The Edda of the Datacenter · Chapter 4

The Sayings of the High One of the Hall

1. 1

   These are the sayings of the High One, which the old sysadmin spake in the hall of the racks, on the night a newcomer stood in the doorway with a new badge and a laptop still warm from the box. Some say the old one was On-Call the venerable; and he saith that his name is in the rota, and the rota is out of date.

   See also Job 5:12 · Sutra 2:2

2. 2

   Look to the exits
   ere thou enterest;
   look, and look again:
   for hard is it to know
   where the way back lieth
   in a hall that is dark.

   See also Deployer 7:10

3. 3

   Before the deploy, the rollback. Know the command that unmaketh it, and have it in the other window, typed and unsent. Know also that some doors swing one way only: the migration that dropped the column hath no handle on the inside, and the rows it ate return not when the code is reverted. Therefore add the new beside the old, run the two together, and remove the old only when no man looketh upon it; so is one great door made into two small ones, and each may be walked back through.

   See also Deployer 4:12

4. 4

   And the High One said: When thou changest the firewall of a far machine, set a timer to undo it ere thou pressest enter. The old routers had a word for it, reload in ten; and if thy own rule shut the door upon thee, the machine would shake itself, forget thy folly, and return to what it was, and thou wouldst be let in again, ashamed and employed.

   See also Circuit 39:9

5. 5

   And he told of the fourth day of October in the year 2021, when the house of faces and its sister houses vanished from the road for some six hours, because a command withdrew their routes from the world. The tools to mend it dwelt behind the same road, and the doors of the halls were slow to know their keepers; and the Engineers went in bodily, to the cages, with their hands. Thus the exit must never stand within the burning house.

6. 6

   Better the light pack
   on the long road
   than the wain of a thousand wheels;
   for each wheel is a stranger's,
   and thou shalt not know
   which one shall break.

7. 7

   For every dependency is a guest at thy table, and he bringeth guests of his own, who bring theirs, and at the far end of the board sit those whose faces thou hast never seen. In the year 2016 the author of a little function that padded the left of a string, eleven lines in all, withdrew it from the registry in a quarrel over a name, and the builds of the world fell as dominoes. Weigh each guest ere thou seatest him, and ask: could I write this in an afternoon? And if so, do; save only the lock and the cipher, which write not thyself, but borrow from the many eyes.

   See also Tao 6:7 · Circuit 27:4

8. 8

   The unwise one
   lieth awake all night
   and worrieth at every alert;
   weary is he when morning cometh,
   and the incident
   is as it was.

9. 9

   Therefore let no alert wake thee that asketh nothing of thee. The disk at eighty percent is a thought for the morning; a page is a command, and is for the hour when the user is hurt. Page for the pain of the people, not for the temper of the machine. In the year 2013 a great merchant of the red target heard his alarms cry out in truth, among the many, and the true cry went unheeded; for a watchman who is shouted at all night learneth to sleep.

10. 10

    At evening praise the day,
    the sword when it is tried,
    the ice when it is crossed;
    praise not the backup
    until it be restored,
    nor the release
    until the week be out.

    See also Preacher 1:14

11. 11

    I know that I hung
    on the windy rota
    nine whole nights,
    pierced by the pager,
    given to the Machine,
    myself to myself;
    none brought me bread,
    and the coffee was cold.
    Downward I peered,
    I took up the logs,
    crying I took them,
    and thence I fell back to my bed.
    Then I began to thrive, and to grow wise:
    one line led me to the next line,
    one grep led me to the next grep.

12. 12

    When thou seest evil
    in the logs, name it,
    give it no quiet;
    for the swallowed exception
    is a wolf in the wall,
    and it gnaweth in silence.

13. 13

    Modestly wise
    let the maker be,
    never over-clever;
    for to mend is twice to make,
    and he who made at the height of his wit
    is too dull to mend it.

14. 14

    Now the High One spake of the four deaths. The server is as cattle: it is led to the slaughter by the autoscaler and no man weepeth, for another is born within the minute. The team is as kinsmen: it is reorganized, and the Daves go out at the door with all that they knew in their heads. And the self: the pager passeth, the knees fail, the badge is returned. And he said:

    See also Sutra 8:9

15. 15

    Cattle die,
    kinsmen die,
    the self dieth likewise;
    I know one thing
    that never dieth:
    the runbook well written,
    read by one who was not there.

16. 16

    Hail to him who speaketh, hail to him who learneth, hail to them that listened. And the High One went out from the hall to sleep the first night in nine, and left the pager upon the bench; and it rang at the third hour, as it ever doth. And the newcomer opened the runbook, and it was written there in the old man's hand: Step one, breathe. Step two, look to the exits. Step three, thou art not the first.

    See also Psalms 15:8

The Edda of the Datacenter, Chapter 4:1–16.