The economics of continuous deployment

time to read 4 min | 791 words

One of the things that I did, almost by accident, when we started Hibernating Rhinos was to create a CI server and a public daily build server. And every single successful build ended up in customer hands. That was awesome in many respects, it removed a lot of the “we have got to make a new release” pressure, because we were making new releases, sometimes multiple times a day.

When we started with RavenDB, it was obvious to me that this was what we were going to do with it as well, because the advantages to this approach as so clear. With RavenDB, we needed a two stage system, but still, every single build gets to the customer hands.

Awesome, great, outstanding, exceptional and other such synonyms. As long as you look at this from one angle, the one in which we are only concerned about the technical challenges of delivering software .The problem is that there are additional things to note here. Economic challenges.

Let us take the profiler as a good example. It was released in beta on the Jan 1, 2009, and since then we had 920 separate builds, adding a ton of new features, capabilities, improving performance, making things smoother and in general making it a better product.

That is over 3 years without a major release, mostly because we never had the need to do this, we kept delivering software on a day to day basis.

During that time, we delivered features such as viewing the result set, checking the query plan of a query (in all major databases), exporting the entire session to HTML so you can send it to your DBA, CI integration and so much more. It has been wonderful.

Except… this has one implications that I didn’t think of at the time. If you bought NH Prof on the 1st Jan, 2009 you got 3 years of product updates, for no additional costs. And unless we create a new major version, you can keep using the software, including all the updates and improvements, without paying.

That is great for the very early customers, but not so good for the people who need to eat so they can work on the profiler. Let us think about the implications of this a bit more, okay?

In order for us to actually make money, we have to:

  • keep expanding our one-off customer base, which is going to hit a limit at some point.
  • create a new version, getting the old customer to purchase the updates.

Seems simple, right? This is what most companies do, and how most software is sold. You get a license for version 1 and you buy a license for version 2.

So far, so good. But let us consider the implications of that. In order to get the old users to buy the new one, I have to put some really nice stuff in the next version. Which means that I have to do a lot of “secret” development because I can’t just release it on our usual continuous deployment mode. That sucks. And it also means that features that are already coded are actually disabled because we defer them to the next version.

So, the next version of the profilers is going to have to have some interesting features to get people to buy it. One of them is production profiling. It has actually been around for quite a while. It has simply been #ifdef’ed out of the product, because it is something that we keep for the next version.

I just checked, and I was acutely surprised by what I found. The initial work for production profiling was done in Jan 2010, it is working since then. I got side tracked with RavenDB so I never had the chance to actually complete the rest of the features for 2.x and release them all.

In mid 2010 we started experimenting with subscriptions. Instead of having a one time payment model, we moved to a pay as you go. So as long as you were using the profiler, you were paying for it, and in return, we provided all of those new features.

I have been thinking about this a lot lately. I strongly lean toward making the next version of the profiler (coming soon, and it will have a bunch of nice features) subscription only.

My current thinking it to allow two modes of buying the product. Monthly / yearly subscription and a one time fee that give you 18 months of usage (and doesn’t re-charge). That would allow us to keep producing software in incremental steps, without having to go away for a while and work in secret on big ticket features just so we can have enough stuff to put on “why you should buy 2.x” list.

I would appreciate any feedback that you may have.