Category Archives: devops

A Puppet User Trying Chef

Posted on by
6

I have a decent amount of experience at this point with puppet both from experience using it to manage the infrastructure running Fedora as well as setting it up at a pretty large scale at HubSpot.  But in a new gig, I decided it was worth rounding myself out a bit and giving chef a try.  Not out of any deep seated dislike of puppet but there are a few pieces that I’ve continued to run up against which are a little grating and so I figured it was worth broadening my horizons.  The nice thing is that both are fairly successful open source communities and realistically, as long as you’re using a system, you probably can’t go that wrong or switch in the future.

Side-note: I’ve also been playing with Michael Dehaan’s new project, ansible which is also interesting. But I don’t think it’s mature enough to use for a production environment yet and I also was mostly interested in it as a better remote execution layer as opposed to another full fledged config management tool. But yeah. It’s there.  It’s interesting. I’ll probably write more about it later.

With a little bit of chef time under my belt, I have to say that I’m not struck by drastic differences.  The terminologies are different, the DSL used on the config side is a bit different but they act pretty similarly and you can get either of them to do what you want.  That said, there are a few things (good and bad) that I’ve noticed about chef and figured I’d share for others who are looking at deciding for themselves.  Note that a few of the things in the dislikes section may well just be me missing something and being a n00b… suggestions welcome!

Things I’ve Liked 

  • Hosted Chef is a very very nice option to have.  Props to the Opscode team for building an infrastructure to run the server side for youand especially for making the barrier to entry nearly zero by letting you manage up to five hosts for free.  Given some of my headaches around running a puppetmaster previously, I’m glad not to be having to pull together everything to run a chef server
  • Knife is actually pretty cool.  I was skeptical before using it but it does a pretty nice job of encapsulating a lot of common tasks for you
  • Knife gets really cool with the addition of the ec2 plugin.  Launch servers, register them with hosted chef and have them ready to go.  I’ve built all of the surrounding bits and as the environment I’m dealing with grows, I think I’ll grow out of being able to use knife ec2 effectively, but it’s great for an easy starting point
  • Chef solo seems to work okay and have a few niceties over a master-less puppet setup but I didn’t spend much time with masterless puppet, so it’s probably just that I didn’t find the related nice pieces

Things I’ve Disliked / Been Annoyed By

  • The package support in the Fedora/CentOS/RHEL universe is pretty poor.  I realize that all the cool kids use Ubuntu these days but tons of server infrastructures are not.  Todd does a great job with the puppet (+ ecosystem) packages for Fedora and EPEL. Would love to see someone do similar for all of the Chef stuff
  • A lot of the cookbooks that are out there and published are Ubuntu specific. Even the ones which strive to work across distros often end up coercing the Fedora universe to look more like Debian.  Which isn’t necessarily a path I want to go down
    • Probably just a side effect of this but a lot of cookbooks using things which aren’t the standard init system (eg, depending on runit)
  • knife-ec2 makes you think you can get away with using it but I keep tripping across things it doesn’t support and making me consider abandoning it
  • Trying out cookbooks from others drives me crazy.  I’m pretty sure I’m missing the good workflow here but polluting my checkout by adding vendor branches and auto-committing things.  There’s gotta be something I’m missing here
So am I now a rabid chef fan?  Nope.  But it’s a nice system with some definite advantages for certain use cases.  I suspect I’ll find more of them as I use it more.

Graphing Jenkins Statistics

Posted on by

Like many people, we use Jenkins at work as our continuous integration server and we require that all changes that are committed go through being built in CI before they can get deployed.  Yesterday, someone asked if we could add another jenkins slave to try to reduce the amount of time spent waiting on builds.  While the slaves are fully puppetized and so it’s not much work to bring an additional slave online, my own anecdotal experience made me think that we weren’t really held up often in a way that additional slaves would help.  I had a vague memory of some graphs within jenkins so eventually found them but didn’t really find them that enlightening.  The scale is funky, it’s a weird exponential moving average and I just didn’t find it that easy to get any insight from them.

So last night, I sat down and wrote a quick little script to run via cron and pull some statistics and throw them into graphite.  Already with less than a day of data, I’m better able to tell that we end up with a few periods of about ten minutes where having more executors could help that are correlated with when someone does a commit to one of the projects at the base of our dependency tree.  So that gives us a lot better idea of whether or not the cost of an additional machine is worth the few minutes that we’d be able to save in those cases.

Since it didn’t look like anyone else had done anything along these lines yet, I put the code up on github.  There are a lot more stats that could be pulled out via the jenkins api, this is really just a starting point for what I needed today.

