Archive for April, 2009

Six-month cycles are great. Now let’s talk about meta-cycles: broader release cycles for major work. I’m very interested in a cross-community conversation about this, so will sketch out some ideas and then encourage people from as many different free software communities as possible to comment here. I’ll summarise those comments in a follow-up post, which will no doubt be a lot wiser and more insightful than this one :-)

Background: building on the best practice of cadence

The practice of regular releases, and now time-based releases, is becoming widespread within the free software community. From the kernel, to GNOME and KDE, to X, and distributions like Ubuntu, Fedora, the idea of a regular, predictable cycle is now better understood and widely embraced. Many smarter folks than me have articulated the benefits of such a cadence: energising the whole community, REALLY releasing early and often, shaking out good and bad code, rapid course correction.

There has been some experimentation with different cycles. I’m involved in projects that have 1 month, 3 month and 6 month cycles, for different reasons. They all work well.

..but addressing the needs of the longer term

But there are also weaknesses to the six-month cycle:

  • It’s hard to communicate to your users that you have made some definitive, significant change,
  • It’s hard to know what to support for how long, you obviously can’t support every release indefinitely.

I think there is growing insight into this, on both sides of the original “cadence” debate.

A tale of two philosophies, perhaps with a unifying theory

A few years back, at AKademy in Glasgow, I was in the middle of a great discussion about six month cycles. I was a passionate advocate of the six month cycle, and interested in the arguments against it. The strongest one was the challenge of making “big bold moves”.

“You just can’t do some things in six months” was the common refrain. “You need to be able to take a longer view, and you need a plan for the big change.” There was a lot of criticism of GNOME for having “stagnated” due to the inability to make tough choices inside a six month cycle (and with perpetual backward compatibility guarantees). Such discussions often become ideological, with folks on one side saying “you can evolve anything incrementally” and others saying “you need to make a clean break”.

At the time of course, KDE was gearing up for KDE 4.0, a significant and bold move indeed. And GNOME was quite happily making its regular releases. When the KDE release arrived, it was beautiful, but it had real issues. Somewhat predictably, the regular-release crowd said “see, we told you, BIG releases don’t work”. But since then KDE has knuckled down with regular, well managed, incremental improvements, and KDE is looking fantastic. Suddenly, the big bold move comes into focus, and the benefits become clear. Well done KDE :-)

On the other side of the fence, GNOME is now more aware of the limitations of indefinite regular releases. I’m very excited by the zest and spirit with which the “user experience MATTERS” campaign is being taken up in Gnome, there’s a real desire to deliver breakthrough changes. This kicked off at the excellent Gnome usability summit last year, which I enjoyed and which quite a few of the Canonical usability and design folks participated in, and the fruits of that are shaping up in things like the new Activities shell.

But it’s become clear that a change like this represents a definitive break with the past, and might take more than a single six month release to achieve. And most important of all, that this is an opportunity to make other, significant, distinctive changes. A break with the past. A big bold move. And so there’s been a series of conversations about how to “do a 3.0″, in effect, how to break with the tradition of incremental change, in order to make this vision possible.

It strikes me that both projects are converging on a common set of ideas:

  • Rapid, predictable releases are super for keeping energy high and code evolving cleanly and efficiently, they keep people out of a deathmarch scenario, they tighten things up and they allow for a shakeout of good and bad ideas in a coordinated, managed fashion.
  • Big releases are energising too. They are motivational, they make people feel like it’s possible to change anything, they release a lot of creative energy and generate a lot of healthy discussion. But they can be a bit messy, things can break on the way, and that’s a healthy thing.

Anecdotally, there are other interesting stories that feed into this.

Recently, the Python community decided that Python 3.0 will be a shorter cycle than the usual Python release. The 3.0 release is serving to shake out the ideas and code for 3.x, but it won’t be heavily adopted itself so it doesn’t really make sense to put a lot of effort into maintaining it – get it out there, have a short cycle, and then invest in quality for the next cycle because 3.x will be much more heavily used than 3.0. This reminds me a lot of KDE 4.0.

