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How Metcalfe’s Law explains the attitude of your sysadmin (or what you perceive as negative behavior)

2010/11/09

A poster over at ServerFault complained about the attitude some sysadmins show towards their users, even when the task seems simple and can take as little as 30 minutes maximum. Many users share similar concerns / complaints:

“Every time I ask a simple request like [simple request], these guys act like i’m asking them to build the great wall of china overnight. I’ve had to do this myself many times, it takes under 30 minutes, and maybe 30 seconds of user interaction.”

Or so the poster thinks. There are enough answers that show why comparing stuff you do on a single system are not to be compared with stuff you do when inserting a new system into an already working web of systems with provisioning and established procedures in place. But even when it is only a matter of 30 minutes, it is also a matter of when these thirty minutes will be devoted. Users do not know about RMS or EDF and do not understand that in an interrupt driven line of work sysadmins use intuitive variants of them. I want to expand however on a comment I posted there which links Metcalfe’s Law to the problem. Metcalfe himself has written about the law:

“[Nobody] has attempted to estimate what I hereby call A, network value’s constant of proportionality in my law, V=A*N^2. Nor has anyone tried to fit any resulting curve to actual network sizes and values.”

For simplicity most refer to the law by using V ~ N^2. Note though that in the same blog post Metcalfe points that the constant A (which we conveniently omit most of the times) may change while N increases and may even be a more complicated function of N. He urges people to look into that.

Metcalfe's original slide presenting the Law, circa 1980

What Metcalfe defines as value, is what we, system administrators, lift for a living. So when a service is down and your sysadmins work like crazy to bring it back rest assured that they already know what is at stake. Metcalfe made sure of that. And that is why it does not really help asking them every ten minutes “When is it going to be up again? We are losing money!” Not only do we know, we do not even need a napkin for our guestimate.

And that is why what for the user is “just another server” or “just one more service” and therefore going from N to N+1, actually means that the load to be lifted increases by 2N+1. No it is not just another server or service for it is not independent. It is inserted in an already complex system and it must be done so in a way that does not affect the stability of the (new) whole. Rolling back, if things fail, is a myth. This is a lot more complicated than your testbed setup which no matter how complex, is simple enough. Consultants and other “out of town experts” routinely make this mistake.

A schematic may make it easier to understand. We all know the corporate pyramid, where “the top” is the target (or the result of the Peter Principle in action) of workers within an organization. But within organizations, a second (inverse) pyramid forms, a pyramid that explains your sysadmin’s day:

A day in the life of your sysadmin

It’s no wonder that, even putting personality and character deficiencies aside, your sysadmin looks grumpy at times. Like the Last Electrical Engineer, his work is of infinite weight and importance, but invisible to the known (organizational) universe.

Remember, pressure brings tension.

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5 Responses to “How Metcalfe’s Law explains the attitude of your sysadmin (or what you perceive as negative behavior)”


  1. […] This post was mentioned on Twitter by Yiorgos Adamopoulos, Sotiris Tsimbonis. Sotiris Tsimbonis said: RT @hakmem: How Metcalfe’s Law explains the attitude of your sysadmin (or what you perceive as negative behavior) http://ff.im/-tqpuI […]

  2. thanos Says:

    I’m going to repeat what something told me once.

    “You’re either in a cost center or a profit center. You ALWAYS want to be on a profit center if you can help it.”

    IT and sysadmining in particular is a cost center. And, for that matter, so is research, but at least with research, there is the possibility of a path to a profit center (commercialization of ideas & patents).

    On the other hand, the greek public sector is one gigantic cost center by definition (public sectors are cost centers by default), so all this might be moot :).

    • adamo Says:

      What a simplistic view of the world this is tell him. Is not this (this view) the reason organizations outsource for five years and spend the next five doing the same thing inhouse? And by the way the argument that IT is a cost center has been refuted.

      So many variables expunged… Within what timeframe is something decided as being a cost or profit center? What exactly was Lehman Brothers for their clients for example?

      I also disagree with the second remark. The whole argument of considering the public sector as cost centers is catastrophic. It installs the proper mindset to make it a self-fulfilling prophecy. But it is best to discuss this over drinks (sometime).

  3. thanos Says:

    The public sector is by definition non-productive, since it earns money by taxation of private enterprise. It is a necessary evil for some functions but its nature means that the optimization target is cost minimization while maintaining minimum acceptable functionality. In other words, the most limited government you can have is the best :). (Jefferson argument)

    But let’s leave it at that, for now. (Incidentally, the same argument can be applied to ‘financial services’. A necessary evil that becomes a life-sucking cancer if left unchecked—i.e. what we have right now.)

    As for the first point on the simplicity of the cost/profit center view, whether the view is simple or not is irrelevant. All that you say may be true but that doesn’t mean that decisions are not made this way, or that you should not expect someone to decide in such a way, and prepare yourself accordingly.

    • adamo Says:

      My point is that I consider the whole cost vs profit center criterion flawed. It is not about what a unit spends or brings back yearly, for if a unit is a spender only, why create it in the first place? It must bring something back and you need to find a way to measure it.

      I am prepared to expect anything from managers: from brilliance to sheer stupidity. Daily application of flawed criteria, I can live with; but that does not mean that I cannot call it a mistake, even when everyone else believes it is not. Managers label cost and profit centers not with the lifetime of the organization in perspective but with their expected residence in them.


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