Velocity 2011

Posted on by

I spent last week out in California for the O’Reilly Velocity Conference.  It was in Santa Clara, which I hadn’t been to and frankly, I would be perfectly happy to not return.  Parts of California are nice, Santa Clara is an office building wasteland.  No good food options, nothing really going on, etc.  But I was there for a conference and not for other stuff, so it sufficed.

The conference was actually very good.  It has been a few years since I’ve been to a conference between grad school, my daughter being born, and being at a startup where conferences weren’t the priority.  But it was good to get back to it.  Had a lot of good hallway conversations with people about things that are relevant to us and saw a lot of good presentations.  And Velocity is especially relevant to me at this point as it was all about various web performance and operations stuff.  Where, unsurprisingly, there’s a lot of cool stuff going on.

I mostly kept to the more operations-y tracks just because they map better to what I’m currently working on.  I’ve come away with a bunch of things to look into and posted a whole bunch of choice quotes over on Twitter, but a few takeaways boiled down for here would include

  • If you’re using a public cloud provider, plan for things to fail.  Build your systems expecting it and you’ll have less pain.
  • HubSpot is doing an awesome job with post-mortems.  DanM actually posted a great blog post over on our dev blog about things we’ve learned from doing a lot of them.
  • Everyone complains and focuses on javascript performance but that’s misguided.  The bottleneck is the DOM.  Interestingly, none of the browser guys talked about that apparently
  • DevOps has mostly been about putting developers into ops (hi!) but also needs to be about putting ops into dev
  • Web performance has been very successful in tying itself to business metrics.  Weirdly, operations has overall been less successful at that
  • There’s a lot of work going on to help with debugging and working on webapps for mobile platforms.  Very cool.

None of those are particularly earth shattering revelations, but still good to see/hear.

Also, on Tuesday night I did a talk for the Ignite track.  So 5 minutes, 20 slides, auto-advancing.  My topic was “Just Too Late” and was largely around some things I’ve discovered transitioning into a role where I’m doing more ops stuff and the fact that I feel like I get to things too late.  But then turning it around and showing that’s not really so.  Stay tuned for a longer blog post on the topic.  But the talk went really well.  It was fun, a lot of positive feedback and was good for me to get back to it.  Looking forward to submitting some (full-length) proposals for talks for some conferences later this year.

I also had a few thoughts on the way conferences have changed since I last went to one

  • Twitter really is a pretty big game changer.  Lots of conversation on twitter during the conference about which sessions were good, useful tidbits from sessions, etc.  I actually felt that the experience was pretty strongly enhanced by it
  • Conference wireless still sucks.  But you can get decent data now for devices and avoid the use of the conference wireless entirely.  This made it easier to stay on twitter during the conference
  • An iPad (or other tablet) is a pretty perfect device for looking at stuff during a conference.  It sits on your lap so you can just check it sporadically, the battery lasts all day, you can get data from a cellular provider, and it’s reasonably fast.

Anyway, good time was had.  Thanks to all the people that I met and chatted up.  And hopefully it won’t be as long before I make it to another conference :-)

My new role

Posted on by

I’m still at HubSpot but my role within the company has changed a bit over the past few months.  Related to the article that Yoav wrote which was posted on onStartups today about how we’re trying to better empower our engineers and teams to really own things, I’ve shifted my focus some.

Instead of working on the product which is front and center to all of our customers or even working on the free tools at grader.com that millions of people use, I’m now instead focused quite a bit on various infrastructure related things for us. Obviously, I’ve done some of that all along, but at this point, it’s my primary job.

It’s a lot of fun. We are heavy users of EC2 and some of the other Amazon services. We also are using Rackspace Cloud some. And I wouldn’t be surprised if we add another provider in the future. So there is a challenge in making all of these environments look the same for the rest of our dev team as well as our on call folks.  We’re also working to make it so that we can easily continue to scale out as our compute needs increase.  All the sorts of things that I’ve spent some time thinking about over the years, but there’s no theoretical here — we’re really deploying, managing and everything else a pretty large distributed system. We are using a fair bit of open source stuff in addition to building some stuff ourselves.  The first thing was obviously ami-creator but there’s more to come almost certainly. In addition, we’ll probably be doing some work and submitting some patches to improve some of the tools and things that we use as it makes sense to do so.

And as we we are growing like crazy, I’m looking to hire some people to join my team to help us get even more things done. If I were writing a job description it would probably include bits and pieces like Linux administration, python, puppet, probably devops (as it’s something that’s in mind), cloud automation (… even though I still hate the word cloud), release and build tooling, monitoring, and more. Sound interesting? Drop me a line and let’s talk.