.