My first job was in Operations. When I got to be a Developer, I promised myself I’d remember how to be good to Ops. I’ve sometimes succeeded. And when I’ve been effective, it’s been in part due to my firsthand knowledge of both roles.
DevOps is two things (hint: they’re not “Dev” and “Ops”)
Part of what people mean when they say DevOps is automation. Once a system or service is in operation, it becomes more important to engineer its tendencies toward staying in operation. Applying disciplines from software development can help.
These words are brought to you by a Unix server I operate. I rely on it to serve this website, those of a few friends, and a tiny podcast of some repute. Oh yeah, and my email. It has become rather important to me that these services tend to stay operational. One way I improve my chances is to simplify what’s already there.
If it hurts, do it more often…
Another way is to update my installed third-party software once a week. This introduces two pleasant tendencies: it’s much…
- Less likely, at any given time, that I’m running something dangerously outdated
- More likely, when an urgent fix is needed, that I’ll have my wits about me to do it right
Updating software every week also makes two strong assumptions about safety (see Modern Agile’s “Make Safety a Prerequisite”): that I can quickly and easily…
- Roll back to the previous versions
- Build and install new versions
Since I’ve been leaning hard on these assumptions, I’ve invested in making them more true.
The initial investment was to figure out how to configure pkgsrc to build a complete set of binary packages that could be installed at the same time as another complete set. My hypothesis was that then, with predictable and few side effects, I could select the “active” software set by moving a symbolic link.
It worked. On my PowerPC Mac mini, the best-case upgrade scenario went from half an hour’s downtime (bring down services, uninstall old packages, install new packages, bring up services) to less than a minute (install new packages, bring down services, move symlink, bring up services, delete old packages after a while). The worst case went from over an hour to maybe a couple of minutes.
…Until it hurts enough less
I liked the payoff on that investment a lot. I’ve been adding incremental enhancements ever since. I used to do builds directly on the server: in place for low-risk leaf packages, as a separate full batch otherwise. It was straightforward to do, and I was happy to accept an occasional reduction in responsiveness in exchange for the results.
the Mac mini died,
I moved to
a hosted Virtual Private Server
that was much easier to mimic.
So I took the job offline to a local
VirtualBox running the same release and architecture of
to begin with,
now, both under
The local job ran faster by some hours (I forget how many), during which the server continued devoting all its I/O and CPU bandwidth to its full-time responsibilities.
Last time I went and improved something was to fully automate the building and uploading, leaving myself a documented sequence of manual installation steps. Yesterday I extended that shell script to generate another shell script that’s uploaded along with the packages. When the upload’s done, there’s one manual step: run the install script.
If you can read these words, it works.
DevOps is still two things
Applying Dev concepts to the Ops domain is one aspect. When I’m acting alone as both Dev and Ops, as in the above example, I’ve demonstrated only that one aspect.
The other, bigger half is collaboration across disciplines and roles. I find it takes some not-tremendously-useful effort to distinguish this aspect of DevOps from BDD — or from anything else that looks like healthy cross-functional teamwork. It’s the healthy cross-functional teamwork I’m after. There are lots of places to start having more of that.
If your team’s context suggests to you that DevOps would be a fine place to start, go after it! Find ways for Dev and Ops to be learning together and delivering together. That’s the whole deal.
Here’s another deal
Two weeks from today, at Agile Testing Days in Potsdam, Germany, I’m running a hands-on DevOps collaboration workshop. Can you join us? It’s not too late, and you can save 10% off the price of the conference ticket. Just provide my discount code when you register. I’d love to see you there.