Software Engineer

Jason Hancock

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I have been testing Redis at work getting familiar with the various modes of persistance. Usually I treat Redis like memcache and disable persistance, but we have a use case that requires us to persist the data. I started playing with the RDB and AOF files and stuff. One thing we wanted to test was how long it takes to load the files on startup with a large data set (large for us is 10GB or so).

puppetconf 2012

I’ve been at PuppetConf for the last couple of days. As usual, it has been an amazing experience and worth the price of admission. After seeing the presentations, I have a few things I’d like to explore when I get back to the office next week: Puppet 3.0 has been released (to the dev repos- hits prod repos on Monday apparently). Logstash rspec-puppet I want to get reinvigorated about the cloud Random tools Puppet3.

Let’s say you wanted to tie into Puppet’s inventory service from a PHP app. I wanted to do just that, so I started googling around to see if someone already done it. I found an Ubersmith plugin that had some code and a great writeup on generating the certificate, which I’ll paraphrase here. To generate a certificate called somecert on your puppetmaster, run this: puppet cert generate somecert cat /var/lib/puppet/ssl/private_keys/somecert.pem /var/lib/puppet/ssl/certs/somecert.

Inspired by this post from Oliver Hookins, I modified my puppetmaster’s apache configuration as described in the post (added the %D). Once I had some logs, I needed to parse them, but the script that Oliver wrote hasn’t been released. It isn’t pretty, but I threw together a quick perl script to get the job done. You can find it here.

I’m new to Graphite. From all the buzz on twitter and what I’ve gotten my hands on so far, it’s pretty cool. One of the problems (or features) is that Graphite has a great api, so quite a few third-party dashboards have popped up. Tasseo is one such dashboard. I like it for it’s minimalistic appearance that packs in just enough data to give you everything you need to know in a quick glance.

I’ve always been fascinated by photo mosaics. I suppose it goes back to the first time I saw one on a family vacation to Disneyland. They had photo mosaics throughout the park of the Disney characters that were made from the images that the cast members would take of families on vacation. Fast forward a few years (okay…maybe a decade and a half or thereabouts). I’ve dabbled a bit with photography and had built up a library of images about 40 or 50k deep.

I saw the post from the guys over at Metricfire about Building the Bit Red Button. I thought I’d build something similar as a proof of concept. Here’s what I ended up with: I used the same red dome button from SparkFun. Inside the case is an Arduino Uno that I repurposed from an earlier project. My dome button came equipped with an LED instead of an incandescent bulb, so I was able to power everything directly from the USB cable.

I host a couple of instances with Rackspace and generally go back and forth between them and AWS when I need an instance to do some testing. I was getting pestered by their emails every couple of weeks to check out their CloudU Certification program. I decided to check it out, but it’s unfortunate that I won’t get that 30 minutes of my life back. The program is set up as 10 lessons, each with a 10 question quiz at the end, followed by a 50 question final exam.


Puppetlabs released PuppetDB last Friday. It’s a drop-in replacement for the existing stored configurations backends and the inventory service. Stored configurations have always been a performance bottleneck in my puppet installations, so I was eager to try it out. I had it up and running, completely puppetized within a couple of hours. This was mainly due to my unfamiliarity with Postgres and having to repurpose some of the existing postgres modules on the forge to suit my needs.