So, I’m interesting in gathering opinions, challenges, ideas, commitments, hypotheses etc about the idea of meta-cycles and how we could organise ourselves to make the most of this. I suspect that we can define a best practice, which includes regular releases for continuous improvement on a predictable schedule, and ALSO defines a good practice for how MAJOR releases fit into that cadence, in a well structured and manageable fashion. I think we can draw on the experiences in both GNOME and KDE, and other projects, to shape that thinking.

This is important for distributions, too

The major distributions tend to have big releases, as well as more frequent releases. RHEL has Fedora, Ubuntu makes LTS releases, Debian takes cadence to its logical continuous integration extreme with Sid and Testing :-).

When we did Ubuntu 6.06 LTS we said we’d do another LTS in “2 to 3 years”. When we did 8.04 LTS we said that the benefits of predictability for LTS’s are such that it would be good to say in advance when the next LTS would be. I said I would like that to be 10.04 LTS, a major cycle of 2 years, unless the opportunity came up to coordinate major releases with one or two other major distributions – Debian, Suse or Red Hat.

I’ve spoken with folks at Novell, and it doesn’t look like there’s an opportunity to coordinate for the moment. In conversations with Steve McIntyre, the current Debian Project Leader, we’ve identified an interesting opportunity to collaborate. Debian is aiming for an 18 month cycle, which would put their next release around October 2010, which would be the same time as the Ubuntu 10.10 release. Potentially, then, we could defer the Ubuntu LTS till 10.10, coordinating and collaborating with the Debian project for a release with very similar choices of core infrastructure. That would make sharing patches a lot easier, a benefit both ways. Since there will be a lot of folks from Ubuntu at Debconf, and hopefully a number of Debian developers at UDS in Barcelona in May, we will have good opportunities to examine this opportunity in detail. If there is goodwill, excitement and broad commitment to such an idea from Debian, I would be willing to promote the idea of deferring the LTS from 10.04 to 10.10 LTS.

Questions and options

So, what would the “best practices” of a meta-cycle be? What sorts of things should be considered in planning for these meta-cycles? What problems do they cause, and how are those best addressed? How do short term (3 month, 6 month) cycles fit into a broader meta-cycle? Asking these questions across multiple communities will help test the ideas and generate better ones.

What’s a good name for such a meta-cycle? Meta-cycle seems…. very meta.

Is it true that the “first release of the major cycle” (KDE 4.0, Python 3.0) is best done as a short cycle that does not get long term attention? Are there counter-examples, or better examples, of this?

Which release in the major cycle is best for long term support? Is it the last of the releases before major new changes begin (Python 2.6? GNOME 2.28?) or is it the result of a couple of quick iterations on the X.0 release (KDE 4.2? GNOME 3.2?) Does it matter? I do believe that it’s worthwhile for upstreams to support an occasional release for a longer time than usual, because that’s what large organisations want.

Is a whole-year cycle beneficial? For example, is 2.5 years a good idea? Personally, I think not. I think conferences and holidays tend to happen at the same time of the year every year and it’s much, much easier to think in terms of whole number of year cycles. But in informal conversations about this, some people have said 18 months, others have said 30 months (2.5 years) might suit them. I think they’re craaaazy, what do you think?

If it’s 2 years or 3 years, which is better for you? Hardware guys tend to say “2 years!” to get the benefit of new hardware, sooner. Software guys say “3 years!” so that they have less change to deal with. Personally, I am in the 2 years camp, but I think it’s more important to be aligned with the pulse of the community, and if GNOME / KDE / Kernel wanted 3 years, I’d be happy to go with it.

How do the meta-cycles of different projects come together? Does it make sense to have low-level, hardware-related things on a different cycle to high-level, user visible things? Or does it make more sense to have a rhythm of life that’s shared from the top to the bottom of the stack?

Would it make more sense to stagger long term releases based on how they depend on one another, like GCC then X then OpenOffice? Or would it make more sense to have them all follow the same meta-cycle, so that we get big breakage across the stack at times, and big stability across the stack at others?

Are any projects out there already doing this?

Is there any established theory or practice for this?

A cross-community conversation

If you’ve read this far, thank you! Please do comment, and if you are interested then please do take up these questions in the communities that you care about, and bring the results of those discussions back here as comments. I’m pretty sure that we can take the art of software to a whole new level if we take advantage of the fact that we are NOT proprietary, and this is one of the key ways we can do it.