Thursday, 16 June 2011

Five Nines

In High Availability we talk about "Five Nines" meaning 99.999% availability. I like to joke that a badly configured system has "Nine Fives" availability or 55.555555% availability.

With a sensible architecture and good operational controls, data can be made "Five Nines" safe with PostgreSQL 9.1.

I was reminded today that "Five Nines" had another meaning in an earlier age. Wilfrid Owen's wartime poetry describes

And towards our distant rest began to trudge.
Men marched asleep. Many had lost their boots
But limped on, blood-shod. All went lame; all blind;
Drunk with fatigue; deaf even to the hoots
Of tired, outstripped Five-Nines that dropped behind.

meaning artillery shells falling away from the target of the front line troops.

The poem ends with an exhortation to learn from earlier mistakes

My friend, you would not tell with such high zest
To children ardent for some desperate glory,
The old Lie: Dulce et decorum est
Pro patria mori.

"How sweet and fitting it is to die for one's country"

I'm sure there's a modern message there, but I'll leave that up to you.

1 comment: