Mahmoud Hashemi mahmoud

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

General Background and Overview

Probabilistic Data Structures for Web Analytics and Data Mining : A great overview of the space of probabilistic data structures and how they are used in approximation algorithm implementation.
Models and Issues in Data Stream Systems
Philippe Flajolet’s contribution to streaming algorithms : A presentation by Jérémie Lumbroso that visits some of the hostorical perspectives and how it all began with Flajolet
Approximate Frequency Counts over Data Streams by Gurmeet Singh Manku & Rajeev Motwani : One of the early papers on the subject.
[Methods for Finding Frequent Items in Data Streams](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.187.9800&rep=rep1&t

Update HISTORY.md
Commit the changes:

git add HISTORY.md
git commit -m "Changelog for upcoming release 0.1.1."

Update version number (can also be minor or major)

bumpversion patch

	from sqlalchemy import event
	from sqlalchemy import DDL


	def _mysql_cidr_overlap(metadata):
	@event.listens_for(metadata, "after_create")
	def _create_mysql_proc(target, connection, **kw):
	if connection.engine.name != 'mysql':
	return

	'''
	Simple distributed, streaming algorithm for keeping counts on
	an adaptive sample of data.
	'''
	import time
	import hashlib
	import json
	import base64

	'''
	Converts functions into simple commands.
	Turns function arguments into command line arguments, and docstrings into helpstrings.
	Essentially an argparse shortcutter.

	e.g.

	@f2cmd.cmd(arg1={"type": int})
	def my_main_function(arg1, arg2):
	pass

	#!/usr/bin/python
	import serial
	import sys

	latestByte = ('c')
	lastByte = ('c')
	inPacket = False
	myPacket = []
	PLENGTH = 0

	# -- coding: utf-8 --

	IRREGULAR_PLURALS = {'alumnus': 'alumni',
	'cactus': 'cacti',
	'focus': 'foci',
	'fungus': 'fungi',
	'nucleus': 'nuclei',
	'radius': 'radii',
	'stimulus': 'stimuli',
	'axis': 'axes',

	license: gpl-3.0
	height: 960
	redirect: https://observablehq.com/@d3/d3-zoomable-circle-packing