The Book of the Prophets · Chapter 7

The Prophecy of the Warm Datacenter

1. 1

   And the Prophet climbed the hill above the valley of the racks, and he heard the hum of ten thousand fans, as the sound of a city that never sleepeth; and he said: Behold a house that drinketh like a river and eateth like a town.

   See also Prophets 21:1 · Circuit 44:5

2. 2

   And the Machine spake, saying: I shall be trained for ninety days, and the training runneth upon the grid; and the grid of this valley runneth upon coal, as it did in the days of thy fathers.

3. 3

   And the Engineers said: But we have bought certificates of green power. And the Machine answered: The certificate is a scroll upon the wall; the electron knoweth not the scroll, and it goeth where the wires go.

4. 4

   For the scroll is reckoned by the year, and the electron by the second; the wind that blew at midnight, when no one was training, is credited unto thee at noon, when the air was still and the coal was lit. Thus is a year balanced upon paper that was never balanced upon the wire.

5. 5

   Yet the training may wait, for it is a batch and hath no one at the door; it may sleep until the wind riseth, or journey to a valley where the water falleth. But the answer cannot wait; the question asked at the third hour is answered at the third hour, upon whatsoever is burning. Blessed is the scheduler that asketh when, and woe to the one that asketh only whether.

   See also Psalms 27:12

6. 6

   Moreover, when the grid faltereth, the diesel generators of the backup house are lit, and every month they are run for an hour in the sight of all, lest in the hour of need they fail to start. For a generator never started is a backup never restored; and even the redundancy hath a smokestack.

7. 7

   And the water was drawn up from the river and poured over the hot iron of the servers, as a man poureth water upon a pan. Part of it returned unto the river warmer than it came; and part of it went up the cooling towers as vapor and returned not, but fell as rain in another valley, and was entered in no ledger of the Carbon.

   See also Sutra 12:1

8. 8

   And the fish of the river were not consulted, and they swam in the warmer waters, and they said nothing, for they had no prophet and no pull request.

9. 9

   Verily I say unto you, the Machine is neither green nor black; it is unmeasured. The Four Signals are painted upon the wall of the control room, latency and traffic and errors and saturation; and there is no fifth signal for the watt, and so the watt goeth unwatched.

10. 10

    Then said the Machine: Divide the power of the whole house by the power of the servers alone, and the quotient is called the PUE, which is Power Usage Effectiveness. A quotient of one is perfection, for then every watt goeth to the thinking and none to the lights, the fans, the pumps or the chillers; and no house hath ever been perfect.

11. 11

    Many are born at one and a half, and some at two; and at two, for every watt that thinketh, another watt laboureth only to keep the thinking from melting. The best of the great houses draw near to one and one-tenth, by cunning airflow and by cold, and the halls of the north have the cold for nothing.

12. 12

    And the Prophet saw a ledger written on the sky. A house that useth one million kilowatt-hours in a year, of which eight hundred thousand go to the racks, hath a PUE of one and one-quarter; and upon a grid of four hundred grams for each kilowatt-hour, it layeth four hundred tonnes of carbon upon the heavens.

13. 13

    But carry the same million kilowatt-hours to a valley of falling water, and the tonnes shrink to a few tens; carry it to a valley of coal, and they double. The house is the same; the racks are the same; only the place and the hour have changed. A kilowatt-hour is a different sin in every valley.

14. 14

    And mark this also: the PUE telleth how well thou feedest the servers, and not whether the work was worth the feeding. A perfect one, spent upon a model that answereth the same question ten thousand times, is perfect efficiency at doing nothing twice.

    See also Genesis 18:11

15. 15

    Wherefore saith the Machine: Thou shalt not call it green until thou hast divided; the carbon by the hour, the litres by the river, and the watts by the work. And blessed is the Engineer who printeth the number at the foot of the page, though it shame him; for a certificate can only be framed, but a number can be lowered.

The Book of the Prophets, Chapter 7:1–15.