hugohenley

Latency numbers every programmer should know

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  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

hugohenley

#!/usr/bin/env bash

# Generate timestamped filename
TIMESTAMPED_TAG=`date +%Y-%m-%d-%H%M%S`
BACKUP_ARCHIVE="./jenkins-backup-${TIMESTAMPED_TAG}.tar.gz"

# Inconceivable race condition avoidance
if [-f $BACKUP_ARCHIVE ]; then
	rm ${BACKUP_ARCHIVE}
fi