Posts related to fallacies

Fallacy #8: The network is homogeneous

Interoperability is painful.

Around 2005 or 2006, it wasn’t so bad. Most of the code running on the planet, at least the code that mattered, was written in .NET or Java, and interoperability via web services was at least serviceable. Since then, things have gotten gradually worse.

First came Ruby and Ruby on Rails. In the early days, it did not support web services like other platforms did. Next came the dawn of the NoSQL movement, driven at least partially by large companies with no incentive to interoperate. Google built BigTable, Amazon built Dynamo, Facebook built Cassandra, LinkedIn came up with Voldemort. None of these things can talk to each other.

Then came REST, or in other words, “something I invented myself over HTTP.” Each RESTful endpoint is that developer’s definition of what REST means, which is different from what every other developer thinks REST means.

Competitive pressures, together with companies’ desire to create vendor lock-in, suggest that we can expect more divergence to occur in the future.

Fallacy #7: Transport cost is zero

Of course, there are upfront and ongoing costs associated with any computer network. The servers themselves, cabling, network switches, racks, load balancers, firewalls, power equipment, air handling, security, rent/mortgage, not to mention experienced staff to keep it all running smoothly, all come with a cost.

Companies today have, for the most part, accepted this as just another cost of doing business in the modern world.

With cloud-based server resources, this equation changes only slightly. Instead of paying for a lot of these things upfront, we instead lease them from the cloud providers. It may change how a company can represent these costs on a balance sheet, but overall, it’s the same concept.

But, we also have to pay for bandwidth. In order to connect our data center to the rest of the world, we must exchange currency for the transport of our bits and bytes. In the cloud, we must pay this also, whether directly or as part of the cost of whichever service we’re using.

Fallacy #6: There is one administrator

In small networks, it is sometimes possible to have one administrator. This is usually the developer who creates and deploys a small project. As a result, this developer has all of the information about this project readily available in their head and, if anything goes wrong, will know precisely what to do.

I know quite a few developers and managers who talk about “bus theory” as a way to promote communication of critical knowledge. The central point is this: having only one person holding critical knowledge is dangerous because of what would happen if that person got run over by a bus. The term bus factor was coined to represent the number of people on your team who have to be hit by a bus before the project is in serious trouble.

Fallacy #5: Topology doesn't change

It’s easy for something that started out simply to become much more complicated as time wears on. I once had a client who started out with a very noncomplex server infrastructure. The hosting provider had given them ownership of an internal IP subnet, and so they started out with two load-balanced public web servers: X.X.X.100 and X.X.X.101 (Public100 and Public101 for short). They also had a third public web server, Public102, to host an FTP server and a couple random utility applications.

And then, despite the best laid plans, the slow creep of chaos eventually took over.

Fallacy #4: The network is secure

There are a myriad of security-obsessed organizations scattered throughout the world that take security concerns to the verge of paranoia.

In one such organization I’ve heard of, there existed two separate networks. Everyone had two computers without external disk drives of any kind. Inserting a USB drive would not work, and trying to use one would instantly alert the sysadmins that a workstation was compromised. To get data from a different network, you needed to browse in a separate room, as workstations did not have access to the Internet.

Once you found the data you needed, you could download it to a floppy disk and then hand the floppy over to a sysop. The sysop would copy the contents to a mirror folder, which would analyze the contents with every virus scanner imaginable before mirroring them to the development network. But that sync only occurred once per hour.

Paranoid? Maybe. If you’re just selling widgets on a website, then probably. But if your organization is working on defense contracts or controls critical infrastructure like electrical grids, perhaps the paranoia is justified.

The only truly secure computer is one that is disconnected from any and all networks, turned off, buried in the ground, and encased in concrete. But that computer isn’t terribly useful.

Fallacy #3: Bandwidth is infinite

Everyone who is old enough to remember the sound of connecting to the Internet with a dial-up modem or of AOL announcing that “You’ve got mail” is acutely aware that there is an upper limit to how fast something can be downloaded, and it never seems to be as fast as we would like it.

The availability of bandwidth increases at a staggering rate, but we’re never happy. We now live in an age when it’s possible to stream high definition TV, and yet we are not satisfied. We become annoyed when we run a speed test on our broadband provider only to find that, on a good day, we are getting maybe half of the rated download speed we are paying for, and the upload speed is likely much worse. We amaze ourselves by our ability to have a real-time video conversation with someone on the other side of the world, but then react with extreme frustration when the connection quality starts to dip and we must ask “are you there?” to a face that has frozen.

Today, we have DSL and cable modems; tomorrow, fiber may be widespread. But although bandwidth keeps growing, the amount of data and our need for it grows faster. We’ll never be satisfied.

Fallacy #2: Latency is zero

The speed of light is actually quite slow. Light emitted from the sun this very instant will not reach us here on Earth for 8.3 minutes. It takes a full 5.5 hours for sunlight to reach Pluto and 4.24 years to reach our closest neighboring star, Proxima Centauri. And we cannot communicate at the speed of light; we must bounce data around between Ethernet switches, slowing things down considerably.

Meanwhile, human expectations of speed are pretty demanding. A 1993 Nielsen usability study found that, for web browsing, a 100 millisecond delay was perceived as reacting instantly, and a one second delay corresponded to uninterrupted flow. Anything more than that is considered a distraction.

Fallacy #1: The network is reliable

Anyone with a cable or DSL modem knows how temperamental network connections can be. The Internet just stops working, and the only way to get it going again is to unplug it for 15 seconds. (Or, put another way, “Have you tried turning it off and on again?”)

Thankfully, better solutions exist for professional data centers than consumer-grade modems, but problems can persist.

As a company that does reliable messaging, we’ve really heard it all. Don’t worry, the names will be changed to protect the innocent.