ConradIrwin

# If you're looking into the C10M problem (10 million concurrent connections)
# you might want to play with DPDK (Originally proprietry Intel, now open source)
#
# C10M: http://c10m.robertgraham.com/
# DPDK: http://dpdk.org/
#
# This is a quick summary how to install dpdk on ubuntu
# running inside virtualbox on a mac

# On my Mac:

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

hrldcpr

One-line Tree in Python

Using Python's built-in defaultdict we can easily define a tree data structure:

def tree(): return defaultdict(tree)

That's it!