ENTRIES TAGGED "system design"

Why Feedback?

Maintaining a desired behavior

In two previous posts (Part 1 and Part 2) we introduced the idea of feedback control. The basic idea is that we can keep a system (any system!) on track, by constantly monitoring its actual behavior, so that we can apply corrective actions to the system’s input, to “nudge” it back on target, if it ever begins to go astray.

This begs the question: Why should we, as programmers, software engineers, and system administrator care? What’s in it for us?

Read more…

Comment |

Making Systems Operable

Velocity 2013 Speaker Series

There’s an old joke about the aviation cockpit of the future that it will contain just a pilot and a dog. The pilot will be there to watch the automation. The dog will be there to bite the pilot if he tries to touch anything.

Although they will all deny it, the majority of modern IT developers have exactly this view of automation: the system is designed to be self regulating and operators are there to watch it, not to operate it. The result is current systems are often inoperable, i.e. systems they cannot be effectively operated because their functions and capacities are hidden or inaccessible.

The conceit in the pilot-and-the-dog joke is that modern systems do not require operation, that they are autonomous. Whenever these systems are exhibited, our attention is drawn to their autonomous features. But there are no systems that actually function without operators. Even when we claim they are “unmanned”, all important systems have operators who are intimately involved in their function: UAV’s are piloted, the Mars rover is driven, the satellites are managed, surgical robots are manipulated, insulin pumps are programmed. We do not see these activities–many are performed by workers who remain anonymous–but we depend on them.

Read more…

Comments: 2 |
Schlomo Schapiro on continuous delivery platforms

Schlomo Schapiro on continuous delivery platforms

A look at the tech and time that goes into continuous delivery platforms.

Schlomo Schapiro talks about what it's like to develop a continuous delivery platform, including the tech stack and the organizational challenges.

Comment |