pjotrp

Notes from the Mystery Machine Bus

I've spent the past eight years (starting back in June 2004) writing elaborate rants about a bunch of vaguely related software engineering issues.

I was doing all that ranting because I've been genuinely perplexed by a set of "bizarre" world-views held dear by -- as far as I can tell -- about half of all programmers I encounter, whether online or in person.

Last week, after nearly a decade of hurling myself against this problem, I've finally figured it out. I know exactly what's been bothering me.

In today's essay I'm going to present you with a new conceptual framework for thinking about software engineering. This set of ideas I present will be completely obvious to you. You will probably slap yourself for not having thought of it yourself. Or you might slap the person next to you. In fact you probably have thought of it yourself, because it is so blindingly obvious.

pjotrp

#!/bin/bash

# Usage:   ./honeywell_settmp.sh [-c|-h|-o] [<temp(F)>|schedule]
# Example: ./honeywell_settmp.sh -h 72        # set HEAT: temp=72F
#          ./honeywell_settmp.sh -c schedule  # set COOL: follow shceduled temp
#          ./honeywell_settmp.sh -o           # turn system OFF

######## Settings ########
LOGIN="YOUR_MAIL_ADDRESS"
PASSWORD="YOUR_PASSWORD"

pjotrp

L1 cache reference                  0.5 ns
Branch mispredict                   5 ns
L2 cache reference                  7 ns
Mutex lock/unlock                   25 ns
Main memory reference               100 ns
Compress 1K bytes with Zippy        3,000 ns
Send 2K bytes over 1 Gbps network   20,000 ns
Read 1 MB sequentially from memory  250,000 ns
Round trip within same datacenter   500,000 ns
Disk seek                           10,000,000 ns