hellerbarde

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

hotchpotch

# # your config.ru
# require 'unicorn_killer'
# use UnicornKiller::MaxRequests, 1000
# use UnicornKiller::Oom, 400 * 1024

module UnicornKiller
  module Kill
    def quit
      sec = (Time.now - @process_start).to_i
      warn "#{self.class} send SIGQUIT (pid: #{Process.pid})\talive: #{sec} sec"