Steve Hoeksema steveh

Comparison chips (SoCs) table for ESP8266/ESP32/ESP32-S2/ESP32-S3/ESP32-C3/ESP32-C6

A minimal table to compare the Espressif's MCU families.

	ESP8266	ESP32	ESP32-S2	ESP32-S3	ESP32-C3	ESP32-C6
Announcement Date	2014, August	2016, September	2019, September	2020, December

Common symbols

Modifiers

When a key combination is displayed, the modifiers are written in the order presented here. For example, Control + Option + Shift + Command + Q would be written as ⌃⌥⇧⌘Q.

Sym	Key	Alt
⌃	Control
⌥	Option

DNS:

IPv4 Addr	IPv6 Addr	ASn	Political Region	Loc	Svc	Org
8.8.8.8	2001:4860:4860::8888	AS15169	US	Worldwide (Anycast)	Google Public DNS	Google
8.8.4.4	2001:4860:4860::8844	AS15169	US	Worldwide (Anycast)	Google Public DNS	Google
1.1.1.1	2606:4700:4700::1111	AS13335	US	Worldwide (Anycast)	Cloudflare-DNS	Cloudflare/APNIC
1.0.0.1	2606:4700:4700::1001	AS13335	US	Worldwide (Anycast)	Cloudflare-DNS	Cloudflare/APNIC
95.85.95.85	2a03:90c0:999d::1	AS199524	EU	*W

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

EBS and EFS Volumes with Docker For AWS using REX-Ray

This procedure will deploy Docker For AWS and go through the steps to build REX-Ray containers. This process will have some hiccups because Docker for AWS will provision resources in different availability zones (AZs). Multiple workers/agents will be spread across AZs (not regions) which means a potential host failure will trigger Swarm to restart containers that could spread across an AZ. If a container is restarted in a different AZ, the pre-emption mechanism for REX-Ray will not work because it no longer has access to the volume in the former AZ.

Deploy Docker for AWS.

Launch Stack

SSH into one of your Docker Manager Nodes

	# install xcodes
	brew install robotsandpencils/made/xcodes aria2

	# install & select latest version of xcode
	xcodes list \| awk 'END{system("xcodes install " $1"; xcodes select " $1)}'

	# install x86-64 homebrew
	arch -x86_64 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

	# switch to x86_64 homebrew

	-- Based off IETF draft, https://datatracker.ietf.org/doc/draft-peabody-dispatch-new-uuid-format/

	create or replace function uuid_generate_v7()
	returns uuid
	as $$
	begin
	-- use random v4 uuid as starting point (which has the same variant we need)
	-- then overlay timestamp
	-- then set version 7 by flipping the 2 and 1 bit in the version 4 string
	return encode(

	CC = gcc
	RM = rm -f

	INSTRUMENT_FOR_PROMETHEUS := false

	ifeq ($(INSTRUMENT_FOR_PROMETHEUS),true)
	CFLAGS = -Wall -DINSTRUMENT_FOR_PROMETHEUS
	LIBS = -lbcm2835 -lprom -lpromhttp -lmicrohttpd
	else
	CFLAGS = -Wall

	/*
	Copy this into the console of any web page that is interactive and doesn't
	do hard reloads. You will hear your DOM changes as different pitches of
	audio.

	I have found this interesting for debugging, but also fun to hear web pages
	render like UIs do in movies.
	*/

	const audioCtx = new (window.AudioContext \|\| window.webkitAudioContext)()

	import sys

	# choose() is the same as computing the number of combinations. Normally this is
	# equal to:
	#
	# factorial(N) / (factorial(m) * factorial(N - m))
	#
	# but this is very slow to run and requires a deep stack (without tail
	# recursion).
	#