bradtraversy

Django 2.x Cheat Sheet

Creating a virtual environment

We need to create a virtual env for our app to run in: More Here Run this command in whatever folder you want to create your venv folder

python -m venv ./venv

wr0ngway

#!/bin/bash

PID=$1
RUBY_BINARY=`which ruby`
BT_FILENAME="/tmp/ruby-backtrace-$PID-$(date +%s).txt"
cmdfile=$(mktemp)

cat <<EOF > $cmdfile
set \$old_stdout = dup(1)
set \$old_stderr = dup(2)

ewherrmann

require 'resque/tasks'

namespace :resque do
  def del(key)
    Resque.redis.keys(key).each { |k| Resque.redis.del(k) }
  end

  desc "Resque setup according to installation guide"
  task :setup => :environment

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

vitobotta

#!/bin/bash

# Also see: http://vitobotta.com/resque-automatically-kill-stuck-workers-retry-failed-jobs/

[[ -f /tmp/retry-failed-resque-jobs ]] && rm /tmp/retry-failed-resque-jobs

ps -eo pid,command | 
grep [r]esque | 
grep "Processing" |
while read PID COMMAND; do  

benfyvie

module ObjectDiagnostics
  extend self

  #This is handy when you want to determine what types of objects are contributing to memory bloat  
  #returns the change in object counts since the last time this method was called
  def change_in_object_counts
    
    #this will start all counts at 0 for the initial run
    @previous_counts ||= Hash.new(0)