Distributed Computing Fallacies Explained: "The Network Is Homogeneous "

The final Distributed Computing fallacy is "The network is homogeneous."

While the first seven fallacies were coined by Peter Deutsch, I read that the eighth was added by James Gosling six years later (in 1997).

Most architects today are not naive enough to assume this fallacy. Any network, except maybe the very trivial ones, are not homogeneous. Heck, even my home network has a Linux based HTPC, a couple of Windows based PCs, a (small) NAS, and a WindowMobile device--all connected by a wireless network. What's true on a home network is almost a certainty in enterprise networks. I believe that a homogeneous network today is the exception, not the rule. Even if you managed to maintain your internal network homogeneous, you will hit this problem when you would try to cooperate with a partner or a supplier.

Assuming this fallacy should not cause too much trouble at the lower network level as IP is pretty much ubiquitous (e.g. even a specialized bus like Infiniband has an IP-Over-IB implementation, although it may result in suboptimal use of the non-native IP resources.

It is worthwhile to pay attention to the fact the network is not homogeneous at the application level. The implication of this is that you have to assume interoperability will be needed sooner or later and be ready to support it from day one (or at least design where you'd add it later).

Do not rely on proprietary protocols--it would be harder to integrate them later. Do use standard technologies that are widely accepted; the most notable examples being XML or Web Services. By the way, much of the popularity of XML and Web Services can be attributed to the fact that both these technologies help alleviate the affects of the heterogeneity of the enterprise environment.

To sum up, most architects/designers today are aware of this fallacy, which is why interoperable technologies are popular. Still it is something you need to keep in mind especially if you are in a situation that mandates use of proprietary protocols or transports.

Posted by Arnon Rotem-Gal-Oz at 06:53 AM  Permalink