Welcome to the second installment in Scrum for Operations, a series where I talk about (and go through) the process of doing systems work as part of a DevOps team according to the Scrum methodology. Last time, I introduced the basics of Scrum as it generally is used, and its key benefit of frequently delivering useful functionality. But I already hear the objections – “How can that turn out all right?” It is so light on process that one’s initial inclination is to dismiss it as “cowboy coding”, and we already know not to be “cowboy sysadmins,” right? One’s intuition might be (and mine was in the beginning, I’ll be honest) that this would lead to a metastable process that could not be sustainable without fundamental fatal flaws overtaking it.
Well, as I learned after trying to learn more and kicking the tires with our dev team here, there are several core disciplines that are agile’s saving graces.
We ops guys are used to testing being a neglected afterthought in the development process, often tossed over the wall to a QA team that isn’t well integrated into the product. Therefore we have a hard time trusting code that’s being handed over to us given our experience – we get it handed to us and it doesn’t work!
Well, agile pretty much understands that without pervasive testing, this kind of fast cycle process is doomed. At its extreme, some practitioners use Test Driven, aka Test First, development where failing tests must be written first and then code filled in behind it till the test passes. This creates a large inherent test framework.
Even agile groups that don’t do this almost always have metrics on unit test coverage and a required bar devs must hit. Here, our desktop software group that’s newly using Scrum has the mandate that “there must be XX% unit test code coverage or you’re not ready to ship.”
Similarly, acceptance testing (automated continuous testing of user stories vs the code) is a common part of agile. Continuous ongoing testing ensures quality through the dev cycle and reduces the need for time-intensive, and mysteriously always insufficient, big-cycle regression testing.
This is a great culture. And there’s all kinds of different tests – unit test, integration/functional/regression testing, performance testing, fault testing… Starting to get interesting to you? How about monitoring? In reality application monitoring is a special case of testing – it’s a “lightweight integration regression test.” Our initial approach to DevOps includes making test coverage goals for things like monitors and performance testing, because that plugs into the existing agile mindset well.
Bonus new terminology thing – the quick acceptance test you do upon release, which we always called “critical path testing,” is now being called “smoke testing” by the hip. Update your dictionaries!
A side note on formal QA groups. Just as we are working on DevOps, there has been previous work on how QA teams interact with agile dev teams, and there are a variety of different doctrines on how to split the work – often, it’s devs that are responsible for a lot of the testing. It’s a hard balance – you want the devs to be responsible for some of the testing because the best testing is “close to the code,” but just like with Ops, a real QA team has expertise beyond what a developer can just bolt in with 10% of their attention. Here, we have a dev team and also a remote QA team; devs test their own code on the daily build and then there’s a weekly push to a more stable environment where the QA team does acceptance testing and is moving into performance testing and the like.
Anyway, this endemic focus on testing and automation of testing and testing metrics is the pin that makes this agile flywheel actually turn without just flying off. (You are correct, some agile teams don’t do this – we call those “the unsuccessful ones.”)
And this is for you to do as well! There’s a whole post or series of posts in the topic “What does a unit test mean for something infrastructurey” – it is incumbent on you to figure it out and also have high test coverage with your work.
In general, agile dev is the epitome of horizon planning. You know you can’t get all the requirements ahead of time (or if you do get them all ahead of time, what you come out with won’t serve any real human’s need) and similarly preplanned architecture and design often doesn’t survive contact with the scrum. So it’s not “don’t plan or design,” but it’s “plan and design in an ongoing manner.”
This is one of the scariest parts for an ops person – we assume that we get one “bite at the apple”, and once we’ve set up the systems and let in the developers, we’ll never be allowed to change anything without a fight. But developers have this problem internally all the time – one dev is working on a core library or API that other developers are using, and they don’t wait for core guy to get done before they start. Instead, they have adopted a concept they call refactoring. Refactoring just means that each sprint, you are open to redoing fundamental stuff that needs to change (or that you realize you did kinda ghetto in the first place).
Because this is an accepted part of the iterative approach, you get to leverage this as well.First iteration they get the basic Tomcat and mySQL install out of the repo, and they can get started – and then in the second iteration you front it with Apache, or tune the DB for security, or whatnot and they have to make some changes to fit. I’m not promising no one will ever cry about this, but it’s a part of what makes the culture successful so it’s there for you to leverage.
And for you to adhere to! Be open to refactoring your infrastructure based on the emerging project needs.
A developer might not even mention this, and most books on agile don’t, because to them it’s so fundamental a discipline that it’s like breathing air. Sadly the same can not be said of Ops folks, so I’m mentioning it. When code is changed, it is in a shared source control repository – which gives other people on the group visibility into it (a collaboration touchpoint), is a common place to source it from (a deployment touchpoint), and can be used to easily manage multiple versions, even experimental ones, and merge or roll back changes.
This is the most fundamental empowering technology of modern software development (not just agile) and you must uptake it immediately or you have lost. Fair warning. It is the stepping stone that will allow subsequent Cool DevOps Automation to happen.
These three disciplines convert agile/Scrum from dangerous free-for-all to a new technique that gets your product done both more quickly and with higher quality than a waterfall method. I’ll talk further next time about how Ops slots into all this, and how you can fit your systems admin work into a Scrum mindset.
Also note, there’s some other agile disciplines surrounding agile design and encapsulation and patterns and whatnot, which I don’t understand well enough yet to speak authoritatively on. Feel free and chime in with other core disciplines if you are!