The Shape of Code

The Cloud looks like the next dominant platform for hosting applications.

What can a Cloud vendor do to lock customers in to their fluffy part of the sky?

I think that Microsoft showed the way with their network server protocols (in my view this occurred because of the way things evolved, not though any cunning plan for world domination). The EU/Microsoft judgment required Microsoft to document and license their server protocols; the purpose was to allow third-parties to product Microsoft server plug-compatible products. I was an advisor to the Monitoring trustee entrusted with monitoring Microsoft’s compliance and got to spend over a year making sure the documents could be implemented.

Once most the protocol documents were available in a reasonably presentable state (Microsoft originally considered the source code to be the documentation and even offered it to the EU commission to satisfy the documentation requirement; they eventually hire a team of several hundred to produce prose specifications), two very large hurdles to third party implementation became apparent:

• the protocols were a tangled mess of interdependencies; 100% compatibility required implementing all of them (a huge upfront cost),
• the specification of the error behavior (i.e., what happens when something goes wrong) was minimal, e.g., when something unexpected occurs one of the errors in windows.h is returned (when I last checked, 10 years ago, this file contained over 30,000 identifiers).

Third party plugins for Microsoft server protocols are not economically viable (which is why I think Microsoft decided to make the documents public, they had nothing to loose and could claim to be open).

A dominant cloud provider has the benefit of size, they have a huge good-enough code base. A nimbler, smaller, competitor will be looking for ways to attract customers by offering a better service in some area, which means finding a smaller, stand-alone, niche where they can add value. Widespread use of Open Source means everybody gets to see and use most of the code. The way to stop smaller competitors gaining a foothold is to make sure that the code hangs together as a whole, with no relatively stand-alone components that can be easily replaced. Mutual interdependencies and complexity creates a huge barrier to new market entrants and is in the best interests of dominant vendors (yes it creates extra costs for them, but these are the price for detering competitors).

Engineers will create intendependencies between components and think nothing of it; who does not like easy solutions to problems and this one dependency will not hurt will it? Taking the long term view, and stopping engineers taking short cuts for short term gain, requires a lot of effort; who could fault a Cloud vendor for allowing mutual interdependencies and complexity to accumulate over time.

Error handling is a very important topic that rarely gets the attention it deserves, nobody likes to talk about the situation where things go wrong. Error handling is the iceberg of application development, while the code is often very mundane, its sheer volume (it can be 90% of the code in an application) creates a huge lock-in. The circumstances under which a system handles raises an error and the feasible recovery paths are rarely documented in any detail, it is something that developers working at the coal face learn by trial and error.

Any vendor looking to poach customers first needs to make sure they don’t raise any errors that the existing application does not handle and second any errors they do raise need to be solvable using the known recovery paths. Even if there is error handling information available to enable third-parties to duplicate responses, the requirement to duplicate severely hampers any attempt to improve on what already exists (apart from not raising the errors in the first place).

To create an environment for customer lock-in, Cloud vendors need to encourage engineers to keep doing what engineers love to do: adding new features and not worrying about existing spaghetti code.